This document provides an overview of mechanical components and maintenance for a Malaysian polytechnic handbook. It covers topics such as maintenance principles, procedures, lubrication, power transmission, bearings, clutches and brakes, pumps, valves and compressors. The document includes learning outcomes, definitions of maintenance, types of maintenance such as breakdown, preventive and predictive, and discusses safety practices, tools, costs and other aspects of maintenance. Chapters cover specific mechanical systems and components, how to inspect and maintain them, and develop maintenance procedures and checklists. Practical assemblies and disassemblies of components are also suggested as examples.

1. MECHANICALCOMPONENTSAND MAINTENANCE
FOR MALAYSIAN POLYTECHNIC HANDBOOK
©2013Department of Polytechnic Education, Ministry of Higher Education, MALAYSIA.
ALL RIGHTS RESERVED

2. The text of this publication, or any part thereof, may not be reproduced or transmitted in anyform
or by any means, electronic or mechanical, including photocopying, recording, storage inan
information retrieval system, or otherwise, without prior permission of Department of
Polytechnic Education.
Preface
MECHANICALCOMPONENTSAND MAINTENANCEcoversbasicmechanical
componentsneedsinIndustry.Thetopicincludesmaintenanceprinciples,procedures,
lubrication,powertransmission,bearing,clutches and brakes and pumps,valves and
compressor.Thiscoursealsogivesknowledgeandskillsregardingmaintenanceof mechanical
componentsand assemblies.
Editor
Arman Bin Md Said

3. Table of Contents
1.0 MAINTENANCEPRINCIPLESANDPROCEDURES
1.1 Understandingof maintenance.
1.1.1 Definethemeaningofmaintenance.
1.1.2 Describe theobjectiveandadvantagesofimplement
maintenance.
1.2 Explain various types of cost maintenance related.
1.3 Describeworkplacesafety.
1.3.1 Identifythebenefitcleanandsafeworkingenvironment.
1.3.2 Explaintheimportantof personal protectionequipments.
1.3.3 Uselockoutandtag-outwhenneeded.
1.3.4 Identifyalltheorganizationthatgovernsthesafetyof
hazardousmaterial.
1.4 Identifytypesofhand tools,powertoolsandmaintenanceequipments.
1.4.1 Listthe mostcommon typesofhand tool andpowertools.
1.4.2 Demonstratetheproperuseofvarious typesofhandtooland powertools.
1.4.3 Determine theimportanceofinspectingahand toolandpower
tools
2.0 LUBRICATION
2.1 Understandlubrication principle.
2.1.1 Describelubricationsystemandbenefitimplement
lubricationsystem.
2.1.2 Stateseveralterm andprincipletounderstandandselect proper
lubrication.
2.2 Understandfluidmanagement.
2.2.1 Applyfouressentialcomponentsina fluid management
program.
a. Selectionandpurchaseoflubrication
b. Lubricationmonitoringduringuse
c. Lubricantmaintenanceusingprocessing d.
Refortificationtechniques
e. Disposalofthespentlubricant.
2.3 Identifylubricatingdevicesandsystem.
2.4.1 Evaluateeffectivenesslubricatesuchasselectrightlubricant
type,place, amountandtimeto use.
2.4.2 Choosesuitable lubricatingdevices systembased onequipment
ormechanical components.
3.0 POWERTRANSMISSION

4. 3.1 Describethedrivemechanismintheprocessoftransformingpower fromone
pointtotheother.
3.1.1 Classifytypesof drivemechanismsbeltdrive, chaindrive and gear
drive
3.2 Describegear in powertransmissionsystem.
3.2.1 Listapplicationofgear.
3.2.2 Classifytypes ofgearsandtheir characteristics basedonit‘s
function.
3.2.3 Identify gearmeshingandbacklash.
3.2.4 Explain coupling concept into gear system.
3.2.5 Identifygearmaintenancepracticesuchasdailyroutine
inspection.
3.2.6 Developgearchecklistforpreventivemaintenance,symptoms
andrecord observationforpreventive maintenance ,etc.
3.2.7 Assembleanddisassembleafewtypesofgearsa practical.As an examples
componentscanbeuseisassemblyspurgearexercise or assemblyspur
wheel /wormgear station.
3.2.8 Developmaintenanceprocedure.
a. Geartooth-wearandfailure.
b. Lubrication contaminationandincorrectlubrication.
c. Overheating.
d. Lowoillevel,etc
3.3 Definebeltdrives inpower transmissionsystem.
3.3.1 Listapplicationofbeltdrives.
3.3.2 Classify FIVE typesofbelt
drivesandtheircharacteristicsbasedonit‘sfunction.
3.3.3 Identifybelttensionand misalignmentofbeltdrives.
3.3.4 Developedchecklistdrives belt maintenance, symptoms and
recordobservationsforpreventive maintenance.
a. Prematurebeltfailure.
b. Severeorabnormalbeltwear. c.
Banded(joined)beltproblems.
d. Beltnoiseandunusualvibration.
e. Problemswithsheaves,beltstretchesbeyondtakeup. f. V-
beltturnoverorjumpoffsheave,etc
3.3.5 Producebeltdrivemaintenanceprocedure.
3.4 Understandchain drive.
3.4.1 List applicationof chaindrive.
3.4.2 Classify FIVEtypesofchaindrive and theircharacteristicsbased
onit‘sfunction.
3.4.3 Developchecklistchaindrivemaintenance,symptomsand
recordobservationforpreventive maintenance.
3.4.4 Producechaindrivemaintenanceprocedure.
3.5 Implementcoupledshaftalignment orvariable-speed drives.

5. 3.5.1 Describethefundamentalsofshaftalignment.
3.5.2 Demonstratetheuseof thereversedialindicatormethodsto correct
shaft misalignment.
3.5.3 Assembleanddisassembleofmechanicaldrivesystemasa
practical.Asanexamples components canbeusearegear
assemblyforcombined drivesandalignment of drives, shafts
andgear.
4.0 BEARING
4.1 Understandbearingconcepts.
4.1.1 Listapplicationof bearing.
4.1.2 Classify FIVE types of bearing based on its application.
4.1.3 Identify bearing numenclature and code base on ISO
4.1.4 Explain Bearing Service Life, in hour or rotation
4.1.5 Explain the concept ofseals,gasketsandpackingintobearing
system.
4.2 Understandfriction, temperature andlubrication.
4.2.1 Identifyfrictioninbearingsystem.
4.2.2 Relateoperatingtemperaturewithbearingfriction.
4.2.3 Identify principleofbearinglubrication.
4.3 Describe mountinganddismountingofbearing.
4.3.1 Applymountinganddismountingequipment andtools.
4.3.2 Usemeasuringequipmentforbearinginstallation.
4.3.3 Applyconcepttoadjusting theclearanceduringinstallation.
4.3.4 Classifymountingmethods likes cold mounting,temperature
mounting,mounting tapered-borebearing,dismountingof
bearing,hydraulic method.
4.3.5 Assembleanddissembleofbearingasapractical.As anexamples
componentscanbeuseare assemblyshaftwith journal
bearingsandassemblyhydrodynamic journal bearing.
4.4 Understandbearingdamage.
4.4.1 Developedbearing maintenance check list,symptoms
forpreventive maintenance.
a. Fatigue,vibrationandwear
b. Corrosiondamage.
c. Scuffingandslidingmarks.
d. Localindentationsintheraceway.
e. Faultymountinganddefectiveinstallationmethods.
f. Poorlubricationand faultindesign.
5.0 CLUTCHES ANDBRAKES

6. 5.1 Describe clutchesandbrakesprinciple.
5.1.1 Identifyfunctionofa clutch and brakes.
5.1.2 Classify various typesof clutches based on:
i- Mechanical
ii- Electric and
iii- Hydraulic
5.1.3 Assembleanddissembleclutch and brake as a practical
.Components canbeuseare multiple plate clutch and drum
brakes
5.2 Develop clutchesand brakes maintenance procedure
5.2.1 Developedchecklist clutchesand brakesmaintenance
,symptomsandrecordobservationsforpreventive maintenance.
6.0 PUMPS,VALVESANDCOMPRESSOR
6.1 Understandpumpsconcepts.
6.1.1 Listapplicationofpumps.
6.1.2 Classifytypes ofpumpsbasedonit‘s
principle.
i. Positive displacement
ii. Rotor dynamic
6.1.3 Assembleanddisassemblepumpasapractical.Asaexamples
componentscanbeuseiscentrifugal pump.
6.1.4 Developedcheck list pumpsmaintenance,symptomsandrecord
observationsforpreventive maintenance.
6.2 Understand valve concepts.
6.2.1 Listapplicationofvalve.
6.2.2 Classify FOURtypes of valveandtheir characteristics basedonit‘s
function.
i. Butterfly
ii. Gate
iii. Ball
iv. Globe
6.2.3 Assembleanddisassemblea fewtypesofvalveasapractical.
Asanexamplesapparatuscanbeuseareassemblygate valve andangleseat
valve,assemblybutterflyvalve and non-return valve,assemblyball
valve andglobe valve.
6.2.4 Developedchecklistvalvemaintenance,symptomsand
recordobservationsforpreventive maintenance.
6.3 Understandcompressor concepts.
6.3.1 Listapplicationofcompressor.
6.3.2 Classifytypesofcompressor based on it‘sfunction.
i. Positive displacement

7. iii. Rotor dynamic
6.3.3 Identifyprinciple andcharacteristicofcompressor.
6.3.4 Determinecompressormaintenanceconcept.
Assembleanddisassembleafewtypesofacompressorasapractical.Asanex
amplescomponentcanbeuse ispiston
compressor.
6.3.5 Developedchecklistcompressormaintenance,symptoms
andrecordobservations forpreventivemaintenance.
2.4 Determinelubricatingprogram.
a. Theplantlubricationsurvey.
b. Establishmentoflubricationschedulesand improvementsin
selection and applicationoflubrication.
c. Lubricationanalysis
INDEX
REFERENCES

8. 1Hashimi Bin Lazim (PTSS)
Zulkifli Bin Sulaiman (POLIMAS)
1.0 MAINTENANCEPRINCIPLESANDPROCEDURES
Introduction
Maintenance, repair, and operations (MRO) or maintenance , repair, and overhaul involve fixing
any sort of mechanical, plumbing or electrical device should it become out of order or broken
(known as repair, unscheduled or casualty maintenance). It also includes performing routine
actions which keep the device in working order (known as scheduled maintenance) or prevents
trouble from arising (preventive maintenance). MRO may be defined as, "All actions which have
the objective of retaining or restoring an item in or to a state in which it can perform its required
function. The actions include the combination of all technical and corresponding administrative,
managerial, and supervision actions.
1.1 Understandingof maintenance.
1.1.1 Definethemeaningofmaintenance.
I. Based on language maintenance is activities required or undertaken to conserve as
nearly, and as long, as possible the original condition of an asset or resource while
compensating for normal wear and tear.
II. The definition of maintenance often stated maintenance as an activity carried out for
any equipment to ensure its reliability to perform its functions.
III. In engineering maintenance are actions necessary for retaining or restoring a piece of
equipment, machine, or system to the specified operable condition to achieve its
MAINTENANCEPRINCIPLESANDPR
OCEDURES
Learning Outcomes
Upon completion of this chapter, students should be able to:-
1. Understandingof maintenance.
2. Explain various types of cost maintenance related.
3. Describeworkplacesafety.
4. Identifytypesofhand tools,powertoolsandmaintenanceequipments.

9. maximum useful life. It includes corrective maintenance and preventive maintenance.
IV. Maintenance is work that is carried out to preserve an asset (such as a roof or a
heating boiler), in order to enable its continued use and function, above a minimum
acceptable level of performance, over its design service life, without unforeseen
renewal or major repair activities.
1.1.2 Types of Maintenance
I. Breakdown maintenance
It means that people waits until equipment fails and repair it. Such a thing could be
used when the equipment failure does not significantly affect the operation or
production or generate any significant loss other than repair cost
II. Preventive maintenance ( 1951 )
It is a daily maintenance (cleaning, inspection, oiling and re-tightening), design to
retain the healthy condition of equipment and prevent failure through the prevention
of deterioration, periodic inspection or equipment condition diagnosis, to measure
deterioration. It is further divided into periodic maintenance and predictive
maintenance. Just like human life is extended by preventive medicine, the equipment
service life can be prolonged by doing preventive maintenance
a) Periodic maintenance (Time based maintenance - TBM)
Time based maintenance consists of periodically inspecting, servicing and cleaning
equipment and replacing parts to prevent sudden failure and process problems.
b) Predictive maintenance
This is a method in which the service life of important part is predicted based on
inspection or diagnosis, in order to use the parts to the limit of their service life.
Compared to periodic maintenance, predictive maintenance is condition based
maintenance. It manages trend values, by measuring and analyzing data about
deterioration and employs a surveillance system, designed to monitor conditions
through an on-line system.
III. Corrective maintenance ( 1957 )
It improves equipment and its components so that preventive maintenance can be

10. carried out reliably. Equipment with design weakness must be redesigned to improve
reliability or improving maintainability
IV. Maintenance prevention ( 1960 )
It indicates the design of a new equipment. Weakness of current machines are
sufficiently studied ( on site information leading to failure prevention, easier
maintenance and prevents of defects, safety and ease of manufacturing ) and are
incorporated before commissioning a new equipment
1.1.3 Describe theobjectiveandadvantagesofimplement maintenance.
The purpose of maintenance is to attempt to maximize the performance of equipment by
ensuring that such equipment performs regularly and efficiently, by attempting to prevent
breakdowns or failures, and by minimizing the losses resulting from breakdowns or failures. In
fact it is the objective of the maintenance function to maintain or increase the reliability of the
operating system as a whole.
The maintenance function has not, during the past years, been seen as a condition for production.
Instead the previous action approach was that the maintenance was the necessary evil which only
consumed a lot of money. Very often the maintenance cost was seen too high.
This way of seeing maintenance was a sign of that the only objective of maintenance was to
repair and mend broken equipment. This is the old fashioned way of maintenance management.
In modern maintenance management, it is not recommendable to concentrate 100% on
breakdown jobs and repairing. Modern maintenance management is to keep the equipment into
operation and produce quality products meaning that every time we need to do a unplanned
repair work, we have not succeeded with the maintenance strategy.
In fact the objective of the maintenance activity is a priority one to work for a planned
availability performance and priority two is to do this at the lowest cost possible. Obviously the
safety aspects must also be taken into consideration.
The objective of maintenance in the industry is: - To achieve the correct level of operational
reliability and best possible personal safety at minimum cost. Or in another words the objective
of maintenance can be mentioned as follows: - To keep up the planned availability performance
at the lowest cost and within the safety prescriptions.
Planned availability performance means that the production manager and maintenance manager
have agreed on the availability performance for a certain period of time in the future.
It is essential to mention that the target of availability performance is decided first, secondly the
cost factors are taken into consideration.
This objective can also be described as an attempt to achieve the optimum or best possible
operational reliability i.e. the most economical operational reliability at as low a cost as possible.
In order to achieve this, a number of measures are employed, some of which are described
below.

11. I. Planning of work improves the likehood of ensuring that the correct work is
carried out at the right time. Planning also provides information for purchasing
spare parts and materials and for determining personal requirements.
II. Various means of learning from experience can also be employed. One way is to
keeprecord every operational problem. This data can be used as a basis for
planning.
III. Maintenance can also be facilitated through design changes, improved lubricants,
improved suspension system etc., all of which can reduce the need for
maintenance.
IV. It is important to reduce maintenance requirements when maintenance work is to
be rationalized.
V. Within the majority of areas, the amount of maintenance work necessary can be
reduced through improved application of experience, improved planning and
better design, coupled with application of suitable methods of investigating the
condition of plant and machinery (condition monitoring).
VI. Maintenance contributes to reduced consumption of capital by helping to
maintain the value of materials and equipment.
VII. Correct maintenance also extends the life of the equipment. This means that fund
that would otherwise have been required to invest in (i.e. purchase) new
equipment, can be used for other purposes within the company.
VIII. The way in which maintenance is carried out in a company is of considerable
economic importance. Proper maintenance increases reliability and, therefore,
productivity, resulting in increased revenue.
Most of the measures described above result in less time and material being required for
maintenance, leading to reduced costs for the company. In general, it can be said that preventive
maintenance increases the profitability of the company.
Properly carried out maintenance results not only in economic gains, but also in an improved
working environment, improved human safety and reduced stress. Energy consumption and
capital costs can also be reduced through proper maintenance.
1.1.3.1 Objective of Implement Maintenance
I. To achieve product quality and customer satisfaction through adjusted and
serviced equipment
II. Maximize useful life of equipment

12. III. Keep equipment safe and prevent safety hazards
IV. Minimize frequency and severity of interruptions
V. Maximize production capacity – through high utilization of facility
VI. Must be consistent with the goals of production (cost, quality, delivery, safety)
VII. Must be comprehensive and include specific responsibilities
1.1.3.2 Advantages of Implementing Maintenance
I. Lower operating costs
II. Faster, more dependable throughput
III. Higher productivity
IV. Improved quality
V. Continuous improvement
VI. Improved capacity
VII. Reduced inventory
a. Advantages of Corrective Maintenance
I. Lower short-term costs.
II. Requires less staff since less work is being done.
b. Advantages of Preventive Maintenance
I. Increased component lifecycle.
II. Reduced asset failure.
III. Some potential energy savings.
IV. Estimated 12-18% cost savings over Corrective Maintenance (CM).
c. Advantages of Predictive Maintenance
I. Increased component lifecycle.
II. Decrease in equipment downtime.
III. Estimated 6% to 15% cost savings over Preventive Maintenance (PM) program
1.2 Explain various types of cost maintenance related.
1.2.1 Introduction
All enterprises and organisations are of course interested in lowering the maintenance costs. The
maintenance cost must be controlled by the people with a knowledge in the field of maintenance.
Many enterprises are operating a cost controlled maintenance management meaning that the
maintenance section is just controlled by the money which is available in the budget. In this case
the consequences for production and other functions will not be taken into consideration due to
the maintenance work.
Comparison of actual maintenance costs against the maintenance budget will be an
inherent part of the cost control system. Should adverse variances occur due, for example, to
severe damage to an item of plant caused by an inefficient operator, the best course of action is

13. for the maintenance engineer to apply for a supplementary addition to his budget. This approach
is to be preferred to the alternative of `delay tactics', where it is hope that savings will be created
in other areas, with the results that at the end of the year total actual costs compare favourably
with the budget costs. This could mean that the required level of maintenance on other machines
has not been completed, to the possible detriment of the machinery's effectiveness in the future.
In these circumstances, it is important that all interested parties appreciate the difficulties
associated with the maintenance function and as a result the engineer/manager and the
management accountant co-operate in developing a system which helps maintenance
management to be more efficient. This principle must apply both at the budget preparation stage
as well as the implementation stage, i.e. in the analysis of variances and consideration of the
various alternative courses of action.
When excessive maintenance occurs due to bad machinery design, it is equally important
that there should be effective feedback of the appropriate information to the manufacturer and/or
designer.
1.2.2 Cost or Result Controlled Maintenance
The cost controlled maintenance is not connected to modern maintenance. According to one of
the maintenance objective is to "keep up planned availability performance to the lowest cost
possible" which means that it is the long term results which must be taken into consideration.
The maintenance cost must be put in relationship with the planned availability performance.
The reason for why maintenance has been treated as a cost controlled activity is often that
technicians have had some difficulties to measure the investments in maintenance in total
economic terms. It is very easy to find the cost of maintenance but it is difficult to see the results.
The maintenance costs can be varying from organisation to organisation and divided into two
categories:-
I. Direct maintenance costs.
a) Personnel cost for those carrying out the maintenance work.
b) Costs for lubricants, paint, gaskets, and other materials which are consumed in
connection with maintenance.
c) Cost of administrative systems connected with maintenance.
d) Costs for premises, equipment and other services used by the maintenance
department.
e) Cost of work carried out by third parties and companies.
f) Costs for rebuilding etc., intended to reduce, simplify or eleminate maintenance.
II. Indirect maintenance cost
Indirect maintenance cost is loss of revenue as a result of interruptions to production
due to inadequate maintenance. For example a shut down in a large process industry
can cost tens of thousands of dollars per hour, twenty-four hours loss of service of a
large ship can lead to losses of hundreds of thousands of dollars.
In results controlled maintenance management it is always the direct maintenance costs
put into relationship to the indirect costs.
Maintenance and its results can be like an iceberg was the biggest part is invisible under
the water level and only a small part is visible above the surface. The visible part is
representing the maintenance costs as the invisible part is representing the costs for
different factors influenced by maintenance.

14. 1.2.3 Four Types of Cost in Maintenance
I. Cost to replace or repair
II. Losses of output
III. Delayed shipment
IV. Scrap and rework
1.3 Describeworkplacesafety.
Defnition
Workplace is the location at or from which an employee ordinarily performs the duties of
his or her position and, in the case of an employee whose duties are of an itinerant nature, the
actual building to which the employee returns to prepare and/or submit reports, etc., and where
other administrative matters pertaining to the employee's employment are conducted.
Workplace safety is essential for providing a safe environment in which employees can work
with minimal risk to their health. On-the-job accidents can cause injuries and death. Preventing
these accidents requires the effort of all employees in the organization. Numerous workplace of
risks exist, including dangers resulting from human errors and mechanical malfunctions. An
organization must use a combination of safety training and safety protocols to prevent as many
employee injuries as possible.
Safe and healthy environment in the workplace benefits everybody. When people feel safe and
are healthy their productivity at work increases. This in turn benefits the company. The number
of work hours lost due to illness and injuries is also decreased in a safe and healthy workplace.
Everyone will be more productive.
Safe and healthy work atmosphere assist in reducing the risk of avoidable problems. It is in the
interest of the company to provide safe and healthy workplace if it needs to avoid dealing with
complaints or lawsuits from its workers arising from injuries while at job.
Companies emphasizing on tidy, organized and safe work environment help boost the individual
and the company‘s morale as a whole. This encourages everyone working there to do their best
and feel good about getting the job done.
Ensuring the safety at workplace does not require huge investment of time or money or other
resources. All you need is to establish the basic framework and pathways to achieve the desired
targets. Everyone working in the company should be made aware of their responsibility to follow
the local policies, provided training with regular updates then the whole environment will
become safe and healthy. When individuals practice the safety at workplace on daily basis it
becomes a second nature. Workers should be encouraged to report near misses which are critical
in developing new strategies and safeguards against possible mishaps. Safe and healthy
workplace leads to confident and productive workers.
Prosperous companies make efforts to ensure their workers safety as these companies have
realized the importance of healthy and happy workers.

15. Working in a clean, healthy environment can have a major effect on your employees. They may
love their job, but on those bad days, a bright and clean workspace can help them through it and
keep them productive. In a dingy or cluttered workspace, bad days and problems seem to fester a
lot longer. A clean workspace can have a major impact on how people feel and behave in the
workplace
1.3.1 Identifythebenefitcleanandsafeworkingenvironment.
A clean workplace improves air quality, and that keeps everyone cutting down on sick days and
absenteeism. Your workers will have more energy and feel more creative. Just the simple task of
cleaning can improve performance and boost business.
When people feel better about their environment, they get along better. If you are having issues
with communication in the workplace and people seem to be bickering with co-workers, try
making the space cleaner. The fresh change may be just what everyone needs to feel better and
try harder to get along with one another in the workplace
Benefits
healthy workers are productive and raise healthy families; thus healthy workers are a key
strategy in overcoming poverty.
workplace health risks are higher in the informal sector and small industries which are key
arenas of action on poverty alleviation, where people can work their way out of poverty.
safe workplaces contribute to sustainable development, which is the key to poverty reduction.
the processes of protecting workers, surrounding communities and the environment for future
generations have important common elements, such as pollution control and exposure
reduction.
much pollution and many environmental exposures that are hazardous to health arise from
industrial processes, that can be beneficially influenced by occupational health and safety
programmes.
occupational safety and health can contribute to improving the employability of workers,
through workplace (re)design, maintenance of a healthy and safe work environment, training
and retraining, assessment of work demands, medical diagnosis, health screening and
assessment of functional capacities.
occupational health is fundamental to public health, for it is increasingly clear that major
diseases (e.g. AIDS, heart disease, cancer) need workplace wellness programmes.
Benefits of promoting a healthy workplace
To the organisation
a well-managed health and safety programme

16. a positive and caring image
improved staff morale
reduced staff turnover
reduced absenteeism
increased productivity
reduced health care/insurance costs
reduced risk of fines and litigation
To the employee
a safe and healthy work environment
enhanced self-esteem
reduced stress
improved morale
increased job satisfaction
increased skills for health protection
improved health
improved sense of well-being
1.3.2 Explaintheimportantof personal protectionequipments.
Introduction
Hazards exist in every workplace in many different forms: sharp edges, falling objects, flying
sparks, chemicals, noise and a myriad of other potentially dangerous situations. The
Occupational Safety and Health Administration (OSHA) requires that employers protect their
employees from workplace hazards that can cause injury.
Controlling a hazard at its source is the best way to protect employees. Depending on the hazard
or workplace conditions, OSHA recommends the use of engineering or work practice controls to
manage or eliminate hazards to the greatest extent possible. For example, building a barrier
between the hazard and the employees is an engineering control; changing the way in which
employees perform their work is a work practice control.
When engineering, work practice and administrative controls are not feasible or do not provide
sufficient protection, employers must provide personal protective equipment (PPE) to their
employees and ensure its use. Personal protective equipment, commonly referred to as "PPE", is
equipment worn to minimize exposure to a variety of hazards. Examples of PPE include such
items as gloves, foot and eye protection, protective hearing devices (earplugs, muffs) hard hats,
respirators and full body suits.
This guide will help both employers and employees do the following:
 Understand the types of PPE.

17.  Know the basics of conducting a "hazard assessment" of the workplace.
 Select appropriate PPE for a variety of circumstances.
 Understand what kind of training is needed in the proper use and care of PPE.
The Requirement for PPE
To ensure the greatest possible protection for employees in the workplace, the cooperative
efforts of both employers and employees will help in establishing and maintaining a safe
and healthful work environment.
In general, employers are responsible for:
 Performing a "hazard assessment" of the workplace to identify and control physical and
health hazards.
 Identifying and providing appropriate PPE for employees.
 Training employees in the use and care of the PPE.
 Maintaining PPE, including replacing worn or damaged PPE.
 Periodically reviewing, updating and evaluating the effectiveness of the PPE program.
In general, employees should:
 Properly wear PPE,
 Attend training sessions on PPE,
 Care for, clean and maintain PPE, and
 Inform a supervisor of the need to repair or replace PPE.
Specific requirements for PPE are presented in many different OSHA standards, published in 29
CFR. Some standards require that employers provide PPE at no cost to the employee while
others simply state that the employer must provide PPE. Appendix A at page 40 lists those
standards that require the employer to provide PPE and those that require the employer to
provide PPE at no cost to the employee.
The Hazard Assessment
A first critical step in developing a comprehensive safety and health program is to identify
physical and health hazards in the workplace. This process is known as a "hazard assessment."
Potential hazards may be physical or health-related and a comprehensive hazard assessment
should identify hazards in both categories. Examples of physical hazards include moving objects,
fluctuating temperatures, high intensity lighting, rolling or pinching objects, electrical
connections and sharp edges. Examples of health hazards include overexposure to harmful dusts,
chemicals or radiation.
The hazard assessment should begin with a walk-through survey of the facility to develop a list
of potential hazards in the following basic hazard categories:

18.  Impact,
 Penetration,
 Compression (roll-over),
 Chemical,
 Heat/cold,
 Harmful dust,
 Light (optical) radiation, and
 Biologic.
In addition to noting the basic layout of the facility and reviewing any history of occupational
illnesses or injuries, things to look for during the walk-through survey include:
 Sources of electricity.
 Sources of motion such as machines or processes where movement may exist that could
result in an impact between personnel and equipment.
 Sources of high temperatures that could result in burns, eye injuries or fire.
 Types of chemicals used in the workplace.
 Sources of harmful dusts.
 Sources of light radiation, such as welding, brazing, cutting, furnaces, heat treating, high
intensity lights, etc.
 The potential for falling or dropping objects.
 Sharp objects that could poke, cut, stab or puncture.
 Biologic hazards such as blood or other potentially infected material.
When the walk-through is complete, the employer should organize and analyze the data so that it
may be efficiently used in determining the proper types of PPE required at the worksite. The
employer should become aware of the different types of PPE available and the levels of
protection offered. It is definitely a good idea to select PPE that will provide a level of protection
greater than the minimum required to protect employees from hazards.
The workplace should be periodically reassessed for any changes in conditions, equipment or
operating procedures that could affect occupational hazards. This periodic reassessment should
also include a review of injury and illness records to spot any trends or areas of concern and
taking appropriate corrective action. The suitability of existing PPE, including an evaluation of
its condition and age, should be included in the reassessment.
Documentation of the hazard assessment is required through a written certification that includes
the following information:
 Identification of the workplace evaluated;
 Name of the person conducting the assessment;
 Date of the assessment; and
 Identification of the document certifying completion of the hazard assessment.
Selecting PPE

19. All PPE clothing and equipment should be of safe design and construction, and should be
maintained in a clean and reliable fashion. Employers should take the fit and comfort of PPE into
consideration when selecting appropriate items for their workplace. PPE that fits well and is
comfortable to wear will encourage employee use of PPE. Most protective devices are available
in multiple sizes and care should be taken to select the proper size for each employee. If several
different types of PPE are worn together, make sure they are compatible. If PPE does not fit
properly, it can make the difference between being safely covered or dangerously exposed. It
may not provide the level of protection desired and may discourage employee use.
OSHA requires that many categories of PPE meet or be equivalent to standards developed by the
American National Standards Institute (ANSI). ANSI has been preparing safety standards since
the 1920s, when the first safety standard was approved to protect the heads and eyes of industrial
workers. Employers who need to provide PPE in the categories listed below must make certain
that any new equipment procured meets the cited ANSI standard. Existing PPE stocks must meet
the ANSI standard in effect at the time of its manufacture or provide protection equivalent to
PPE manufactured to the ANSI criteria. Employers should inform employees who provide their
own PPE of the employer's selection decisions and ensure that any employee-owned PPE used in
the workplace conforms to the employer's criteria, based on the hazard assessment, OSHA
requirements and ANSI standards. OSHA requires PPE to meet the following ANSI standards:
 Eye and Face Protection: ANSI Z87.1-1989 (USA Standard for Occupational and
Educational Eye and Face Protection).
 Head Protection: ANSI Z89.1-1986.
 Foot Protection: ANSI Z41.1-1991.
For hand protection, there is no ANSI standard for gloves but OSHA recommends that selection
be based upon the tasks to be performed and the performance and construction characteristics of
the glove material. For protection against chemicals, glove selection must be based on the
chemicals encountered, the chemical resistance and the physical properties of the glove material.
Training Employees in the Proper Use of PPE
Employers are required to train each employee who must use PPE. Employees must be trained to
know at least the following:
 When PPE is necessary.
 What PPE is necessary.
 How to properly put on, take off, adjust and wear the PPE.
 The limitations of the PPE.
 Proper care, maintenance, useful life and disposal of PPE.
Employers should make sure that each employee demonstrates an understanding of the PPE
training as well as the ability to properly wear and use PPE before they are allowed to perform
work requiring the use of the PPE. If an employer believes that a previously trained employee is
not demonstrating the proper understanding and skill level in the use of PPE, that employee
should receive retraining. Other situations that require additional or retraining of employees

20. include the following circumstances: changes in the workplace or in the type of required PPE
that make prior training obsolete.
The employer must document the training of each employee required to wear or use PPE by
preparing a certification containing the name of each employee trained, the date of training and a
clear identification of the subject of the certification.
Eye and Face Protection
Employees can be exposed to a large number of hazards that pose danger to their eyes and face.
OSHA requires employers to ensure that employees have appropriate eye or face protection if
they are exposed to eye or face hazards from flying particles, molten metal, liquid chemicals,
acids or caustic liquids, chemical gases or vapors, potentially infected material or potentially
harmful light radiation.
Many occupational eye injuries occur because workers are not wearing any eye protection while
others result from wearing improper or poorly fitting eye protection. Employers must be sure that
their employees wear appropriate eye and face protection and that the selected form of protection
is appropriate to the work being performed and properly fits each worker exposed to the hazard.
Prescription Lenses
Everyday use of prescription corrective lenses will not provide adequate protection against most
occupational eye and face hazards, so employers must make sure that employees with corrective
lenses either wear eye protection that incorporates the prescription into the design or wear
additional eye protection over their prescription lenses. It is important to ensure that the
protective eyewear does not disturb the proper positioning of the prescription lenses so that the
employee's vision will not be inhibited or limited. Also, employees who wear contact lenses
must wear eye or face PPE when working in hazardous conditions.
Eye Protection for Exposed Workers
OSHA suggests that eye protection be routinely considered for use by carpenters, electricians,
machinists, mechanics, millwrights, plumbers and pipefitters, sheetmetal workers and tinsmiths,
assemblers, sanders, grinding machine operators, sawyers, welders, laborers, chemical process
operators and handlers, and timber cutting and logging workers. Employers of workers in other
job categories should decide whether there is a need for eye and face PPE through a hazard
assessment.
Examples of potential eye or face injuries include:
 Dust, dirt, metal or wood chips entering the eye from activities such as chipping,
grinding, sawing, hammering, the use of power tools or even strong wind forces.
 Chemical splashes from corrosive substances, hot liquids, solvents or other hazardous
solutions.
 Objects swinging into the eye or face, such as tree limbs, chains, tools or ropes.
 Radiant energy from welding, harmful rays from the use of lasers or other radiant light
(as well as heat, glare, sparks, splash and flying particles).

21. Types of Eye Protection
Selecting the most suitable eye and face protection for employees should take into consideration
the following elements:
 Ability to protect against specific workplace hazards.
 Should fit properly and be reasonably comfortable to wear.
 Should provide unrestricted vision and movement.
 Should be durable and cleanable.
 Should allow unrestricted functioning of any other required PPE.
The eye and face protection selected for employee use must clearly identify the manufacturer.
Any new eye and face protective devices must comply with ANSI Z87.1-1989 or be at least as
effective as this standard requires. Any equipment purchased before this requirement took effect
on July 5, 1994, must comply with the earlier ANSI Standard (ANSI Z87.1-1968) or be shown to
be equally effective.
An employer may choose to provide one pair of protective eyewear for each position rather than
individual eyewear for each employee. If this is done, the employer must make sure that
employees disinfect shared protective eyewear after each use. Protective eyewear with corrective
lenses may only be used by the employee for whom the corrective prescription was issued and
may not be shared among employees.
Some of the most common types of eye and face protection include the following:
 Safety spectacles. These protective eyeglasses have safety frames constructed of metal or
plastic and impact-resistant lenses. Side shields are available on some models.
 Goggles. These are tight-fitting eye protection that completely cover the eyes, eye
sockets and the facial area immediately surrounding the eyes and provide protection from
impact, dust and splashes. Some goggles will fit over corrective lenses.
 Welding shields. Constructed of vulcanized fiber or fiberglass and fitted with a filtered
lens, welding shields protect eyes from burns caused by infrared or intense radiant light;
they also protect both the eyes and face from flying sparks, metal spatter and slag chips
produced during welding, brazing, soldering and cutting operations. OSHA requires filter
lenses to have a shade number appropriate to protect against the specific hazards of the
work being performed in order to protect against harmful light radiation.
 Laser safety goggles. These specialty goggles protect against intense concentrations of
light produced by lasers. The type of laser safety goggles an employer chooses will
depend upon the equipment and operating conditions in the workplace.
 Face shields. These transparent sheets of plastic extend from the eyebrows to below the
chin and across the entire width of the employee's head. Some are polarized for glare
protection. Face shields protect against nuisance dusts and potential splashes or sprays of
hazardous liquids but will not provide adequate protection against impact hazards. Face
shields used in combination with goggles or safety spectacles will provide additional
protection against impact hazards.

22. Each type of protective eyewear is designed to protect against specific hazards. Employers can
identify the specific workplace hazards that threaten employees' eyes and faces by completing a
hazard assessment as outlined in the earlier section.
Welding Operations
The intense light associated with welding operations can cause serious and sometimes permanent
eye damage if operators do not wear proper eye protection. The intensity of light or radiant
energy produced by welding, cutting or brazing operations varies according to a number of
factors including the task producing the light, the electrode size and the arc current. The
following table shows the minimum protective shades for a variety of welding, cutting and
brazing operations in general industry and in the shipbuilding industry.
Table 1
Filter Lenses for Protection Against Radiant Energy
Operations Electrode size in 1/32" (0.8mm) Arc current Minimum* protective shade
Shielded metal arc welding < 3
3 - 5
5 - 8
> 8
< 60
60 - 160
160 - 250
250 - 550
7
8
10
11
Gas metal arc welding
and flux cored
arc welding
< 60
60 - 160
160 - 250
250 - 500
7
10
10
10
Gas tungsten
arc welding
< 50
50 - 150
150 - 500
8
8
10
Air carbon (light) < 500 10
Arc cutting (heavy) 500 - 1,000 11
Plasma arc welding < 20
20 - 100
100 - 400
400 - 800
6
8
10
11
Plasma arc cutting (light)**
(medium)**
(heavy)**
< 300
300 - 400
400 - 800
8
9
10
Torch brazing 3
Torch soldering 2
Carbon arc welding 14
Table 2
Filter Lenses for Protection Against Radiant Energy
Operations Plate thickness inches Plate thickness mm Minimum* protective shade

23. Gas welding:
Light
< 1/8 < 3.2 4
Gas welding:
Medium
1/8 - 1/2 3.2 - 12.7 5
Gas welding:
Heavy
> 1/2 > 12.7 6
Oxygen cutting:
Light
< 1 < 25 3
Oxygen cutting: Medium 1 - 6 25 - 150 4
Oxygen cutting:
Heavy
> 6 > 150 5
Source: 29 CFR 1910.133(a)(5).
* As a rule of thumb, start with a shade that is too dark to see the weld zone. Then go to a lighter
shade which gives sufficient view of the weld zone without going below the minimum. In
oxyfuel gas welding or cutting where the torch produces a high yellow light, it is desirable to use
a filter lens that absorbs the yellow or sodium line in the visible light of the (spectrum) operation.
** These values apply where the actual arc is clearly seen. Experience has shown that lighter
filters may be used when the arc is hidden by the workpiece.
The construction industry has separate requirements for filter lens protective levels for specific
types of welding operations, as indicated in the table below:
Laser Operations
Laser light radiation can be extremely dangerous to the unprotected eye and direct or reflected
beams can cause permanent eye damage. Laser retinal burns can be painless, so it is essential that
all personnel in or around laser operations wear appropriate eye protection.
Laser safety goggles should protect for the specific wavelength of the laser and must be of
sufficient optical density for the energy involved. Safety goggles intended for use with laser
beams must be labeled with the laser wavelengths for which they are intended to be used, the
optical density of those wavelengths and the visible light transmission.
The table below lists maximum power or energy densities and appropriate protection levels for
optical densities 5 through 8.
Table 3
Selecting Laser Safety Glass
Intensity, CW maximum power density
(watts/cm2
)
Attenuation
Optical density
(O.D.)
Attenuation
factor
10-2 5 105

24. 10-1 6 106
1.0 7 107
10.0 8 108
Source: 29 CFR 1926.102(b)(2).
Head Protection
Protecting employees from potential head injuries is a key element of any safety program. A
head injury can impair an employee for life or it can be fatal. Wearing a safety helmet or hard hat
is one of the easiest ways to protect an employee's head from injury. Hard hats can protect
employees from impact and penetration hazards as well as from electrical shock and burn
hazards.
Employers must ensure that their employees wear head protection if any of the following apply:
 Objects might fall from above and strike them on the head;
 They might bump their heads against fixed objects, such as exposed pipes or beams; or
 There is a possibility of accidental head contact with electrical hazards.
Some examples of occupations in which employees should be required to wear head protection
include construction workers, carpenters, electricians, linemen, plumbers and pipefitters, timber
and log cutters, welders, among many others. Whenever there is a danger of objects falling from
above, such as working below others who are using tools or working under a conveyor belt, head
protection must be worn. Hard hats must be worn with the bill forward to protect employees
properly.
In general, protective helmets or hard hats should do the following:
 Resist penetration by objects.
 Absorb the shock of a blow.
 Be water-resistant and slow burning.
 Have clear instructions explaining proper adjustment and replacement of the suspension
and headband.
Hard hats must have a hard outer shell and a shock-absorbing lining that incorporates a headband
and straps that suspend the shell from 1 to 1 1/4 inches (2.54 cm to 3.18 cm) away from the head.
This type of design provides shock absorption during an impact and ventilation during normal
wear.
Protective headgear must meet ANSI Standard Z89.1-1986 (Protective Headgear for Industrial
Workers) or provide an equivalent level of protection. Helmets purchased before July 5, 1994
must comply with the earlier ANSI Standard (Z89.1-1969) or provide equivalent protection.
Types of Hard Hats

25. There are many types of hard hats available in the marketplace today. In addition to selecting
protective headgear that meets ANSI standard requirements, employers should ensure that
employees wear hard hats that provide appropriate protection against potential workplace
hazards. It is important for employers to understand all potential hazards when making this
selection, including electrical hazards. This can be done through a comprehensive hazard
analysis and an awareness of the different types of protective headgear available.
Hard hats are divided into three industrial classes:
 Class A hard hats provide impact and penetration resistance along with limited voltage
protection (up to 2,200 volts).
 Class B hard hats provide the highest level of protection against electrical hazards, with
high-voltage shock and burn protection (up to 20,000 volts). They also provide protection
from impact and penetration hazards by flying/falling objects.
 Class C hard hats provide lightweight comfort and impact protection but offer no
protection from electrical hazards.
Another class of protective headgear on the market is called a ―bump hat," designed for use in
areas with low head clearance. They are recommended for areas where protection is needed from
head bumps and lacerations. These are not designed to protect against falling or flying objects
and are not ANSI approved. It is essential to check the type of hard hat employees are using to
ensure that the equipment provides appropriate protection. Each hat should bear a label inside the
shell that lists the manufacturer, the ANSI designation and the class of the hat.
Size and Care Considerations
Head protection that is either too large or too small is inappropriate for use, even if it meets all
other requirements. Protective headgear must fit appropriately on the body and for the head size
of each individual. Most protective headgear comes in a variety of sizes with adjustable
headbands to ensure a proper fit (many adjust in 1/8-inch increments). A proper fit should allow
sufficient clearance between the shell and the suspension system for ventilation and distribution
of an impact. The hat should not bind, slip, fall off or irritate the skin.
Some protective headgear allows for the use of various accessories to help employees deal with
changing environmental conditions, such as slots for earmuffs, safety glasses, face shields and
mounted lights. Optional brims may provide additional protection from the sun and some hats
have channels that guide rainwater away from the face. Protective headgear accessories must not
compromise the safety elements of the equipment.
Periodic cleaning and inspection will extend the useful life of protective headgear. A daily
inspection of the hard hat shell, suspension system and other accessories for holes, cracks, tears
or other damage that might compromise the protective value of the hat is essential. Paints, paint
thinners and some cleaning agents can weaken the shells of hard hats and may eliminate
electrical resistance. Consult the helmet manufacturer for information on the effects of paint and
cleaning materials on their hard hats. Never drill holes, paint or apply labels to protective
headgear as this may reduce the integrity of the protection. Do not store protective headgear in
direct sunlight, such as on the rear window shelf of a car, since sunlight and extreme heat can

26. damage them.
Hard hats with any of the following defects should be removed from service and replaced:
 Perforation, cracking, or deformity of the brim or shell;
 Indication of exposure of the brim or shell to heat, chemicals or ultraviolet light and other
radiation (in addition to a loss of surface gloss, such signs include chalking or flaking).
Always replace a hard hat if it sustains an impact, even if damage is not noticeable. Suspension
systems are offered as replacement parts and should be replaced when damaged or when
excessive wear is noticed. It is not necessary to replace the entire hard hat when deterioration or
tears of the suspension systems are noticed.
Foot and Leg Protection
Employees who face possible foot or leg injuries from falling or rolling objects or from crushing
or penetrating materials should
wear protective footwear. Also, employees whose work involves exposure to hot substances or
corrosive or poisonous materials must have protective gear to cover exposed body parts,
including legs and feet. If an employee's feet may be exposed to electrical hazards, non-
conductive footwear should be worn. On the other hand, workplace exposure to static electricity
may necessitate the use of conductive footwear.
Examples of situations in which an employee should wear foot and/or leg protection include:
 When heavy objects such as barrels or tools might roll onto or fall on the employee's feet;
Working with sharp objects such as nails or spikes that could pierce the soles or uppers of
ordinary shoes;
Exposure to molten metal that might splash on feet or legs;
Working on or around hot, wet or slippery surfaces; and
 Working when electrical hazards are present.
Safety footwear must meet ANSI minimum compression and impact performance standards in
ANSI Z41-1991 (American National Standard for Personal Protection-Protective Footwear) or
provide equivalent protection. Footwear purchased before July 5, 1994, must meet or provide
equivalent protection to the earlier ANSI Standard (ANSI Z41.1-1967). All ANSI approved
footwear has a protective toe and offers impact and compression protection. But the type and
amount of protection is not always the same. Different footwear protects in different ways.
Check the product's labeling or consult the manufacturer to make sure the footwear will protect
the user from the hazards they face.
Foot and leg protection choices include the following:
 Leggings protect the lower legs and feet from heat hazards such as molten metal or
welding sparks. Safety snaps allow leggings to be removed quickly.

27.  Metatarsal guards protect the instep area from impact and compression. Made of
aluminum, steel, fiber or plastic, these guards may be strapped to the outside of shoes.
 Toe guards fit over the toes of regular shoes to protect the toes from impact and
compression hazards. They may be made of steel, aluminum or plastic.
 Combination foot and shin guards protect the lower legs and feet, and may be used in
combination with toe guards when greater protection is needed.
 Safety shoes have impact-resistant toes and heat-resistant soles that protect the feet
against hot work surfaces common in roofing, paving and hot metal industries. The metal
insoles of some safety shoes protect against puncture wounds. Safety shoes may also be
designed to be electrically conductive to prevent the buildup of static electricity in areas
with the potential for explosive atmospheres or nonconductive to protect workers from
workplace electrical hazards.
Special Purpose Shoes
Electrically conductive shoes provide protection against the buildup of static electricity.
Employees working in explosive and hazardous locations such as explosives manufacturing
facilities or grain elevators must wear conductive shoes to reduce the risk of static electricity
buildup on the body that could produce a spark and cause an explosion or fire. Foot powder
should not be used in conjunction with protective conductive footwear because it provides
insulation, reducing the conductive ability of the shoes. Silk, wool and nylon socks can produce
static electricity and should not be worn with conductive footwear. Conductive shoes must be
removed when the task requiring their use is completed. Note: Employees exposed to electrical
hazards must never wear conductive shoes.
Electrical hazard, safety-toe shoes are nonconductive and will prevent the wearers' feet from
completing an electrical circuit to the ground. These shoes can protect against open circuits of up
to 600 volts in dry conditions and should be used in conjunction with other insulating equipment
and additional precautions to reduce the risk of a worker becoming a path for hazardous
electrical energy. The insulating protection of electrical hazard, safety-toe shoes may be
compromised if the shoes become wet, the soles are worn through, metal particles become
embedded in the sole or heel, or workers touch conductive, grounded items. Note:
Nonconductive footwear must not be used in explosive or hazardous locations.
Foundry Shoes
In addition to insulating the feet from the extreme heat of molten metal, foundry shoes keep hot
metal from lodging in shoe eyelets, tongues or other shoe parts. These snug-fitting leather or
leather-substitute shoes have leather or rubber soles and rubber heels. All foundry shoes must
have built-in safety toes.
Care of Protective Footwear
As with all protective equipment, safety footwear should be inspected prior to each use. Shoes
and leggings should be checked for wear and tear at reasonable intervals. This includes looking
for cracks or holes, separation of materials, broken buckles or laces. The soles of shoes should be
checked for pieces of metal or other embedded items that could present electrical or tripping

28. hazards. Employees should follow the manufacturers' recommendations for cleaning and
maintenance of protective footwear.
Hand and Arm Protection
If a workplace hazard assessment reveals that employees face potential injury to hands and arms
that cannot be eliminated through engineering and work practice controls, employers must
ensure that employees wear appropriate protection. Potential hazards include skin absorption of
harmful substances, chemical or thermal burns, electrical dangers, bruises, abrasions, cuts,
punctures, fractures and amputations. Protective equipment includes gloves, finger guards and
arm coverings or elbow-length gloves.
Employers should explore all possible engineering and work practice controls to eliminate
hazards and use PPE to provide additional protection against hazards that cannot be completely
eliminated through other means. For example, machine guards may eliminate a hazard. Installing
a barrier to prevent workers from placing their hands at the point of contact between a table saw
blade and the item being cut is another method.
Types of Protective Gloves
There are many types of gloves available today to protect against a wide variety of hazards. The
nature of the hazard and the operation involved will affect the selection of gloves. The variety of
potential occupational hand injuries makes selecting the right pair of gloves challenging. It is
essential that employees use gloves specifically designed for the hazards and tasks found in their
workplace because gloves designed for one function may not protect against a different function
even though they may appear to be an appropriate protective device.
The following are examples of some factors that may influence the selection of protective gloves
for a workplace.
 Type of chemicals handled.
 Nature of contact (total immersion, splash, etc.).
 Duration of contact.
 Area requiring protection (hand only, forearm, arm).
 Grip requirements (dry, wet, oily).
 Thermal protection.
 Size and comfort.
 Abrasion/resistance requirements.
 Gloves made from a wide variety of materials are designed for many types of workplace
hazards. In general, gloves fall into four groups:
 Gloves made of leather, canvas or metal mesh;
 Fabric and coated fabric gloves;
 Chemical- and liquid-resistant gloves;

29.  Insulating rubber gloves (See 29 CFR 1910.137 and the following section on electrical
protective equipment for detailed requirements on the selection, use and care of
insulating rubber gloves).
Leather, Canvas or Metal Mesh Gloves
Sturdy gloves made from metal mesh, leather or canvas provide protection against cuts and
burns. Leather or canvass gloves also protect against sustained heat.
 Leather gloves protect against sparks, moderate heat, blows, chips and rough objects.
 Aluminized gloves provide reflective and insulating protection against heat and require
an insert made of synthetic materials to protect against heat and cold.
 Aramid fiber gloves protect against heat and cold, are cut - and abrasive - resistant and
wear well.
 Synthetic gloves of various materials offer protection against heat and cold, are cut - and
abrasive - resistant and may withstand some diluted acids. These materials do not stand
up against alkalis and solvents.
Fabric and Coated Fabric Gloves
Fabric and coated fabric gloves are made of cotton or other fabric to provide varying degrees of
protection.
 Fabric gloves protect against dirt, slivers, chafing and abrasions. They do not provide
sufficient protection for use with rough, sharp or heavy materials. Adding a plastic
coating will strengthen some fabric gloves.
 Coated fabric gloves are normally made from cotton flannel with napping on one side.
By coating the unnapped side with plastic, fabric gloves are transformed into general-
purpose hand protection offering slip-resistant qualities. These gloves are used for tasks
ranging from handling bricks and wire to chemical laboratory containers. When selecting
gloves to protect against chemical exposure hazards, always check with the manufacturer
or review the manufacturer's product literature to determine the gloves' effectiveness
against specific workplace chemicals and conditions.
Chemical - and Liquid - Resistant Gloves
Chemical-resistant gloves are made with different kinds of rubber: natural, butyl, neoprene,
nitrile and fluorocarbon (viton); or various kinds of plastic: polyvinyl chloride (PVC), polyvinyl
alcohol and polyethylene. These materials can be blended or laminated for better performance.
As a general rule, the thicker the glove material, the greater the chemical resistance but thick
gloves may impair grip and dexterity, having a negative impact on safety.
Some examples of chemical-resistant gloves include:
 Butyl gloves are made of a synthetic rubber and protect against a wide variety of
chemicals, such as peroxide, rocket fuels, highly corrosive acids (nitric acid, sulfuric
acid, hydrofluoric acid and red-fuming nitric acid), strong bases, alcohols, aldehydes,
ketones, esters and nitrocompounds. Butyl gloves also resist oxidation, ozone corrosion
and abrasion, and remain flexible at low temperatures. Butyl rubber does not perform
well with aliphatic and aromatic hydrocarbons and halogenated solvents.

30.  Natural (latex) rubber gloves are comfortable to wear, which makes them a popular
general-purpose glove. They feature outstanding tensile strength, elasticity and
temperature resistance. In addition to resisting abrasions caused by grinding and
polishing, these gloves protect workers' hands from most water solutions of acids, alkalis,
salts and ketones. Latex gloves have caused allergic reactions in some individuals and
may not be appropriate for all employees. Hypoallergenic gloves, glove liners and
powderless gloves are possible alternatives for workers who are allergic to latex gloves.
 Neoprene gloves are made of synthetic rubber and offer good pliability, finger dexterity,
high density and tear resistance. They protect against hydraulic fluids, gasoline, alcohols,
organic acids and alkalis. They generally have chemical and wear resistance properties
superior to those made of natural rubber.
 Nitrile gloves are made of a copolymer and provide protection from chlorinated solvents
such as trichloroethylene and perchloroethylene. Although intended for jobs requiring
dexterity and sensitivity, nitrile gloves stand up to heavy use even after prolonged
exposure to substances that cause other gloves to deteriorate. They offer protection when
working with oils, greases, acids, caustics and alcohols but are generally not
recommended for use with strong oxidizing agents, aromatic solvents, ketones and
acetates.
Care of Protective Gloves
Protective gloves should be inspected before each use to ensure that they are not torn, punctured
or made ineffective in any way. A visual inspection will help detect cuts or tears but a more
thorough inspection by filling the gloves with water and tightly rolling the cuff towards the
fingers will help reveal any pinhole leaks. Gloves that are discolored or stiff may also indicate
deficiencies caused by excessive use or degradation from chemical exposure.
Any gloves with impaired protective ability should be discarded and replaced. Reuse of
chemical-resistant gloves should be evaluated carefully, taking into consideration the absorptive
qualities of the gloves. A decision to reuse chemically-exposed gloves should take into
consideration the toxicity of the chemicals involved and factors such as duration of exposure,
storage and temperature.
Body Protection
Employees who face possible bodily injury of any kind that cannot be eliminated through
engineering, work practice or administrative controls, must wear appropriate body protection
while performing their jobs. In addition to cuts and radiation, the following are examples of
workplace hazards that could cause bodily injury:
 Temperature extremes;
 Hot splashes from molten metals and other hot liquids;
 Potential impacts from tools, machinery and materials;
 Hazardous chemicals.

31. There are many varieties of protective clothing available for specific hazards. Employers are
required to ensure that their employees wear personal protective equipment only for the parts of
the body exposed to possible injury. Examples of body protection include laboratory coats,
coveralls, vests, jackets, aprons, surgical gowns and full body suits.
If a hazard assessment indicates a need for full body protection against toxic substances or
harmful physical agents, the clothing should be carefully inspected before each use, it must fit
each worker properly and it must function properly and for the purpose for which it is intended.
Protective clothing comes in a variety of materials, each effective against particular hazards,
such as:
 Paper-like fiber used for disposable suits provide protection against dust and splashes.
 Treated wool and cotton adapts well to changing temperatures, is comfortable, and fire-
resistant and protects against dust, abrasions and rough and irritating surfaces.
 Duck is a closely woven cotton fabric that protects against cuts and bruises when
handling heavy, sharp or rough materials.
 Leather is often used to protect against dry heat and flames.
 Rubber, rubberized fabrics, neoprene and plastics protect against certain chemicals
and physical hazards. When chemical or physical hazards are present, check with the
clothing manufacturer to ensure that the material selected will provide protection against
the specific hazard.
Hearing Protection
Determining the need to provide hearing protection for employees can be challenging. Employee
exposure to excessive noise depends upon a number of factors, including:
 The loudness of the noise as measured in decibels (dB).
 The duration of each employee's exposure to the noise.
 Whether employees move between work areas with different noise levels.
 Whether noise is generated from one or multiple sources.
Generally, the louder the noise, the shorter the exposure time before hearing protection is
required. For instance, employees may be exposed to a noise level of 90 dB for 8 hours per day
(unless they experience a Standard Threshold Shift) before hearing protection is required. On the
other hand, if the noise level reaches 115 dB hearing protection is required if the anticipated
exposure exceeds 15 minutes.
For a more detailed discussion of the requirements for a comprehensive hearing conservation
program, see OSHA Publication 3074 (2002), ―Hearing Conservation" or refer to the OSHA
standard at 29 CFR 1910.95, Occupational Noise Exposure, section (c).
Table 5, below, shows the permissible noise exposures that require hearing protection for
employees exposed to occupational noise at specific decibel levels for specific time periods.
Noises are considered continuous if the interval between occurrences of the maximum noise

32. level is one second or less. Noises not meeting this definition are considered impact or impulse
noises (loud momentary explosions of sound) and exposures to this type of noise must not
exceed 140 dB. Examples of situations or tools that may result in impact or impulse noises are
powder-actuated nail guns, a punch press or drop hammers.
Table 3
Permissible Noise Exposures 1/4 or less 115
Duration per day,
in hours
Sound level in dB*
8 90
6 92
4 95
3 97
2 100
11/2
5
102
1 105
1/2 110
1/4 or less 11
*When measured on the A scale of a standard sound level meter at slow response.
Source: 29 CFR 1910.95,Table G-16.
If engineering and work practice controls do not lower employee exposure to workplace noise to
acceptable levels, employees must wear appropriate hearing protection. It is important to
understand that hearing protectors reduce only the amount of noise that gets through to the ears.
The amount of this reduction is referred to as attenuation, which differs according to the type of
hearing protection used and how well it fits. Hearing protectors worn by employees must reduce
an employee's noise exposure to within the acceptable limits noted in Table 5. Refer to Appendix
B of 29 CFR 1910.95, Occupational Noise Exposure, for detailed information on methods to
estimate the attenuation effectiveness of hearing protectors based on the device's noise reduction
rating (NRR). Manufacturers of hearing protection devices must display the device's NRR on the
product packaging. If employees are exposed to occupational noise at or above 85 dB averaged
over an eight-hour period, the employer is required to institute a hearing conservation program
that includes regular testing of employees' hearing by qualified professionals. Refer to 29 CFR
1910.95(c) for a description of the requirements for a hearing conservation program.
Some types of hearing protection include:
 Single-use earplugs are made of waxed cotton, foam, silicone rubber or fiberglass wool.
They are self-forming and, when properly inserted, they work as well as most molded
earplugs.
 Pre-formed or molded earplugs must be individually fitted by a professional and can be
disposable or reusable. Reusable plugs should be cleaned after each use.
 Earmuffs require a perfect seal around the ear. Glasses, facial hair, long hair or facial
movements such as chewing may reduce the protective value of earmuffs.

33. 1.3.3 Use lockout and tag-out when needed.
Definition of Lockout/Tagout
Lockout is a technique used to prevent equipment from being accidentally started and
stored energy from being released while an associated machine or piece of equipment is being
serviced. A padlock or any other appropriate mechanical device that physically prevents the
transmission or release of energy is placed on the energy-isolating device that should be in the
off or closed position.
Energy-isolating devices can be:
• Disconnect switches
• Circuit breakers
• Valve handles
• Blocks
• Blind flanges
A tag also will be placed together with the locking device, to explain why the equipment is
locked, by whom and for how long. The use of only tags, without locks, is acceptable if
additional measures to protect equipment are put in place. For example:
• Removal of the circuit-isolating element
• Removal the valve handle
• Blockage of a controlling device
The ultimate goal of lockout/tagout is to protect the safety and health of employees. Secondary is
the protection of equipment from damage.
Types of Lockout Devices:
• Disconnect switches
• Slide gates
• Valves (ball, gate, etc.)
Colour Code for Locks and Tags:
Locks:
• Blue locks - equipment locks - used to protect equipment.
• Red locks - used for Personal Protection.
• Green locks - given to contractors to use on equipment.

34. • Orange Locks - control a group lockout.
Locks out many pieces of equipment with only one locking device.
Tags:
• Red tags with Red locks - used for personal protection of employees.
• Red tags with Green locks – used for contractor protection.
• Yellow tags with Blue locks – used for protection of equipment.
• Yellow tags without a lock – non-energized equipment out of service.
The tag will tell what is wrong with the equipment.
The 5 Main Causes of Fatal Lockout/Tagout Injuries:
1. Failure to stop equipment
2. Failure to disconnect from power source
3. Failure to dissipate (bleed, neutralize) residual energy
4. Accidental restarting of equipment
5. Failure to clear work areas before restarting
Lockout Procedure:
1. Preparation for Shutdown – study the equipment and the source(s) of energy before
tagging/locking it. Alert the operator (s) that power is going to be disconnected.
2. Equipment Shutdown
3. Equipment Isolation – find and isolate every form of energy that the machine uses.
4. Application of Lockout Devices – apply lock and/or tags to all energy isolating equipment.
Anything that might restore the flow of energy to the work area must be locked out.
5. Control of Stored Energy – after locking out/tagging out the equipment, the stored energy
must be controlled by:
i. Relieving any residual energy
ii. Waiting until moving parts stop
iii. Relieving trapped pressure
iv. Installing ground wires to discharge electrical capacitors
v. Blocking or supporting elevated equipment
6. Verify Equipment Isolation – before starting the work, check once more if all the equipment is
locked out/tagged out and free from stored energy.

35. Removal of Lockout
1. Restore Serviced Equipment:
• Remove all tools
• Ensure all equipment components are securely in place
• Re-attach all safety features (guards)
• Close serviced equipment
• Ensure equipment is safe to operate
2. Notify Personnel – that lockout/tagout devices are going to be removed
3. Remove lockout/tagout devices – only the person who placed each lockout/tagout device is
authorized to remove them.
Reactivating Equipment
1. Wait until the last lockout/tagout device is removed
2. Gather all workers involved in the operation in a safe place, to ensure nobody is still working
in the area
3. Tell workers the equipment is going to be re-energized
4. Re-energize the equipment
Follow Up:
1. Report any problems found with the lockout/tagout procedure to your supervisor
2. Share this information with workers who were involved in the operation
1.3.4 Identifyalltheorganizationthatgovernsthesafetyof
hazardousmaterial.
A series of regulations have been introduced under OSHA 1994. The emphasis
of these regulations has been on establishing mechanism to implement OSH in
workplaces. Workplaces with five or more workers are required to formulate a Safety
and Health Policy. The Safety and Health Committee Regulations 1996 requires
establishments with 40 workers and above to establish a safety and health committee.
The committee is required to meet at least once in every three months, with the functions
to identify hazards at the workplace, institute control measures, investigate incident and
conducting audit.
In terms of representation in the committee, workplace with less than 100
workers will need to have at least two representatives each for workers and management
respectively. However, workplaces with more than 100 workers will need to have a
minimum of four representatives each for workers and management.

36. The Safety and Health Officer Regulations provide for specific industries to have
a Safety and Health Officer (SHO). A SHO is an individual who has attended training in
National Institute of Occupational Safety and Health (NIOSH) or other accredited
training bodies and has passed the examination conducted by NIOSH and registered
with Department of Safety and Health (DOSH).
Accident Investigation
Purpose:
• To establish the causes of the accidents
• To establish proper control measures so that future accident can be prevented
• To records all facts about the accident for various reasons (compensation, claims etc.)
• To analyse trend and cost for long term planning
Who Should Investigate (Under The Act)
• Supervisor
• Safety and Health Officer
• Safety and Health Committee Members
• Special Team
Responsibilities for Safety and Health
The Occupational Safety and Health Act, 1994 (Malaysia) places a general duty of care
upon managers to ensure, as far as is practicable, that their employees are not exposed to
hazards. The same Act also places on employees the responsibility to ensure that they do
not expose themselves or others to hazards. The University acknowledges that the Vice
Chancellor is ultimately accountable for the safety and health of its staff, students, visitors,
contractors and persons under labour hire agreements, and is committed to providing and
maintaining a safe and healthy workplace.

37. Responsibilities of Managers and Supervisors
Managers and supervisors have an overall responsibility to ensure that employees are not
exposed to hazards at work. The Act bestows a number of specific duties on managers.
1. Provide and maintain workplaces, equipment and systems of work that do not expose
employees to hazards.
To achieve this, a manager needs to:
• determine safe methods of work and ensure staff perform their work in a safe manner
• develop and maintain safety policies and guidelines on safe work procedures
• ensure that the existing working environment, equipment, processes and work practices
do not expose staff to hazards
• assess the risks associated with any intended changes to staff duties and work practices
and make practicable changes to improve safety and health in the workplace
• assess items before purchase or lease to ensure staff will not be exposed to hazards
• identify hazards in the work area, make assessments of risk and apply practicable
control measures
• investigate incidents to find ways of preventing them recurring
• budget for the provision and maintenance of the working environment and appropriate
equipment to enable work to be carried out safely.
2. Provide information, instruction, training and supervision so employees can perform
their work safely.
To achieve this, a manager needs to:
• establish and maintain information on managing the known hazards in the work
area, including:
(i) policies and safe work procedures
(ii) Malaysian Standards, Codes of Practice and Guidance Notes
(iii) Material Safety Data Sheets (MSDS) on hazardous substances
• make sure staff are familiar with appropriate safety policies, guidelines, standards,
codes of practice and MSDSs that relate to their work
• provide relevant training to staff on safety and health in the workplace
• maintain records of what training has been provided, when and to whom
• ensure staff are supported and supervised in performing their work safely
• promote safe work practices and safety and health in the workplace.
3. Consult and cooperate with employees and Safety and Health Representatives
(SHRs).
To achieve this, a manager needs to:
• know and support the SHR for their work area
• consult employees and SHRs about proposed changes to the working environment.
• make decisions about how to resolve safety and health issues following consultation
• inform the SHR of identified hazards and incidents in their work area

38. • work with the SHR to identify and investigate hazards and incidents and develop
appropriate control measures.
4. Provide adequate protective clothing and equipment where hazards cannot be avoided.
To achieve this, a manager needs to:
• know what protective clothing and equipment is required for the hazards in their
work area
• make sure the appropriate protective clothing and equipment is available, and there
are facilities for cleaning, maintenance and storage
• provide instruction and training on how to use and maintain the protective clothing
and equipment correctly
• ensure that employees, students and visitors under their control correctly use protective
clothing and equipment provided.
Introduction
Hand Tools - Tools that are manually operated and powered by human force such as screw
drivers, pliers, wrenches, and cutting shears, etc.
Portable Power Tools - Power tools that are hand held, manually operated, and powered by
electricity, air, gasoline, diesel, or explosion, such as circular saws, sanders, drills, reciprocating
saws, air wrenches, air grinders, air fasteners, chainsaws, ―Ramset guns‖ etc.
Different types of power tools source:
 Electric
 Pneumatic
 Liquid fuel
 Hydraulic
 Powder-actuated
Each employer shall be responsible for the safe condition of tools and equipment used by
employees, including tools and equipment which may be furnished by employees. Employers
shall not issue or permit the use of unsafe hand tools. Wrenches, including adjustable, pipe, end,
and socket wrenches shall not be used when jaws are sprung to the point that slippage occurs.
Impact tools, such as drift pins, wedges, and chisels, shall be kept free of mushroomed heads.
The wooden handles of tools shall be kept free of splinters or cracks and shall be kept tight in the
tool.
Employees who use hand and power tools and who are exposed to the hazards of falling, flying,
abrasive and splashing objects, or exposed to harmful dusts, fumes, mists, vapors, or gases must
Hand Tools and Power Tools

39. be provided with the particular personal equipment necessary to protect them from the hazard.
Employees and employers have a responsibility to work together to establish safe working
procedures. If a hazardous situation is encountered, it should be brought to the attention of the
proper individual immediately.
Appropriate personal protective equipment should be worn due to hazards that may be
encountered while using portable power tools and hand tools.
Floors should be kept as clean and dry as possible to prevent accidental slips with or around
dangerous hand tools.
1.4 Identifytypesofhand tools,powertoolsandmaintenanceequipments.
General Hazards:
• The two most common hazards associated with the use of hand tools are misuse and improper
maintenance.
• Misuse occurs when a hand tool is used for something other than its intended purpose. (An
example would be using a screwdriver as a chisel. This may cause the tip to break and strike
someone).
• Improper maintenance allows hand tools to deteriorate into an unsafe condition.
(Examples would include cracked wooden handles that allow the tool head to fly off or
mushroomed heads that can shatter upon impact).
• Specially designed tools may be needed in hazardous environments. (Always use non-sparking
tools in the presence of flammable vapors or dusts. Insulated tools with appropriate ratings must
be used for electrical work).
Personal Protective Equipment:
• The type of personal protective equipment (PPE) needed when using hand tools depends on the
nature of the task. At a minimum, eye protection should always be worn.
• The use of hand protection may also be appropriate to provide protection against cuts, abrasion,
and repeated impact.
1.4.1 Listthe mostcommon typesofhand tool andpowertools.
Wrenches:
• Choose a wrench that properly fits the fastener that is to be turned. Using the correct size
reduces the chances of wrench slippage.
• Avoid using a length of pipe or other extension to improve the leverage of a wrench.
Manufacturers design wrenches so that the amount of leverage obtained with the handle is the
maximum safe application.
• Use socket wrenches for hard-to-reach areas.
• Always try to pull on a wrench (instead of pushing) in case the fastener suddenly loosens.
• Inspect wrenches periodically for damage such as cracking, severe wear, or distortion.

40. Pliers:
• Do not increase the handle length of pliers to gain more leverage. Use a larger pair of pliers or
bolt cutters.
• Do not substitute pliers for a wrench when turning nuts and bolts. Pliers cannot grip these items
properly and will slip.
• Never use pliers as a hammer or hammer on the handles. Such abuse is likely to result in cracks
or breaks.
• Cut hardened wire only with pliers designed for that purpose.
• Always cut at right angles. Never rock from side to side or bend the wire back and forth against
the cutting edges.
Hammers:
• Do not use a hammer if the handle is damaged or loose.
• Never weld, heat, or regrind a hammer head.
• Remove from service any hammer exhibiting signs of excessive wear such as cracks, chips, or
a mushroomed head.
• Match the proper type of hammer to the job it is designed to perform.
• Do not strike the surface at an angle. The hammer face should contact the striking surface
squarely. Glancing blows made with a hammer often lead to injury.
Screwdrivers:
• Never use a screwdriver as a pry bar, chisel, punch, stirrer, or scraper.
• Always use a screwdriver tip that properly fits the slot of the screw.
• Throw away screwdrivers with broken or worn handles.
• Use magnetic or screw-holding screwdrivers to start fasteners in tight areas.
• Never use pliers on a screwdriver for extra leverage. Only use a wrench on screw drivers
specifically designed to accept them.
Utility Knives/Blades:
• Always use a sharp blade. Dull blades require more force and thus are more likely to slip.
Replace the blade when it starts to ―tear‖ instead of cut.
• Never leave a knife unattended with the blade exposed. Consider using a selfretracting knife
with a spring-loaded blade. (The blade will retract when pressure on the knife is released).
• Keep your free hand away from the line of the cut.
• Don‘t bend or apply side loads to blades by using them to open cans or pry loose objects.
Blades are brittle and can snap easily.
1.4.2 Demonstratetheproperuseofvarious typesofhandtooland powertools.
1.4.3 Determine theimportanceofinspectingahand toolandpower
tools

41. Today’s Power Tools
Offer more power, adaptability and dependability than ever before.With enhanced tool
performance comes the responsibility to address power-tool safety issues. Maintenance
management professionals and technicians responsible for specifying and using power tools have
a responsibility to check out a tool's safety features, then ensure that manufacturer safety
precautions and common sense are followed at all times.
Hazards of Power Tools
All hazards involved in the use of power tools can be prevented by following five basic safety
rules:
i. Keep all tools in good condition with regular maintenance.
ii. Use the right tool for the job.
iii. Examine each tool for damage before use.
iv. Operate according to the manufacturer's instructions.
v. Provide and use the proper protective equipment.
vi. General Safety Guidelines for Power Tools
The following information offers general safety guidelines for power tools
Individual manufacturers' tool owner/operator manuals, shipped with tools and accessories, are
recommended as a final source for proper procedures for specific tool use.
General Safety Guidelines for Power Tools
i. Know the power tool.
ii. Operators must read and understand the owner's manual.
iii. Labels affixed or included in the shipping container must be read and understood.
iv. Ground all tools unless double insulated.
v. Avoid dangerous environments. Do not use power tools in a damp, wet and/or explosive
atmosphere -- fumes, dust or flammable materials.
General Safety Guidelines for Power Tools
i. Be aware of all power lines and electrical circuits, water pipes, and other mechanical
hazards in your work area, particularly those below the work surface, hidden from the
operator's view, that may be contacted.
ii. Wear proper apparel. Do not wear loose clothing, dangling objects or jewelry. Long hair
must be restrained. Gloves should not be worn when operating certain power tools.
Check appropriate tool manuals.
General Safety Guidelines for Power Tools
i. Power tools can be hazardous when improperly used.
ii. Employees should be trained in the use of all tools - not just power tools. They should
understand the potential hazards as well as the safety precautions to prevent those hazards
from occurring.
General Safety Guidelines for Power Tools

42. i. The following general precautions should be observed by power tool users:
ii. Never carry a tool by the cord or hose.
iii. Never yank the cord or the hose to disconnect it from the receptacle.
iv. Keep cords and hoses away from heat, oil, and sharp edges.
v. Disconnect tools when not in use, before servicing, and when changing accessories such
as blades, bits and cutters.
General Safety Guidelines for Power Tools
i. All observers should be kept at a safe distance away from the work area.
ii. Secure work with clamps or a vise, freeing both hands to operate the tool.
iii. Avoid accidental starting. Workers should not hold a finger on the switch button while
carrying a plugged-in tool.
General Safety Guidelines for Power Tools
i. Tools should be maintained with care. They should be kept sharp and clean for the best
performance. Follow instructions in the user's manual for lubricating and changing
accessories.
ii. Be sure to keep good footing and maintain good balance.
iii. The proper apparel should be worn. Loose clothing, ties, or jewelry can become caught in
moving parts.
iv. All portable electric tools that are damaged shall be removed from use and tagged "Do
Not Use."

43. 2IzharBin Ahmad (PTSB)
FadzliHaizamBin Hamzah (PSP)
1 Explain lubrication principle.
GENERAL
This section provides an overview of the fundamentals of lubrication. Included are
the basic properties and functions of a lubricant, and how a lubricant acts to reduce
friction and wear, dissipate heat, and prevent corrosion.
INTRODUCTION
The three major types of lubricants in use in industrial are LUBRICATING OILS,
GREASES, and SOLID LUBRICANTS. The selection of a lubricant type is
dependent on the type of machinery to be lubricated, the complexity of the
lubricating system allowed by machinery design, and the frequency of lubrication
required.
LUBRICATION
Learning Outcomes
Upon completion of this chapter, students should be able to:-
1. Understandlubrication principle.
2. Understandfluidmanagement.
3. Identifylubricatingdevicesandsystem.
4. Determinelubricatingprogram

44. LUBRICATING OILS
Lubricating oils are used for the majority of applications. They may be classified
according to their viscosities and any special properties imparted to them by
additives. Oils whose base stocks are derived primarily from crude oil refining are
called mineral or petroleum oils. Petroleum oils may be further classified as being
paraffinic or naphthenic based on the types of hydrocarbons comprising the base
stock. Oils that have been manufactured by chemical synthesis such as
polymerization are called synthetic oils. Additives may be blended into the base
stock to impart special properties to the finished product. A list of commonly used
lubricant additives is provided in Table 2.1
GREASES
Greases are typically used in situations where sufficient lube oil cannot be
effectively maintained on machinery surfaces, or when a simplistic lubricating
system is desired or required. Greases essentially consist of a semisolid mixture of
oil and thickening agent. The oil may be either petroleum or synthetic base.
Thickening agents are typically alkali soaps or clay (bentonite) materials. Critical
grease properties, such as hardness and water washout, are dependent on the
selection of base oil and thickening agent. For example, sodium-soap greases
exhibit poor water resistance; lithium-soap greases have good water resistance and
are excellent general purpose lubricants.
Table 2.1

45. Grease Application
Grease may be applied through grease cups or through hydraulic lubrication
fittings. Hydraulic lubrication fittings form a readily installed and convenient means
for lubricating numerous low-speeds, lightly loaded, or widely separated bearings.
These fittings are not acceptable for use on electric motors or generators because of
the danger of grease being forced out of the bearing and onto windings (refer to
NSTM Chapter 310, Electric Power Generators and Conversion Equipment,
for further discussion). A grease gun or other pressure device shall be used for
applying grease through hydraulic type fittings. When grease is applied through
hydraulic lubrication fittings, pressure should be applied until grease seeps out
around the edges of the bearings. In bearings fitted with felt or other seals, care
shall be exercised to avoid breaking the seals by the application of too much
pressure. If not, the bearing will fail due to a lack of lubrication. The type of fitting
should be identified and carbon steel fittings which are corroded should be replaced
with Corrosion Resistant Steel (CRES) or Monel fittings.
SOLID LUBRICANTS
Solid lubricants are typically used in situations where unusual temperature or
environmental conditions preclude the use of conventional fluid lubricants, or when
the application of a fluid lubricant is difficult. Solid lubricants form an essentially
dry lubricating film between adjacent surfaces. The lubricant may be applied
directly in powdered form, or as a colloidal suspension in a vehicle such as
isopropanol. Evaporation of the vehicle leaves a thin film of the lubricant on
machinery surfaces. The two most commonly used solid lubricants are powdered
graphite and molybdenum disulfide (MoS2). Other materials such as powdered zinc
dust and red lead suspended in petrolatum or mineral oil may also be used. Specific
solid lubricant applications are as follows:
Dry Graphite conforming to ss-G-659
May be used for the lubrication of such equipment as security locks. Powdered
molybdenum disulfide conforming to MIL-L-7866 is used primarily as a thread anti
seize compound. For the lubrication of threaded steel nuts and bolts, including
superheated steam components up to 565°C (1050°F), high temperature antiseize
compound conforming to MIL-A-907 is typically used. This lubricant consists of a
mixture of graphite and molybdenum disulfide suspended in mineral oil. For
threaded aluminum parts engaged with similar or dissimilar metals, zinc dust-
petrolatum anti seize compound MIL-T-22361 shall be used. Additional lubricants
for use on threaded fasteners include colloidal graphite in isopropanol (MIL-L-
24131) and molybdenum disulfide in isopropanol (MIL-L-24478).

46. FRICTION AND WEAR
The surfaces of machinery components appear well-finished to the naked eye.
When magnified, however, surface imperfections become readily apparent. These
microscopic hills and valleys are called asperities. When dry surfaces move relative
to one another, asperities may rub, lock together, and break apart. The resistance
generated when these adjacent surfaces come in contact is called friction. The
welding together and breaking apart of asperities is a form of adhesive wear.
Another form of wear may occur when a hard contaminant particle becomes
trapped between two opposing surfaces. When this occurs, the contaminant acts as a
miniature lathe, cutting into the softer machinery surface. This process is termed
abrasive wear. Another consequence of friction is that the energy created by
resistance is converted into heat. The primary functions of a lubricant, then, are the
formation of a protective film between adjacent surfaces to reduce wear, and the
dissipation of heat generated at these wear surfaces.
CORROSION PROTECTION
A second role provided by a lubricant is the prevention of system corrosion. In
environments where contamination of the system with water is likely, protection of
machinery components from corrosion is of the utmost importance. Salt water is
considerably more corrosive than fresh water. Water molecules may also diffuse
through the lubricant and enter surface micro cracks, causing hydrogen
embrittlement and subsequent surface failure. It is thus imperative that water
contamination of machinery systems be minimized. To achieve corrosion
protection, lubricants must form a protective barrier on machinery surfaces. Modern
day lubricants often contain corrosion inhibitors which chemically bond to the
metallic surfaces of equipment components. Corrosion inhibitors are an example of
a class of compounds called additives.
2.1.1 Describe lubrication system and benefit implement lubrication system.
An organized lubrication program should be an important component of
preventive maintenance. Machinery is costly, and newer models designed
for greater precision and faster production certainly require proper
lubrication. An organized lubrication program will reduce the possibility of
breakdowns and save on repairs, downtime, and lost production. Successful
lubrication programs involve both management and plant personnel.

47. 2.1.2 State several term and principle to understand and select proper lubrication.
There are ten (10) terms and principals as stated below:
a) Viscosity
b) Cloud point and pour point
c) Flash point and fire point
d) Neutralization number
e) Total base number
f) Water content
g) Demulsibility
h) Hardness
i) Water washout
j) Load carrying ability
a) Viscosity.
The most important physical property of a lubricant is its viscosity. Viscosity,
which may be defined as a fluid‘s resistance to flow, is the characteristic most
frequently stipulated by equipment manufacturers when making lubricant
recommendations. The selection of proper lubricant viscosity is often a compromise
between selecting one high enough to prevent metal to metal (wear) contact, and
one low enough to allow sufficient heat dissipation. In the past, viscosity was
measured in such units as Saybolt Universal Seconds (SUS),Redwood No. 1
Seconds, and Engler Degrees. The preferred unit of measurement for the U.S.
Navy is the centistokes (cSt). Kinematic viscosity in centistokes is obtained by
measuring the time required for a specified volume of fluid to flow through a
calibrated capillary tube at a specified temperature. Various industry standards exist
for the characterization of lubricant viscosity. The most familiar of these is the
Society of Automotive Engineers (S.A.E.) classification of automotive engine and
gear case oils. (Table 2.2) This system grades lubricants according to their viscosity
characteristics at either -18°C (0°F) or 100°C (212°F). Oils meeting low
temperature viscosity requirements are assigned a Wafter the grade number (for
example, SAE grade 10W). Oils meeting high temperature requirements are
assigned a grade number such as SAE grade 30. Multi grade oils may be formulated
to meet both low and high temperature requirements (for example, SAE grade
10W-30). However, these viscosity designations are applicable primarily for the
lubrication of internal combustion engines. By international agreement, all nations
now recognize a universally applicable system of viscosity classification termed the
International Standards Organization (ISO)/American Society of Testing and
Materials (ASTM) Viscosity System for Industrial Lubricants. This system assigns
viscosity grades from ISO VG2 through VG1500, where the number indicates the
midpoint viscosity in centistokes of the lubricant at 40°C (104°F).
Table 2.1

48. b
)
V
i
s
c
o
s
i
t
y
I
n
d
e
x
The effect of temperature on a lubricant‘s viscosity is a measurement of its
Viscosity Index (VI). When the VI scale was introduced in 1929, a reference
paraffinic base stock was assigned a VI of 100, and a naphthenic base stock
a VI of 0. Most naval oils of paraffinic base stock have VI‘s in the 95-100
range. Naval oils prepared from synthetic stock, and multi grade engine oils
typically have VI‘s in excess of 100. (Synthetic and paraffinic stocks are
discussed further in detail in paragraph (Table 2.3). The higher the VI, the
less a given lubricant‘s viscosity will change with a subsequent change in
temperature.
c) Cloud Point and Pour Point
Since petroleum stock consists of a mixture of molecular components,
lubricants do not exhibit sharp freezing points. Rather, as a lubricant is
cooled, certain components such as waxes will begin to precipitate out and
become evident in the liquid as a cloud. The temperature at which this
Table 2.3

49. occurs is called the cloud point of the lubricant. If the product is further
cooled, a point will be reached at which the lubricant will no longer flow or
be efficiently pumped. The temperature at which this occurs is termed the
pour point of the lubricant. Both properties are related to the wax content of
the base stock. The pour points of high-wax lubricants may be depressed by
the addition of pour point depressant additives. Pour point behavior
becomes important in applications such as refrigerant compressor
lubrication where the oil is subjected to low temperatures.
d) Flash Point and Fire Point
As a lubricant is heated, lighter components begin to vaporize.
The temperature at which sufficient vapor concentration exists above the
surface of the lubricant so that ignition with a test flame is possible is called
the flash point of the product. Flash point is useful for both product storage
requirements and for the detection of contamination of one product with
another. The fire point of a lubricant is that temperature at which sufficient
vapors are present above the surface of the lubricant to sustain combustion
upon ignition. This parameter is useful for storage and safety considerations.
e) Neutralization Number
As petroleum products are subjected to elevated temperatures, the process of
oxidation occurs. Oxidation leads to the formation of organic acids in the
lubricant. This increase in acidity reduces the water-separating ability of
certain oils, and may also prove corrosive to certain alloys. The
neutralization number measures the amount of acidity present in the
lubricant. It is quantitatively defined as the amount of potassium hydroxide
(KOH) required neutralizing the acid present in one gram of sample. This
quantity is also referred to as the Total Acid Number (TAN).
f) Total Base Number
Internal combustion engine oils are formulated with a highly alkaline (base)
additive package designed to neutralize the acidic byproducts of
combustion. The Total Base Number (TBN) is a measure of this additive
package, and it may be used as an indication of when diesel engine oil
should be changed.
g) Water Content
The most common contaminant in Naval lubricating systems is water.
Common sources of water include lube oil cooler leaks, condensation, steam
turbine gland seal leaks, and diesel engine piston blow-by and jacket water

50. leaks. The acceleration of system corrosion by water contamination cannot
be overemphasized. In addition, excessive water contamination increases the
viscosity and decreases the fluid film strength of oil. This may result in
accelerated wear due to rupture of the oil film and resultant surface to
surface contact. A qualitative assessment of the amount of water present in
some lubricants may be made by inspecting the oils‘ appearance. Another
method for determining water contamination levels is the Bottom Sediment
& Water (B.S.& W.) test.
h) Demulsibility
Demulsibility refers to a lubricant‘s ability to readily separate from water.
Oils used in force-feed lubrication systems should possess good water
reparability to prevent emulsification.
i) Hardness
Greases are classified according to a hardness scale developed by the
National Lubricating Grease Institute (NLGI). According to this system,
softer greases are assigned a low NLGI number, and stiffer greases a high
NLGI number (see Table 2.4). The penetration numbers refer to the depth,
in tenths of millimeters, that a weighted cone penetrates the grease. Most
Naval greases have NLGI numbers from 1 to 2, and are classified as
medium consistency greases.
j) Dropping Point
Greases exist in an essentially semi-solid form. The temperature at which
grease changes from a semi-solid to a liquid is termed its dropping point.
Dropping point provides some indication of the high temperature
characteristics of grease.
k) Water Washout
Greases subjected to splashing or impinging water must possess good water
washout resistance. Greases with good resistance will maintain an adequate
lubricating film under excessive water contamination conditions.
l) Load Carrying Ability
The ability of a lubricant to maintain an effective lubricating film under high
loads or pressures is a measure of its load carrying or extreme pressure (EP)

51. characteristics. The load carrying ability of a lubricant may be enhanced by
the addition of EP additives (see Table 2.1).
2.2 Distinguish fluid management.
2.2.1 Apply four essential components in a fluid management program.
In lubrication there five (5) essential components as stated below:
a) Selection and purchase of lubrication.
b) Lubrication monitoring during use.
c) Lubricant maintenance using processing.
d) Refortification techniques.
e) Disposal of the spent lubricant.
a) Selection and purchase of lubrication
Fluid management begins with purchasing the correct lubricant for the
application. For most equipment, premium long-lasting lubricants meeting
equipment manufacturers‘ recommendations and specifications should be
purchased. During the competitive bidding process, purchasing personnel
should carefully consider the supplier, products, and services. A supplier
should be chosen on the basis of the quality of lubricants and services
(engineering lubrication surveys, troubleshooting, used oil analyses, etc.)
offered rather than on price alone. The overall cost of lubrication compared
with the total cost of plant equipment is relatively insignificant. Purchase of
lubricants on the basis of price alone is not justified when considering the
cost of downtime for repair and lost productivity if attributed to the use of
an inferior lubricant. On the other hand, purchase of premium-grade
lubricants will not improve or correct lubrication problems if mechanical
Table 2.4

52. factors such as misalignment or severe environments (high levels of dirt and
water contaminants) are involved.
b) Lubrication monitoring during use
Monitoring programs may be used to determine the condition of the
lubricant and to detect early signs of equipment failure. Used oil analyses
also can be used to extend lubricant life and establish oil change out
intervals. The properties that should be monitored are dependent on the
application and environment. Table 1.2 lists the properties and condemning
limits for most large-volume applications of industrial lubricants, namely,
turbine/circulating, hydraulic, compressors, and gear oils. Other lubricant
applications, such as slide ways, rock drills, etc., which involve small
volumes and/or once through applications, need no monitoring. The results
of monitoring tests can be used in some cases to correct conditions that are
contributing to degradation of the lubricant. For example, if the lubricant in
a circulating system shows that water is present, it may be possible to locate
and eliminate the source of the water. If the viscosity is dropping, it may be
determined that incorrect oil is being used for makeup, or there may be
leakage of a different lubricant into the system. The condemning limits
shown in the table are intended to serve as general guidelines. The lubricant
supplier should provide actual limits for the products being used and
interpretation of used oil test results.
c) Lubricant maintenance using processing
Lubricant maintenance is closely associated with the monitoring program.
When used oil test results exceed the condemning limits, corrective action
needs to be taken. Such action could include filtration to remove particulate
matter and in some cases oxidation products and/or dehydration. This
processing can be done either on site or at a recycle station. Additive
replenishment for depleted inhibitors may be feasible for some products in
some applications. Since additive replenishment requires a considerable
amount of technical expertise, the lubricant supplier should be contacted to
provide information and service to reclaim and refortify used lubricants.
d) Refortification techniques
Lubricant maintenance is closely associated with the monitoring program.
When used oil test results exceed the condemning limits, corrective action
needs to be taken. Such action could include filtration to remove particulate
matter and in some cases oxidation products and/or dehydration. This
processing can be done either on site or at a recycle station. Additive
replenishment for depleted inhibitors may be feasible for some products in
some applications. Since additive replenishment requires a considerable
amount of technical expertise, the lubricant supplier should be contacted to
provide information and service to reclaim and refortify used lubricants.

53. e) Disposal of the spent lubricant.
Disposal is the last step that must be addressed in fluid management when
the monitoring results indicate that the oil is severely degraded and/or
depleted of additives that cannot be restored. Various options to consider
include recycling, burning, land-filling, and re-refining. The most
appropriate method of disposal will depend on local, state, and federal
regulations. These will clearly be affected by the location, which makes the
best method of disposal site-specific. Lubricant disposal needs to be
considered carefully on a case-by-case basis.
2.3 Understand lubrication protection.
Proper handling and storage of lubricants and greases are important to
ensure longevity and satisfactory performance. Premium-grade products
should be stored inside to prevent contamination with dirt and water and to
protect against temperature extremes. If drums are stored outside, they
should be stored on their sides, tilted, or upside down. Drums will expand
and contract as the temperature changes and any water on top of a drum may
be drawn through the bung as the drum expands and contracts. Ester- and
polyglycol-based lubricants need especially to be protected from
atmospheric humidity.

54. 2.3.1 Organize lubrication protection in term of:
a) Location and personal
b) Facilities for handling container
c) Lighting
d) Bulk storage
e) Fire protection
a) Location and Personnel
A clean, well-lighted room or building is advisable, with provisions for
heating in cold weather. It should be specifically kept for lubricant storage
and reserve lubricating equipment. In most plants, one or two individuals
are assigned the responsibility for inventory and dispensing of lubricants.
These individuals should be trained on the importance of protecting
lubricants from contamination and commingling with other lubricants.
Drums should be labeled clearly to ensure application/use of the correct
lubricant.
b) Facilities for Handling Containers
One-level handling is an important item wherever possible in planning for
lubricant storage. If practical, the floor level should be the same as the
delivery-truck floor. This facilitates rolling of drums into the storeroom,
where racks can be arranged along one or more walls so that oil drums can
be raised by a forklift truck and spotted in order to draw the contents off
with the least effort into distribution containers. Each drum should have its
own spigot to avoid commingling of products. Grease drums are normally
stored on end because the contents are removed by paddle, scoop, or
pressure pump, according to the consistency of the grease. Paddles, scoops,
and other devices must be kept clean to protect against abrasive particles
and dirt. In large plants, where a considerable volume of lubricants must be
stored, a set of parallel rails (see Fig. 2.1) is useful for handling full drums
to service racks as well as empties for return.

55. FIGURE 2.1
c) Lighting
This relates to good records. The lubrication and maintenance departments
can function most effectively when they have complete records as to
lubricant consumption per machine per area. This requires careful inventory
(monthly) and recording of amounts of oil and grease issued. Lighting plays
an important part. If the storeroom is painted gloss white, if light outlets are
well located to obviate glare, and if a comfortable record desk is installed,
personnel will keep more careful records.
d) Bulk Storage
Bulk storage can be an investment that provides benefits in improved
efficiency, reduced handling costs, reduced risk of contamination, and
simplified inventory. Each product requires its own dedicated bulk storage
system, including tank, pump, and receiving line. The tank should be
equipped with a water draw-off line, sampling line, and entry to permit
periodic tank cleaning. If tanks are equipped with electric heating coils or
steam lines, precautions must be taken to prevent overheating and thermal
degradation of the lubricant. Bulk shipments may be supplied in tank cars,
tank trucks, or tote bins. Upon arrival of bulk shipments, each product
should be inspected visually for clarity and cleanliness and checked for
viscosity with a handheld viscometer. Prior to unloading, each tank should
be gauged to ensure sufficient room. Tank lines and valves should be
checked to ensure that the product is being unloaded into the correct tank. If
dedicated lines and pumps are not being used, the system should be flushed

56. with one to three times the volume of the lines to prevent cross-
contamination of products. Samples should be obtained from the tank after
unloading and labeled with product name, date, invoice number, and batch
number. The samples should be stored for at least 6 months.
e) Fire Protection
The possibility of fire in a well-planned lubricant storage area is remote,
assuming that no-smoking rules are observed, that casual visits from other
plant personnel are prohibited, that oil drip is prevented or cleaned up
promptly, that waste or wiping rags are stored in metal containers and in
minimum quantity, and that sparking or arcing tools are used only under
conditions of good ventilation. Even so, insurance regulations will require
installation of suitable fire-extinguishing equipment and possibly a sprinkler
system. The accepted foam-type device for smothering is best. In a small
storeroom, one or two hand units may suffice. In a larger area, a multiple-
gallon foam cart with adequate hose may be required.
2.3 Identify lubricating devices and system.
LUBRICANT SELECTION
When choosing a lubricant for a particular piece of equipment, the equipment
manufacturer‘s operation and maintenance manual should be consulted. The
operation and maintenance manual will usually outline the required
characteristics of the lubricants as well as a recommended schedule for
replacement or filtering. If the maintenance manual is not available, or is vague
in its recommendations, lubricant manufacturers and distributors are other
sources of information. All the pertinent information on the equipment, such as
operating speed, frequency of operation, operating temperature, and any other
special or unusual conditions, should be provided to the lubricant manufacturer
or distributor so that a lubricant with the proper characteristics can be chosen.
Some discretion should be used when dealing with a lubricant salesperson to
prevent purchasing an expensive lubricant with capabilities in excess of what is
required.
Whenever possible, lubricants should be purchased that can be used in several
applications. By limiting the number of lubricants onsite, the chance of mixing
different lubricants or using the wrong lubricant is minimized.
LUBRICANT STANDARDS
There are a number of tests and standards that have been developed to define
and measure the properties of lubricants. Most of these tests have been
standardized by ASTM. The properties determined by these tests can be very

57. helpful in comparing relative performance of several lubricants, but it should be
noted that many of these tests have little correlation to actual service
conditions. When selecting a lubricant, the test procedures for the required
properties should be reviewed so that the relevance of the test is kept in
perspective.
2.3.2 Choose suitable lubricating devices system based on equipment or mechanical
components.
CHARACTERISTICS OF LUBRICATING METHODS
To evaluate a particular method for a specific application, certain characteristics should be
considered. Following evaluation criteria can serve as a checklist to aid in selection of
lubricating devices.
CATEGORIES OF LUBRICATION METHODS
The methods for lubricating machine elements can be divided into following
categories:
A. Manual Devices
B. Drop-feed Devices
C. Splash or bath lubrication
D. Ring, chain, collar oilers
E. Pad - and waste-type devices
F. Positive force feed lubricators
G. Air oil devices
H. Pressure circulating systems
I. Centralized lubricating systems
J. Built-in-lubrication
A. Manual Devices
Lubricating methods may require human action in one form or another. The
term manual lubrication applies to methods in which the operator is directly
responsible for quantity of lubricant and interval of lubrication. Although the
initial cost of manual lubrication is low, the maintenance costs can be high.
Reliability may be owing to considerable dependence on human action. The
lubricant is quite prone in contamination. Generally speaking, manual
lubrication is satisfactory only for lightly loaded or low speed bearings, typical
applications include open gears, chains, wire rope, etc.
B. Drop-feed Devices
Drop feed devices are gravity-flow lubricators. They are employed to deliver
lubricant drop-by-drop to individual bearings and other machine elements.
They give the best advantage when lubricant points are readily accessible. Their
cost is relatively low. Maintenance cost depends on type of service and location
depending on the lubricator, lubricant flow may or may not be stopped and
started automatically. Automatic operation increase reliability. Typical service

58. applications include journal and roller bearings, gears, chains, engine guides,
pumps and compressors.
C. Splash or Bath Lubrication
This type of lubrication is commonly used for machinery having high speed
moving parts. These dip into oil and splash it on to the bearings or other
machine elements. The splash system requires enclosing the mechanism to be
lubricated. Initial cost of splash system depends on the expense incurred in
enclosing the mechanism. Maintenance costs are low. A splash system is
reliable, prevents contamination. Typical applications include internal-
combustion engines, chain drives and enclosed gear sets.
D. Ring, Chain, Oilers
These lubricators are applicable to horizontal rotating shafts. The ring or chain
oiler encircles the shaft and turns freely on it. Each provides an automatic oiling
system by bringing oil to the bearing clearance from the oil reservoir. Initial
cost depends on housing for the bearing that must be built to contain these
lubricators. Maintenance cost is usually low. Typical applications include
electric motors, fans, blowers, compressors, and line shaft bearings.
E. Pad-and Waste-type Devices
These lubricators use the oil-retaining properties of felt pads and waste packing
to provide the lubricant to a bearing. Oil is lifted from the reservoir by capillary
action in the wicking material. This system requires an appropriate housing,
which accounts for a large initial cost. Maintenance cost generally depends on
the environment in which they are used. They are generally low. This is often
used for rail, road and traction motor bearings
F. Positive Force feed Lubricators
It consists of one or more plunger-type adjustable-stroke pumps mounted on a
common reservoir. The pumps are driven from a rotating shaft through a
mechanical linkage. It may have a separate drive motor. Initial cost is high, but
maintenance cost is low. The lubricant is free from contamination. Typical
applications include steam cylinders, bearings for diesel and gas engines.
G. Air-oil Devices
Air-oil devices operate by injecting or pumping oil drop-by-drop into an air
stream. The oil is drawn by the aspiratory action of compressed air passing
through an orifice or control valve. The initial-cost is very high. However,
maintenance costs are low and efficiency of the devices is high. These are well
suited for high speed bearings, enclosed gears, slides and table ways.
H. Pressure Circulating Systems:
Pressure circulating systems employ either gravity or pumps to develop the
operating pressures necessary. Generally these are designed to lubricate a
number of parts on the machine. Since oil is recirculated maximum economy is
possible. Pressure circulating systems are built into the machine. Therefore
initial cost is high. Maintenance costs are very low. Typical applications

59. include steam-turbine bearings, reduction gears, steel-mill gear drives, mill
bearings, paper-machine bearings and gears and internal-combustion engines.
I. Centralized Lubrication Systems
Centralized Systems can be designed for oil or grease. A typical centralized
system requires centrally located reservoir and pump, and permanently installed
piping and distribution valves. These deliver measures quantities of lubricant at
desired points. It can be either operated manually or automatically. The piping
and intricate dispensing valves make initial cost very high, but maintenance
costs are very low. Initial cost is offset by dependability, durability, safety and
resistance of system to contamination.
Centralized Systems are ideally suited for steel and paper mills, machine tools
etc.
J. Built-in-Lubrication
Built-in lubrication refers to materials or components that do not require any
external lubricating device. Materials such as oil saturated porous metals,
graphite materials, PTFE, nylon can rub together without a lubricant. These
materials may be used for sleeve bearings, gears etc. components have built-
in lubrication are well suited for use in inaccessible locations. They can
reduce maintenance costs, but should not be used indiscriminately. The
various categories of lubrication systems have been very briefly discussed in
the above paragraphs. There are, however, very many varieties in each
finding specific applications. Depending upon the severity of the working
situation of machine elements the most suitable means from cost,
maintenance and efficiency point of view should be selected.
2.4 Determine lubricating program.
a. The plant lubrication survey.
b. Establishment of lubrication schedules and improvements in
selection and application of lubrication.
c. Lubrication analysis
2.4 Determine lubricating program.
a. The plant lubrication survey.
A workable lubrication schedule should be developed, after the job of a
lubricant is defined. How much, where and when? Time and effort is required
to adequately cover all areas of the equipment to determine lubrication needs.
A physical survey is the only way to establish a complete schedule for an
lubrication points on each machine. Check the OEM (Original Equipment
Manufacturer) manual for lubrication requirements such as type and
frequency of service, number of lubrication points and recommended

60. lubricant.
b. Lubrication schedules establishment and improvements in selection and application
of lubrication.
The activities to achieve and carry out an effective lubrication program are outlined
in this segment and they consist of:
1. The plant lubrication survey
2. Establishment of lubrication schedules
3. Improvement in the selection
4. Applications of lubricants
5. Lubricant analysis
6. Fluids management
7. Quality assurance,
All above activities required to implement the programs, and factors to consider if a
single supplier source is desired for all plant lubricants.The program implement or
should work closely with plant personnel to determine information now available
and programs and procedures presently being used.
The Plant Lubrication Survey
1. Identify equipment and component parts requiring lubrication, the specific
location of each machine, and the model, serial number, function, manufacturer,
operating instructions, and limitations.
2. Obtain similar information for each subcomponent of the machine, such as drive
motors, gears, couplings, and bearings.
3. Examine the lubricant recommendations made by the machine or parts
manufacturer and supporting documentation for these selections.
4. Determine the lubricants currently used, including quantity, cost, and supply
source.
5. List the schedules in effect for each lubrication point, including frequency,
quantity applied, and sampling schedules. Provide similar information for all
machine components.
6. Identify the nature of each lubrication point and whether circulating systems are
fed from central storage tanks, individual machine sumps, or grease fittings and
whether manual, semiautomatic, or automatic equipment is now being used.
Operating characteristics, condition, and effectiveness of the lubrication systems
encountered should be determined.
7. Make a detailed visual inspection of each machine and its components for
indications of problems, such as leakage; excessive noise; high temperature;
vibration; and loose, damaged, or missing parts.
8. Record information relating to the adequacy of the machine to perform its
intended functions.
Note: An effective approach for conducting the initial lubrication survey is to start
with the units of equipment that are critical to maintaining continuous production
and work toward the less critical units. This approach will achieve the greatest
results in the shortest time period. When surveying an individual machine, start at

61. the power source and follow through each power train, identifying couplings,
reducers, bearings, and wear surfaces.
Establishment of Lubrication Schedules and Improvements in Selection and
Application of Lubricants
1. Review current lubrication schedules, including type and amount of lubricant
used and frequency of application.
2. Determine if it is the best lubricant for the specific application commensurate with
the proposed lubricant product reduction program and improved performance
requirements.
3. Analyze each piece of equipment to determine if the present lubrication system is
adequate and if the lubrication points or central reservoirs are readily accessible.
4. Investigate opportunities to replace inadequate systems, manual systems, and
malfunctioning automatic systems with state-of-the-art automatic systems that can
be justified through reduced labor, increased equipment reliability, and/or reduced
energy costs.
5. Analyze operating records such as frequency of scheduled and unscheduled
downtime and reason for each shutdown when preparing the new lubrication
schedule.
6. Establish lubrication schedules and routings to minimize travel time and
interference with production operations. Determine time required to perform
specific lubrication functions and number of workers required to perform the job.
7. Establish a check-off or feedback procedure to indicate that the scheduled
lubrication was accomplished with the proper lubricant.
8. Record and report the amount and type of lubricant consumed in each area and on
major pieces of equipment.
9. New equipment lubrication specifications are to be determined prior to
installation of the equipment.
10. Place tags at each fill point that calls out lubricant to be used, amount of lubricant,
and lubrication schedule.
Lubricant Analysis
1. Establish the objectives of the analysis program, that is, monitor and track wear
and lubricant quality to detect problems caused by adhesion, friction, and
corrosion before there is major component damage and to determine when
lubricant should be filtered, replaced, and/or fortified with additives.
2. Select the plant equipment to be included in the analysis program. Equipment
selection is usually based on the importance of the equipment to continuity of
plant operations.
3. Determine the sampling frequencies for each component.
4. Design the testing packages to meet the selected objectives. Typical tests for gear
reducer lubricants include :

62. Wear particle analysis—wear metals, contaminate metals, and
additive metals
Total solids percentage volume—contamination leaks or
environmental conditions
Viscosity—fluidity of the lubricant
Infrared analysis—oxidation/nitration (general lube degradation)
Neutralization number—reserve alkalinity (Total base number
[TBN])or total acidity (Total acid number [TAN])
5. Select a lubricant testing laboratory that can accurately test the parameters chosen
and report the results in a comprehensive manner on a timely basis.
6. Determine the cost of the analysis program.
7. Develop the sampling procedures and modify equipment as necessary to extract
representative samples while the equipment is in operation.
8. Establish sampling, testing, and reporting schedules.
9. Develop procedures and lines of communication to report results and to initiate
actions dictated by the test results.
10. Establish a program review schedule.
Note: A close liaison should be maintained between the lubricant analysis program and other
predictive maintenance activities.
b. Lubrication Analysis
1. Establish the objectives of the analysis program, that is, monitor and track wear
and lubricant quality to detect problems caused by adhesion, friction, and
corrosion before there is major component damage and to determine when
lubricant should be filtered, replaced, and/or fortified with additives.
2. Select the plant equipment to be included in the analysis program. Equipment
selection is usually based on the importance of the equipment to continuity of
plant operations.
3. Determine the sampling frequencies for each component.
4. Design the testing packages to meet the selected objectives. Typical tests for gear
reducer lubricants Include Wear particle analysis—wear metals; contaminate
metals, and additive metals
Total solids percentage volume—contamination leaks or environmental
conditions Viscosity—fluidity of the lubricant
Infrared analysis—oxidation/nitration (general lube degradation)
Neutralization number—reserve alkalinity (Total base number [TBN]) or total
acidity (Total acid number [TAN])
5. Select a lubricant testing laboratory that can accurately test the parameters chosen
and report the results in a comprehensive manner on a timely basis.
6. Determine the cost of the analysis program.

63. 3
7. Develop the sampling procedures and modify equipment as necessary to extract
representative samples while the equipment is in operation.
8. Establish sampling, testing, and reporting schedules.
9. Develop procedures and lines of communication to report results and to initiate
actions dictated by the test results.
10. Establish a program review schedule.
Note: A close liaison should be maintained between the lubricant analysis program and
other predictive maintenance activities.
References
Asseff, P.A., Lubrication Theory and Practice, The Lubrizol Corporation.
Bloch, H.P., Practical Lubrication for Industrial Facilities, Fairmont Press, 2000
Conoco Inc., Lubrication Manual, 1981.
Ehrlich, M. (Ed), Lubricating Grease Guide, National Lubricating Grease Institute, 1st Edition,
Kansas City, Missouri, 1984.
Exxon Corporation, Proving Ground, 1988.
Fein, R.S., and F.J. Villforth, Lubrication Fundamentals, LUBRICATION, vol. 59, October-
December 1973.
Pirro, D.M., A.A. Wessol, Lubricant Fundamentals, 2nd Edition, Marcel Dekker, Inc., 2001.
Rein, S.W., Viscosity-I, LUBRICATION, vol. 64, No. 1, 1978.
Standard Guide for Cleaning, Flushing, and Purification of Steam, Gas and Hydroelectric Turbine
Lubrication Systems, ASTM Standard No.D6439-99.
Troyer, D., and J. Fitch, Oil Analysis Basics, Noria Corporation, 2001.
U.S. Army Corps of Engineers, Lubricants and Hydraulic Fluids, Engineering Manual 1110-2-
1424, 1999.
POWERTRANSMISSIO

64. Nor HishamBin Suhadi (PIS)
Abdul Rashid Bin Talib (PMK)
Arman Bin Md. Said (PMM)
POWERTRANSMISSION
INTRODUCTION
Power transmission is the movement of energy from its place of generation to a location where
it is applied to performing useful work.Power is defined formally as units of energy per
unit time.
3.1 Describethedrivemechanismintheprocessoftransformingpower from one pointtotheother.
Mechanical power may be transmitted directly using a component such
as driveshaft,transmission gears, belt drives, chain drives and arm connectors.
3.1.1 Classifytypesof drivemechanismsbeltdrive, chaindrive and gear drive
i. Belt Drive
A belt is a loop of flexible material used to link two or more rotating shafts mechanically.
Learning Outcomes
Upon completion of this chapter, students should be able to:-
1. Describethedrivemechanismintheprocessoftransformingpower fromone
pointtotheother.
2. Describegear in powertransmissionsystem.
3. Definebeltdrives inpower transmissionsystem
4. Understandchain drive.
5. Implementcoupledshaftalignment orvariable-speed drives

65. ii. Chain Drive
Chain passing over a pair of sprocket, with the teeth of the sprocket meshing with the holes in
the links of the chain.Drive chains are most often made of metalwell-made chains may prove
stronger than belts.
iii. Gear Drive
A gear is a rotatingmachine part having cut teeth, or cogs, which mesh with another toothed part
in order to transmit torque. The most common situation gears are meshing each other. However a
gear can also mesh a non-rotating toothed parts. The gears in a transmission are analogous to the
wheels in a pulley. An advantage of gears is that the teeth of a gear prevent slipping. When two

66. gears of unequal number of teeth are combined a mechanical advantage is produced, with both
the rotational speeds and the torques of the two gears differing in a simple relationship.
3.2 Describegear in powertransmissionsystem.
3.2.1 Listapplicationofgear.
i. Transmission
Two or more gears working in tandem are called atransmission and produce a mechanical
advantagethrough a gear ratio and thus may be considered a simple machine. In transmissions
which offer multiple gear ratios, such as bicycles and cars, the term gear, as in first gear, refers
to a gear ratio rather than an actual physical gear. The term is used to describe similar devices
even when gear ratio is continuous rather than discrete, or when the device does not actually
contain any gears, as in a continuously variable transmission.
ii. Direction
Geared devices can change the speed, magnitude, and direction of a power source.
A system called a rack and pinion, when circular motion is changed into linear motion. If the
pinion rotates in a fixed position and non-rotating toothed part the rack moves in a linear motion,
therebyproducing translation. Adjacent gears on a gear train rotate in opposite directions. Notice
that if the driver rotates clockwise then the follower rotates anticlockwise.
iii. Couplings
A coupling is a device used to connect two shafts together at their ends for the purpose of
transmitting power. Couplings do not normally allow disconnection of shafts during operation,
however there are torque limiting couplings which can slip or disconnect when some torque limit
is exceeded.
The primary purpose of couplings is to join two pieces of rotating equipment while permitting
some degree of misalignment or end movement or both. By careful selection, installation and
maintenance of couplings, substantial savings can be made in reduced maintenance costs and
downtime.
3.2.2 Classifytypes ofgearsandtheir characteristics basedonit‘sfunction.

67. i. External vs internal gears
Internal gear
An external gear is one with the teeth formed on the outer surface of a cylinder or cone.
Conversely, an internal gear is one with the teeth formed on the inner surface of a cylinder or
cone. For bevel gears, an internal gear is one with the pitch angle exceeding 90 degrees. Internal
gears do not cause output shaft direction reversal.
ii. Spur
Spur gear
Spur gears or straight-cut gears are the simplest type of gear. They consist of a cylinder or disk
with the teeth projecting radially, and although they are not straight-sided in form, the edge of
each tooth is straight and aligned parallel to the axis of rotation. These gears can be meshed
together correctly only if they are fitted to parallel shafts.
iii. Helical

68. Helical gears
Helical or "dry fixed" gears offer a refinement over spur gears. The leading edges of the teeth are
not parallel to the axis of rotation, but are set at an angle. Since the gear is curved, this angling
causes the tooth shape to be a segment of a helix. Helical gears can be meshed in parallel or
crossed orientations. The former refers to when the shafts are parallel to each other; this is the
most common orientation. In the latter, the shafts are non-parallel, and in this configuration the
gears are sometimes known as "skew gears".
The angled teeth engage more gradually than do spur gear teeth, causing them to run more
smoothly and quietly. With parallel helical gears, each pair of teeth first make contact at a single
point at one side of the gear wheel; a moving curve of contact then grows gradually across the
tooth face to a maximum then recedes until the teeth break contact at a single point on the
opposite side. In spur gears, teeth suddenly meet at a line contact across their entire width
causing stress and noise. Spur gears make a characteristic whine at high speeds. Whereas spur
gears are used for low speed applications and those situations where noise control is not a
problem, the use of helical gears is indicated when the application involves high speeds, large
power transmission, or where noise abatement is important. The speed is considered to be high
when the pitch line velocity exceeds 25 m/s.
A disadvantage of helical gears is a resultant thrust along the axis of the gear, which needs to be
accommodated by appropriate thrust bearings, and a greater degree of sliding friction between
the meshing teeth, often addressed with additives in the lubricant.
iv. Skew gears
For a 'crossed' or 'skew' configuration, the gears must have the same pressure angle and normal
pitch; however, the helix angle and handedness can be different. The relationship between the
two shafts is actually defined by the helix angle(s) of the two shafts and the handedness.
The crossed configuration is less mechanically sound because there is only a point contact
between the gears, whereas in the parallel configuration there is a line contact.
Quite commonly, helical gears are used with the helix angle of one having the negative of the
helix angle of the other; such a pair might also be referred to as having a right-handed helix and a

69. left-handed helix of equal angles. The two equal but opposite angles add to zero: the angle
between shafts is zero – that is, the shafts are parallel. Where the sum or the difference (as
described in the equations above) is not zero the shafts are crossed. For shafts crossed at right
angles, the helix angles are of the same hand because they must add to 90 degrees.
v. Double helical
Double helical gears
Double helical gears, or herringbone gears, overcome the problem of axial thrust presented by
"single" helical gears, by having two sets of teeth that are set in a V shape. A double helical gear
can be thought of as two mirrored helical gears joined together. This arrangement cancels out the
net axial thrust, since each half of the gear thrusts in the opposite direction resulting in a net axial
force of zero. This arrangement can remove the need for thrust bearings. However, double
helical gears are more difficult to manufacture due to their more complicated shape.
For both possible rotational directions, there exist two possible arrangements for the oppositely-
oriented helical gears or gear faces. One arrangement is stable, and the other is unstable. In a
stable orientation, the helical gear faces are oriented so that each axial force is directed toward
the center of the gear. In an unstable orientation, both axial forces are directed away from the
center of the gear. In both arrangements, the total (or net) axial force on each gear is zero when
the gears are aligned correctly. If the gears become misaligned in the axial direction, the unstable
arrangement will generate a net force that may lead to disassembly of the gear train, while the
stable arrangement generates a net corrective force. If the direction of rotation is reversed, the
direction of the axial thrusts is also reversed, so a stable configuration becomes unstable, and
vice versa.
Stable double helical gears can be directly interchanged with spur gears without any need for
different bearings.

70. vi. Bevel
Bevel Gear
A bevel gear is shaped like a right circular cone with most of its tip cut off. When two bevel
gears mesh, their imaginary vertices must occupy the same point. Their shaft axes also intersect
at this point, forming an arbitrary non-straight angle between the shafts. The angle between the
shafts can be anything except zero or 180 degrees. Bevel gears with equal numbers of teeth and
shaft axes at 90 degrees are called miter gears.
vii. Spiral bevels
Spiral bevel gears
The teeth of a bevel gear may be straight-cut as with spur gears, or they may be cut in a variety
of other shapes. Spiral bevel gear teeth are curved along the tooth's length and set at an angle,
analogously to the way helical gear teeth are set at an angle compared to spur gear teeth. Zerol
bevel gears have teeth which are curved along their length, but not angled. Spiral bevel gears
have the same advantages and disadvantages relative to their straight-cut cousins as helical gears
do to spur gears. Straight bevel gears are generally used only at speeds below 5 m/s (1000
ft/min), or, for small gears, 1000 r.p.m.

71. viii. Hypoid
Hypoid gear
Hypoid gears resemble spiral bevel gears except the shaft axes do not intersect. The pitch
surfaces appear conical but, to compensate for the offset shaft, are in fact hyperboloids of
revolution. Hypoid gears are almost always designed to operate with shafts at 90 degrees.
Depending on which side the shaft is offset to, relative to the angling of the teeth, contact
between hypoid gear teeth may be even smoother and more gradual than with spiral bevel gear
teeth. Also, the pinion can be designed with fewer teeth than a spiral bevel pinion, with the result
that gear ratios of 60:1 and higher are feasible using a single set of hypoid gears. This style of
gear is most commonly found driving mechanical differentials; which are normally straight cut
bevel gears; in motor vehicle axles.
ix. Crown
Crown gear
Crown gears or contrate gears are a particular form of bevel gear whose teeth project at right
angles to the plane of the wheel; in their orientation the teeth resemble the points on a crown. A
crown gear can only mesh accurately with another bevel gear, although crown gears are
sometimes seen meshing with spur gears. A crown gear is also sometimes meshed with an
escapement such as found in mechanical clocks.

72. x. Worm
Worm gear
4-start worm and wheel
Worm gears resemble screws. A worm gear is usually meshed with a spur gear or a helical gear,
which is called the gear, wheel, or worm wheel.
Worm-and-gear sets are a simple and compact way to achieve a high torque, low speed gear
ratio. For example, helical gears are normally limited to gear ratios of less than 10:1 while worm-
and-gear sets vary from 10:1 to 500:1. A disadvantage is the potential for considerable sliding
action, leading to low efficiency.
Worm gears can be considered a species of helical gear, but its helix angle is usually somewhat
large (close to 90 degrees) and its body is usually fairly long in the axial direction; and it is these
attributes which give it screw like qualities. The distinction between a worm and a helical gear is
made when at least one tooth persists for a full rotation around the helix. If this occurs, it is a
'worm'; if not, it is a 'helical gear'. A worm may have as few as one tooth. If that tooth persists for
several turns around the helix, the worm will appear, superficially, to have more than one tooth,
but what one in fact sees is the same tooth reappearing at intervals along the length of the worm.
The usual screw nomenclature applies: a one-toothed worm is called single thread or single start;
a worm with more than one tooth is called multiple thread or multiple start. The helix angle of a
worm is not usually specified. Instead, the lead angle, which is equal to 90 degrees minus the
helix angle, is given.

73. In a worm-and-gear set, the worm can always drive the gear. However, if the gear attempts to
drive the worm, it may or may not succeed. Particularly if the lead angle is small, the gear's teeth
may simply lock against the worm's teeth, because the force component circumferential to the
worm is not sufficient to overcome friction. Worm-and-gear sets that do lock are called self
locking, which can be used to advantage, as for instance when it is desired to set the position of a
mechanism by turning the worm and then have the mechanism hold that position. An example is
the machine head found on some types of stringed instruments.
If the gear in a worm-and-gear set is an ordinary helical gear only a single point of contact will
be achieved. If medium to high power transmission is desired, the tooth shape of the gear is
modified to achieve more intimate contact by making both gears partially envelop each other.
This is done by making both concave and joining them at a saddle point; this is called a cone-
drive or "Double enveloping"
Worm gears can be right or left-handed, following the long-established practice for screw threads
xi. Non-circular
Non-circular gears
Non-circular gears are designed for special purposes. While a regular gear is optimized to
transmit torque to another engaged member with minimum noise and wear and maximum
efficiency, a non-circular gear's main objective might be ratio variations, axle displacement
oscillations and more. Common applications include textile machines, potentiometers and
continuously variable transmissions.
xii. Rack and pinion

74. Rack and pinion gearing
A rack is a toothed bar or rod that can be thought of as a sector gear with an infinitely large
radius of curvature. Torque can be converted to linear force by meshing a rack with a pinion: the
pinion turns; the rack moves in a straight line. Such a mechanism is used in automobiles to
convert the rotation of the steering wheel into the left-to-right motion of the tie rod(s). Racks also
feature in the theory of gear geometry, where, for instance, the tooth shape of an interchangeable
set of gears may be specified for the rack (infinite radius), and the tooth shapes for gears of
particular actual radii are then derived from that. The rack and pinion gear type is employed in a
rack railway.
xiii. Epicyclic
Epicyclic gearing
In epicyclic gearing one or more of the gear axes moves. Examples are sun and planet gearing
(see below) and mechanical differentials.
xiv. Sun and planet

75. Sun and planet gearing was a method of converting reciprocating motion into rotary motion in
steam engines. It was famously used by James Watt on his early steam engines in order to get
around the patent on the crank.
In the illustration, the sun is yellow, the planet red, the reciprocating arm is blue, the flywheel is
green and the driveshaft is grey.
xv. Harmonic drive
Harmonic drive gearing
A harmonic drive is a specialized gearing mechanism often used in industrial motion control,
robotics and aerospace for its advantages over traditional gearing systems, including lack of
backlash, compactness and high gear ratios.
xvi. Cage gear

76. Cage gear in Pantigo Windmill, Long Island
A cage gear, also called a lantern gear or lantern pinion has cylindrical rods for teeth, parallel to
the axle and arranged in a circle around it, much as the bars on a round bird cage or lantern. The
assembly is held together by disks at either end into which the tooth rods and axle are set.
Lantern gears are more efficient than solid pinions, and dirt can fall through the rods rather than
becoming trapped and increasing wear.
Sometimes used in clocks, the lantern pinion should always be driven by a gearwheel, not used
as the driver. The lantern pinion was not initially favoured by conservative clock makers. It
became popular in turret clocks where dirty working conditions were most commonplace.
Domestic American clock movements often used them.
xvii. Magnetic gear
All cogs of each gear component of magnetic gears act as a constant magnet with periodic
alternation of opposite magnetic poles on mating surfaces. Gear components are mounted with a
backlash capability similar to other mechanical gearings. At low load, such gears work without
touching, giving increased reliability without noise.
3.2.3Identify gearmeshingandbacklash.
In a pair of gears backlash is the amount of clearance between the meshing tooth. Backlash
unavoidable for nearly all reversing mechanical components that are coupled but could be
minimized.

77. 3.2.4 Explain coupling concept into gear system.
When power transmission occurs between two or more pairs of gears drive and driven, gear pairs
serves as a coupling.
Gears As A Coupling;
• Gears are also used to connect two nominally coaxial shafts.
• This joint allows for minor misalignments such as installation errors and changes in
shaft alignment due to operating conditions.
• Each joint consists of a 1:1 gear ratio internal/external gear pair.
• The tooth flanks and outer diameter of the external gear are crowned to allow for
angular displacement between the two gears.
• Purpose of couplings is to join two pieces of rotating equipment while.
3.2.5Identifygearmaintenancepracticesuchasdailyroutine inspection.
The routine inspection includes of;
a. LUBRICATION
In order for a gear drive to operate at all time, it must be supply with an adequate lubricant.
Check the oil level or grease and change if necessary.
b. VIBRATIONS
In order for a gear drive to operate satisfactory, it must run within safe vibration limits. If the
vibration parameters (amplitude, velocity or acceleration) change with time above a given limit,
it could also means something is wrong.
c. ALIGNMENT
If the alignment of a gear drives to the connected load is not made carefully the coupling may
fail. The coupling can then transmits bending moments back into gear drives.
d. BACKLASH
Check the backlash of a gear drives using filler gauge, dial test indicator or sheet materials.
e. GEAR TOOTH WEAR
Check for tooth surface deterioration and tooth breakage by visual inspection.
f. TOOTH CONTACT
The most satisfactory way of checking tooth contact is to apply a very thin coating of engineers
marking blue or other marking medium. The tooth contact will indicate the proper gears mesh of
a gear drives to rotate smoothly.
3.2.6 Assembleanddisassembleafewtypesofgearsa practical.As an examples
componentscanbeuseisassemblyspurgearexercise or assemblyspur wheel /wormgear

78. station.
ATTACHMENT
1. LAB SHEET FOR STUDENT:
POLITEKNIK
IBRAHIMSULTANFACULTYOFMECHANICALENGINEE
RING
DIPLOMA INMECHANICALENGINEERING
REPORT
JJ615 MECHANICALCOMPONENTS & MAINTENANCE (GEAR
DRIVES)
CLO:
1. Assemble correctly mechanical component base on service manual
maintenancebygroup.(P5)
2. Organize properly maintenance procedure base on standard operation
procedure.(A4)
1.
NAME:
REGISTERATIONNO: SESSION:
PROGRAMME

79. PRACTICAL DATE SUBMITTED DATE
LECTURER
PREPAREDBY:
NOR HISHAM BIN SUHADI
CHECKEDBY:
(HEADOFDEPARTMENT/HEADOFPROGRAM
ME)
RUBRICS
LearningDomain (LD1)Knowledge
Tools 5@3@1/5 (x4)
Procedure/Sketches 5@3@1/5 (x5)
Maintenance Procedure 5@3@1/ 5(x5)
Discussion/Conclusion 5@3@1/ 5(x3)
Neatness/Teamwork/cooperation 5@3@1/ 5(x3)
TOTALMARKS /100 x 30% =
TITLE : ASSEMBLE AND DISASEMBLE OF GEAR DRIVE SYSTEM
1.0 COURSE LEARNING OUTCOMES
Upon completion of this workshop, students should be able to :
1.1 Assemblecorrectlymechanicalcomponent base onservicemanualmaintenance by group. (P4)
1.2 Organizeproperlymaintenanceprocedurebaseonstandardoperation procedure.
(A4)
1.3 Practice safety procedures correctly in the working workshop according to the workshop
safety regulation to create a secure practical team work (A3).
2.0 OBJECTIVES
2.1 Producemaintenanceprocedure for a gear drives drives.
2.2 Assembleanddisassembleagear drives system as a practical.As an
examplescomponentcanbe
use is gear station unit.
3.0 APPARATUS/EQUIPMENT
3.1 Gear Station
3.2 Hand Tools
3.3 Power Tools
3.4 Lubricant
3.4 Solvent
3.5 Air Compressor
4.0 SAFETY AND HEALTH

80. It is the individual’s responsibility to practice the following general safety guidelines at all times
and keep your workspace reasonably tidy.
4.1 Always know the hazards associated with the equipment/materials that are being utilized in
the workshop.
4.2 Always wear appropriate protective clothing and equipment.
4.3 Confine long hair and loose clothing. Do not wear high-heeled shoes, open-toed shoes,
sandals
or shoes made of woven material.
4.4 Be familiar with the location of emergency equipment such as fire alarm and fire
extinguisher.
Know the appropriate emergency response procedures.
5.0 INTRODUCTION
A gear is a rotatingmachine part having cut teeth, or cogs, which mesh with another
toothed part in order to transmit torque. Two or more gears working in tandem are
called a transmission and can produce a mechanical advantage through a gear ratio
and thus may be considered a simple machine. Geared devices can change the speed,
magnitude, and direction of a power source. The most common situation is for a gear to
mesh with another gear, however a gear can also mesh a non-rotating toothed part,
called a rack, thereby producing translation instead of rotation.
The gears in a transmission are analogous to the wheels in a pulley. An advantage of
gears is that the teeth of a gear prevent slipping.
When two gears of unequal number of teeth are combined a mechanical advantage is
produced, with both the rotational speeds and the torques of the two gears differing in a
simple relationship.
In transmissions which offer multiple gear ratios, such as bicycles and cars, the term
gear, as in first gear, refers to a gear ratio rather than an actual physical gear. The term
is used to describe similar devices even when gear ratio is continuous rather than
discrete.
6.0 TOOLS:
NO TOOLS DESCRIPTION TOOLS USAGE
7.0 DIASSEMBLE AND ASSEMBLE PROCEDURES:

81. NO EXPLANATION FIGURES/SKETCHES
1
2
3
4
.
ETC
8.0 COMPLETE MAINTENANCE PROCEDURE FOR A GEAR DRIVES
9.0 DISCUSION / CONCLUSION
1. PRACTICLE RUBRIC
RUBRIC FOR COMBINE GEAR DRIVE SYSTEM PRACTICLE
Generic
Student
Attributes
(GSA) /
Learning
Domain
(LD)
Skills /
Aspects
Excellent
Very
Good
Good Fair Unsatisfactory
5 4 3 2 1

82. LD 2 /
Practical
Skills Gear
Drives
A)
Demonstrate
the proper
use of various
types of hand
tool and
power tools.
Able to select/choose
various types of hand
tools and power
tools. Able to use
various types of hand
tools and power
tools with the proper
function of the tools.
Able to use
various types
of hand tools
and power
tools with the
proper
function of
the tools.
Unable to use
various types of
hand tools and
power tools with
the proper
function of the
tools.
B) Assemble
and
disassemble
of gear drive
system
Able to select /
choose various types
of hand tool and
power tools to
assemble and
disassemble belt
drive system. Able to
use various types of
hand tools and
power tools with the
proper function of
the tools to assemble
and disassemble belt
drive system.
Able to use
various types
of hand tools
and power
tools with the
proper
function of
the tools to
assemble and
disassemble
belt drive
system.
Unable to use
various types of
hand tools and
power tools with
the proper
function of the
tools to assemble
and disassemble
of belt drive
system.
c) Alignment
of gear drive.
Able to select /
choose the tool for
shafts and gears
alignment. Able to
use tools for shafts
and gears alignment.
Able to use
tools for
shafts and
gears
alignment.
Unable to use
tools for shafts
and gears
alignment.
3.2.7Developmaintenanceprocedure for a gear drive system.

83. Belt Drives in Power Transmission
 A belt is a looped strip of flexible material, used to mechanically link two or more
rotating shafts.
 They may be used as a source of motion, to efficiently transmit power, or to track
relative movement. Belts are looped over pulleys.
 In a two pulley system, the belt can either drive the pulleys in the same direction, or
the belt may be crossed, so that the direction of the shafts is opposite.
Figure 3.1: Belt Drive
3.3.1 List of Belt Drives Applications
 Transmit Power
A combination of mechanical components to change the speed or torque of
mechanical energy. Transmit power is achieved by specially designed belts and
pulleys. One or both of the pulleys are powered to moving the belt. The powered
pulley is called the drive pulley while the unpowered pulley is called the idler.

84. Figure 3.2: Power transmission using belt drive
 Conveyor.
A conveyor system is mechanical handling equipment that moves materials from
one location to another. Conveyors are especially useful in applications involving
the transportation of heavy or bulky materials
Figure 3.3: Conveyor
Industries using these applications are:
• Automotive
• Blenders
• Converting
• Conveyors
• Farming
• Feeder Drives
• Food Processing
• Electrical generators
• Robotics
• Medical
• Mixers
• Movie Animation
• Office Machines
• Packaging
• Electrical generators
• Power Transmission
Distributors
• Material Handling
3.3.2 5 Types Of Belt Drives

85. Table 3.1: Types of Belt Drives
1. Flat belts - used to transfer power from the engine's
flywheel. It can deliver high power at high speeds
(500 hp at 10,000 ft/min), in cases of wide belts and
large pulleys. It can deliver high power at high speeds
(500 hp at 10,000 ft/min), in cases of wide belts and
large pulleys. Flat belts were traditionally made of
leather or fabric. Today some are made of rubber or
polymers.
2. Round belts - Round belts are a circular cross section
belt designed to run in a pulley with a 60 degree V-
groove. Round grooves are only suitable for idler
pulleys that guide the belt, or when (soft) O-ring type
belts are used. The V-groove transmits torque through
a wedging action, thus increasing friction.
Nevertheless, round belts are for use in relatively low
torque situations only and may be purchased in
various lengths or cut to length and joined, either by a
staple, a metallic connector (in the case of hollow
plastic), gluing or welding (in the case of
polyurethane). Early sewing machines utilized a
leather belt, joined either by a metal staple or glued,
to great effect.
3. Vee belts - (also known as V-belt or wedge rope)
solved the slippage and alignment problem. It is now
the basic belt for power transmission. They provide
the best combination of traction, speed of movement,
load of the bearings, and long service life. They are
generally endless, and their general cross-section
shape is trapezoidal (hence the name "V"). The "V"
shape of the belt tracks in a mating groove in the
pulley (or sheave), with the result that the belt cannot
slip off. Optimal speed range is 1000–7000 ft/min.
4. Multi-groove belts or polygroove belt - is made up of
usually 5 or 6 "V" shapes alongside each other. This
gives a thinner belt for the same drive surface, thus it
is more flexible, although often wider. The added
flexibility offers an improved efficiency, as less
energy is wasted in the internal friction of continually

86. bending the belt. In practice this gain of efficiency
causes a reduced heating effect on the belt and a
cooler-running belt lasts longer in service. They can
run over pulleys on the ungrooved back of the belt.
5. Ribbed belt - is a power transmission belt featuring
lengthwise grooves. It operates from contact between
the ribs of the belt and the grooves in the pulley. Its
single-piece structure is reported to offer an even
distribution of tension across the width of the pulley
where the belt is in contact, a power range up to
600 kW, a high speed ratio, serpentine drives
(possibility to drive off the back of the belt), long life,
stability and homogeneity of the drive tension, and
reduced vibration. The ribbed belt may be fitted on
various applications: compressors, fitness bikes,
agricultural machinery, food mixers, washing
machines, lawn mowers, etc.
6. Film belts - though often grouped with flat belts, they
are actually a different kind. They consist of a very
thin belt (0.5-15 millimetres or 100-4000
micrometres) strip of plastic and occasionally rubber.
They are generally intended for low-power (10 hp or
7 kW), high-speed uses, allowing high efficiency (up
to 98%) and long life. These are seen in business
machines, printers, tape recorders, and other light-
duty operations.
7. Toothed belts (also known as timing, notch, cog, or
synchronous belts) - are positive transfer belts and can
track relative movement. These belts have teeth that
fit into a matching toothed pulley. When correctly
tensioned, they have no slippage, run at constant
speed, and are often used to transfer direct motion for
indexing or timing purposes. They can bear up to
200 hp (150 kW) at speeds of 16,000 ft/min.
* choose 5 types only
3.3.3 Belt tension and misalignment of belt drives

87. Belt tension
• The ideal belt is that of the lowest tension which does not slip in high loads.
• Belt tensions should also be adjusted to belt type, size, speed, and pulley
diameters.
• Belt tension is determined by measuring the force to deflect the belt a given
distance per inch of pulley.
• Timing belts need only adequate tension to keep the belt in contact with the
pulley.
Figure: 3.4: belt tensioner
Misalignment
 Belt drive misalignment exists when the driver and driven sheaves are not
properly aligned.
 Misalignment can take either the form of angular or parallel (offset)
misalignment, or a combination of both.
 Angular misalignment occurs when the faces of the sheaves do not form a straight
line.
 With parallel misalignment, the sheaves may be in angular alignment, but their
position on the shaft creates a parallel offset.
Angular misalignment. Parallel misalignment.
Figure 3.5: misalignment
3.3.4 Check list drive belt maintenance
There are several things need to be addressed before performing maintenance is charged
which is:

88.  Always shut off power, lock and tag control box.
 Place all machine components in safe position.
 Remove guard, inspect and clean.
 Inspect belt for wear, damage. Replace as needed.
 Inspect sheaves or sprockets for wear, alignment. Replace if worn.
 Inspect other drive components such as bearings, shafts, motor mounts and take
up rails.
 Inspect static conductive grounding system (if used) and replace components as
needed.
 Check belt tension and adjust as needed.
 Recheck pulley alignment.
 Reinstall belt guard.
 Restart drive. Look and listen for anything unusual.
Table 3.2: Table of symptoms, probable cause and solution
PREMATURE BELT FAILURE
SYMPTOMS PROBABLE CAUSE SOLUTION
Broken belt
1.Under-designed drive 1. Redesign using Drive
Design Manual.
2.Belt rolled or prised onto
pulley
2. Use drive take up when
installing.
3.object falling into drive
3. Provide adequate guard or
drive protection.
4.Severe shock load
4. Redesign to accommodate
shock load.
Belt fail to carry load
(slip);no visible reason
1.Under-designed drive
1. Redesign using Drive
Design Manual
2.Damaged tensile member
2. Follow correct installation
procedure.
3.Worn pulley grooves
3. Check for groove wear.
Replace as needed.
4.Contre distance movement
4. Check drive for centre
distance movement during
operation.
Edge cord failure
1.Pulley misalignment
1. Check and correct
alignment.
2.Damaged tensile member
2. Follow installation
procedure.
Belt delamination or under
cord separation
1.Pulleys too small
1. Check and design, replace
with larger pulleys.
2.Back idler too small
2. lncrease back idler to
acceptable diameter.

89. Wear on belt top surface
1.Rubbing against guard 1. Replace or repair guard.
2.ldler malfunction 2. Replace idler.
Wear on belt top corner
1.Belt-to-pulley fit incorrect
(belt too small for groove)
1. Use correct belt-to-pulley
combination.
Wear on belt bottom corners
1.Belt slip
1.Retension until slipping
stops
2.Misalignment 2. Realign pulleys.
3.Worn pulleys 3. Replace pulleys.
4.lncorrect belt
4. Replace with correct belt
size.
SEVERE OR ABNORMAL BELT WEAR
SYMPTOMS PROBABLE CAUSE SOLUTION
Wear on belt bottom corners
1.Belt-to-pulley fit incorrect
1. Use correct belt-to-pulley
combination.
2.Worm pulleys 2. Replace pulleys.
Wear on belt bottom corners
1.Belt bottoming on pulley
groove
1. Use correct belt/pulley
match.
2.Worn pulleys 2. Replace pulleys.
3.Deberis in pulleys 3. Clean pulleys.
Under cord cracking
1.Pulley diameter too small
1. Use larger diameter
pulleys.
2.Belt slip 2. Retension.
3.Back idler too small 3. Use larger diameter back
idler.
4.lmproper storage
4. Do not coil belt too tightly,
kink or bend. Avoid heat and
direct sunlight.
Burn or hardening on bottom
or sidewall
1.Belt slip
1. Retension until slipping
stops.
2. Worn pulleys 2. Replace pulleys.
3. Under-designed drive
3. Redesign using drive
Design Manual
4. Shaft movement
4. Check for centre distance
changes
Extensive hardening of belt
exterior
1.Hot drive environment 1.Improve ventilation to drive
Belt surface flaking, sticky
or swollen
1.Oil or chemical
contamination
1. Do not use belt dressing.
Eliminate sources of oil,
grease or chemical
contamination.
BANDED (JOINED)BELT PROBLEMS

90. SYMPTOMS PROBABLE CAUSE SOLUTION
Tie-band separation
1.Worn pulleys 1. Replace pulleys.
2. improper groove spacing
2. Use standard groove
pulleys
Top of tie-band frayed, worn
or damaged
1. Interference with guard 1. Check guard.
2. Back idler malfunction or
damaged
2. Repair' or replace back
idler.
comes off drive 1.Debris in pulleys
1. Clean grooves. Use single
belts to prevent debris from
being trapped in grooves.
One or more ribs run outside
of pulley
1.Misalignment 1. Realign drive.
2. Under tensioned 2. Retension.
BELT NOISE AND UNUSUAL VIBRATITION
SYMPTOMS
PROBABLE CAUSE SOLUTION
Squeal or "chirp"
1.Belt slip 1. Retension.
2. Contamination 2.Clean belts and pulleys
Slapping noise
1.Loose belts 1. Retension.
2. Mismatched set 2. Install matched belt set.
3. Misalignment
3. Realign pulleys so all belts
share load equally
Rubbing sound Guard interference
1. Repair, replace or redesign
guard.
Grinding sound Damaged bearings Replace, align and lubricate
Unusually loud drive
1.Incorrect belt
1. Unusually loud drive23Use
correct belt size. Use correct
belt tooth profile for
sprockets on synchronous
drive.
2.Worn pulleys 2. Replace pulleys.
3. Debris in pulleys
3. Clean pulleys, improve
shielding, and remove rust,
paint or dirt from grooves.
Excessive vibration in drive
system
1.Incorrect belt
1. Use correct belt cross-
section in pulley.
2. Poor machine or
equipment design
2. Check structure and
brackets for adequate
strength.
3. Pulley out of round 3. Replace pulley.
4. Loose drive components 4. Check machine

91. components and guards,
motor mounts, motor pads,
bushings, brackets and
framework for stability,
adequate design strength,
proper maintenance and
proper installation.
WIBELT STRETCHESBEYOND
PROBLEM WITH SHEAVES, BELT STRETCHES BEYOND TAKE UP
SYMPTOMS PROBABLE CAUSE SOLUTION
Multiple belts stretch
unequally
1.Misaligned drive 1. Realign and retension
drive.
2. Debris in pulleys 2. Clean pulleys.
3. Broken tensile member or
cord damaged
3. Replace all belts, install
properly.
4. Mismatched belt set 4. Install matched belt set
Single belt, or where all belts
stretch evenly
1.Insufficient takeup
allowance
1. Check takeup. Use
allowance specified in Drive
Design Manual.
2. Grossly overloaded or
under-designed drive
2. Redesign drive.
3. Broken tensile members
3.Replace belt, install
properly
V-BELT TURN OVER OR JUMP OFF SHEAVE
SYMPTOMS PROBABLE CAUSE SOLUTION
lnvolves single or multiple
belts
1.Shock loading or vibration 1. Check drive design.
2. Foreign material in
grooves
2. Shield grooves and drive.
3. Misaligned pulleys Worn
pulley grooves
3. Realign pulleys.
4. Worn pulley grooves 4. Replace pulleys.
5. Damaged tensile member
5. Use correct installation and
belt storage procedure.
6. Incorrectly placed flat
idler pulley
6. Carefully place flat idler on
slack side of drive as close as
possible to driver pulleys.
7. Mismatched belt set
7. Replace with new set of
matched belts. Do not mix old
and new belts

92. 8. Poor drive design
8. Check for centre distance
stability and vibration
dampening.
3.4 Chain Drive in Power Transmission
3.4.1 General
A chain drive uses a sprocket and chain to drive machinery much like the belt drive. However,
since the belt drive uses friction to drive machinery, slippage can occur. The chain drive is a
positive or direct drive and does not allow slippage. A simple example of a chain drive is the
sprocket and chain on a bicycle or motorcycle.
The three basic applications of chain drive are:
1.Transmitting Power, chains and sprockets are used as flexible gearing to transmit torque from
one rotating shaft to another.
2.Converting Motion, chains are used to convey materials by sliding, pushing, pulling or
carrying.
3. Timing or Synchronizing, chains are used as devices to synchronizing movements such as
valve timing in automobiles or raising loads on an overhead chain hoist
3.4.2 TYPES OF CHAIN DRIVE
1. Roller chains are used in low- to mid-speed drives at around 600 to 800 feet per minute
2. A bicycle chain is a form of roller chain. Bicycle chains may have a master link, or may
require a chain tool for removal and installation. A similar but larger and thus stronger chain is
used on most motorcycles
3. In automobile engines, roller chains would drive the camshaft(s) off the crankshaft,
generating less noise than a gear drive as used in very high performance engines, and more
durable than timing belts.
4. Chains are also used in forklifts using hydraulic rams as a pulley to raise and lower the
carriage; however, these chains are not considered roller chains, but are classified as lift or leaf
chains.
5. Chainsawcutting chains superficially resemble roller chains but are more closely related
to leaf chains. They are driven by projecting drive links which also serve to locate the chain onto
the bar.

93. 6. Silent Chains are used for the camshaft drive of the mid- to large-size engines. Transfer-case
drive in four-wheel-drive vehicle.The primary drive between the engine and transmission, as
well as in other high-speed applications.
Sprockets
Sprockets types.
The three bacis sprockets types are identified by their hub arrangement.
Type A sprockets sometimes called plate sprockets, have no hubs and are used for mounting on
flanges, hubs or other devices . They are made from bar stock or hot-rolled plate in either solid or
split construction with plain, countersunk, or tapped holes. Holes sizes and bolt circle for which
jigs are available are indicated in the thye D sprocket .
Type B sprockets have a hub on one side only. Small and medium size sprockets are usually
furnised in type B and are turned from bar stock or forgings, or are made by welding a bar stock
hub to a hot-rolled plate sprocket. If required, large diameter type B sprockets can be furnished.
They can be welded hub construction or machined from gray iron castings.

94. Type C sprockets have hubs on both sides. Large diameter sprockets are furnised in type C, with
hub projections equidistant from the centerline of the sprockets. With this hub arrangement the
line of action due to chain pull reacts through the center of the hub, proving stability and assuring
an even distribution of stress on shafts and key. Offset hubs can be furnished.Type C sprockets
are normally machined from gray iron castings, but can be cast steel or welded hub construction.
Multiple width sprockets have a row of theeth to engage each strand of chain. They are made in
the same types as single width sprockets. That is smaller diameter sprockets are reguarly
furnished as type B and the larger sizes as type C.Mandrel bore sprockets are made in broad
range of sizesfor single and multiple strand chain.They are stocked
with mandrel bores for remaining to suit specification.
Finished bore sprockets are available for most widely used single strand chain. These ready to
use sprockets are made in type B only and are stocked in a range of popular bores , complete
with keyseats and set screw.

95. Taper lock sprockets are ideal where a positive, full compression grip on the shaft is desired.
They are available in a wide range of sizes for single and double strand chains. Bushing are
stocked in with bore increment, complete with key seat.
Special purpose sprockets. Type C split sprockets are used to facillate the installation or
replacement of sprockets locate where accessibility is difficuilt. They have a special split hub
and rim construction design for bolting the sprocket halves securely together.
Type D double duty sprockets offer convenience and economy when occasional drive ratio
change are necessary. They consists of a Type A plate sprocket bolted to a gray iron hub .

96. Shear pin sprockets are used to protect chain Drives and machinery from damage overloads.
They consists of a modified Type sprocket mounted on a gray iron hub and connected by a
shear pin. Many stock sizes are available.
Double pitch sprockets
Standard rollers.
Series C-2000 chains have rollers of the same diameters and widths as American
Standard Roller chains of one half the conveyor chain pitch. Engaged by every other tooth,
double duty sprockets have two teeth per chain pitch. During each revolution only half the teeth
function effectively. Sprockets with odd numbers of teeth will allow any given tooth to engage
only on every other revolution, automatically increasing sprocket life. Double duty sprockets
with even number of teeth may be manually advance one tooth periodically to increase sprocket
life. Martin stock C-2000 series sprockets are furnished double duty only.
Carrier rollers

97. Sprockets for the C-2000 series chain can roller are cut with space cutters or standard halve for
the American Standard Roller chain of the same diameter. Each sprocket tooth meshes with these
chains. Double sprockets cannot made for double pitch chain with Carrier Rollers. For drives of
31 teeth or more we recommend using Standard sprockets with series C2000 series chain. All
altered double pitch sprockets requiring all way will be furnished with key way on center of
tooth unless otherwise specified.
3.4.3 Installation.
To obtain maximum chain and sprocket life accurate alignment, proper chain tension , and good
lubrication are required. A drive is easy to install provided that precautions common to sound
judgement and good workmanship are followed. Poor installation eventually becomes evident in
the resulting reduction of chain life- more so on a high speed drive than on a low speed drive.
Simple precautions are sometimes forgotten, but they are essential-
All parts of the drive must be rigidly and securely mounted so that vibration cannot work them
loose.
1.The chain must be clean and free from grit and dirt before it is installed. Korosene is highly
effective cleaning agent.
2.The chain should articute freely. Make sure that parts are not damaged or bent and that
sprockets and shafts operate freely.
3.The drive must have adequate clearance . If chain case lubrication is used the drive must be
positioned correctly for chain clearance and the oil spray pipe adjusted properly.
During the start – up of the drive , make certain that all parts work smoothly and lubrication is
being properly applied to the chain.

98. Shaft and sprocket Alignment.
Mount the sprockets on their respectively shaft and align shafts horizontally with a machine‘s
level. Parallel alignment of the shaft should be made with a vernier caliper, or a feeler bar and
the distance between shafts on both sides of the sprocket should be equal. Sprocket tooth
engagement:- a straight edge or a taut wire may be applied to the machined surface of the
sprocket to assist in this alignment . Set screw must be tightened securely in the sprocket hub to
hold key in position and to guard against any lateral movement in the sprocket motors,
bearingetc, should then be bolted securely in place so that full alignment can be maintained
during the operation of the drive.
To Install.
1. Select the sprocket and bushing required and slide the bushing into the sprocket.
Be sure that all holes match up.
2. Place screws in threaded engagement with sprocket and free in bushing holes.
Slip assembled sprocket and bushing on shaft.

99. 3. Tighten screws to force tapered bushing into the taper-bored hub . This wedges
the bushing between the shaft and sprocket assuring the fit that is as tight as a
shrunk fit.
To removed
1. Removed the screws completely . Using one of them as a jackscrew, insert in hole threaded
on bushing so that it engages the bushing and is free of the hub. Tighten the jackscrew.

100. 2. As the jackscrew is tightened , the sprocket will become disengaged from the bushing
and the complete assembly may be easily slipped of the shaft.
Checking sprockets for wear.
To check for sprocket wear is easier, most can be seen by eye, but to be sure the wisest way is to
try a new chain in the teeth and see how much wear has taken place by the clearance that is
found between the teeth and the rollers or in between the side plates and the side of the sprocket
wall. Scored teeth or teeth with their tips worn off are also signs of wear, the charts in this
booklet will explain what corrections must take place to prevent the trouble from happening
again.
The examples of teeth damage can be easily by making sure that the chain is in good condition
and by ensuring that the sprockets are in line as well as being made of hardened steel. Normal
wear may also cause some tooth damage but it is usually all over type of wear and not limited to
just one side or one edge of the sprocket tooth.

101. 3.4.4 CHAIN DRIVE MAINTENANCE

102. 1.Check lubrication -
On slow speed drives, where manual lubrication is used, be sure the lubrication schedule is
being followed. If the chain is covered with dirt and debris, clean the chain with kerosene and
relubricate it.
WARNING! NEVER USE GASOLINE OR OTHER FLAMMABLE SOLVENTS TO CLEAN
A CHAIN. A FIRE MAY RESULT.
If drip lubrication is used, check for adequate oil flow and proper application to the chain. With
bath or pump lubrication, check oil level and add oil if needed. Check oil for contamination and
change oil if needed. Change oil after the first 100 hours of operation and each 500 hours
thereafter. If pump lubrication is used, check each orifice to be sure it is clear and is directing
oil onto the chain properly.
2. Check Chain Tension -
Check chain tension and adjust as needed to maintain the proper sag in the slack span. If
elongation exceeds the available adjustment, remove two pitches and reconnect the chain.
3. Check Chain Wear -
Measure the chain wear elongation and if elongation exceeds functional limits or is greater than
3% (.36 inches in one foot) replace the entire chain. Do not connect a new section of chain to a
worn chain because it may run rough and damage the drive. Do not continue to run a chain
worn beyond 3% elongation because the chain will not engage the sprockets properly and it
may damage the sprockets.
4. Check Sprocket Tooth Wear -
Check for roughness or binding when the chain engages or disengages from the sprocket.
Inspect the sprocket teeth for reduced tooth section and hooked tooth tips.
If these conditions are present, the sprocket teeth are excessively worn and the sprocket should
be replaced. Do not run new chain on worn sprockets as it will cause the new chain
to wear rapidly. Conversely, do not run a worn chain on new sprockets as it will cause the new
sprockets to wear rapidly.
5. Check Sprocket Alignment -
If there is noticeable wear on the inside surface of the chain roller link plates, the sprockets may
be misaligned. Realign the sprockets as outlined in the installation instructions to prevent further
abnormal chain and sprocket wear.
6. Check for Drive Interference -
Check for interference between the drive and other parts of the equipment. If there is any, correct
it immediately. Interference can cause abnormal and potentially destructive wear on the chain or
the interfering part. If the edges of the chain link plates impact against a rigid part, link plate
fatigue and chain failure can result.
Check for and eliminate any buildup of debris or foreign material between the chain and
sprockets.

103. A RELATIVELY SMALL AMOUNT OF DEBRIS IN THE SPROCKET ROLL SEAT CAN
CAUSE TENSILE LOADS GREAT ENOUGH TO BREAK THE CHAIN IF FORCED
THROUGH THE DRIVE.
7. Check for Failure -
Inspect the chain for cracked, broken or deformed parts. If any of these conditions are found,
REPLACE THE ENTIRE CHAIN, even though portions of the chain appear to be in good
condition. In all likelihood, the entire chain has been damaged.
3.5 COUPLED SHAFT ALIGNMENT
3.5.1 Fundamentals of shaft alignment
• A shaft is a rotating member, usually of circular cross section used to transmit torque and
rotation, to connect other components
• Types Of Misalignment
• Parallel / Off-Set Misalignment
• Angular Misalignment
• Combination Misalignment
Tools to measure shaft axis alignment condition
• it is possible to measure the alignment with dial gauges or feeler gages using various
mechanical setups.
• it is recommended to take care of bracket sag, parallax error while reading the values.
• it is very convenient to use laser shaft alignment technique to perform the alignment task
within highest accuracy.
• it is required to align the machine better, the laser shaft alignment tool can help to show
the required moves at the feet positions.
Requirements of good shaft alignment
• it should be easy to connect or disconnect attached components.
• it should transmit the full power from one shaft to other without losses.
• it does allow some misalignment between the two adjacent shaft rotation axis.
• it is the goal to minimize the remaining misalignment in running operation to maximize
power transmission and to maximize machine runtime (coupling and bearing and sealing
lifetime).
• it should have no projecting parts.
• it is recommended to use manufacturer's alignment target values to set up the machine
train to a defined non-zero alignment, due to the fact that later when the machine is at
operation temperature the alignment condition is perfect
VARIABLE SPEED DRIVES
CONTINUOS VARIABLE TRANSMISSION
• A transmission that can change steplessly through an infinite number of effective gear

104. ratios between maximum and minimum values.
• The flexibility of a CVT allows the input shaft to maintain a constant angular
velocity over a range of output velocities.
Types Of CVT
• Variable-diameter pulley (VDP) or Reeves drive
• Toroidal or roller-based CVT (Extroid CVT )
• Magnetic CVT or mCVT
• Infinitely Variable Transmission (IVT)
• Ratcheting CVT
• Hydrostatic CVTs
• Cone CVTs
• Radial roller CVT
• Planetary CVT
LAB SHEET
REPORT
JJ615 MECHANICALCOMPONENTS &
MAINTENANCE
CLO:
1. Assemble correctly mechanical component base on service manual
maintenancebygroup.(P5)
2. Organize properly maintenance procedure base on standard operation
procedure.(A4)
2.
NAME:
REGISTERATIONNO: SESSION:
PROGRAMME
PRACTICAL DATE SUBMITTED DATE
LECTURER
PREPAREDBY:
RUBRICS
LearningDomain (LD1)Knowledge

105. NOR HISHAM BIN SUHADI
CHECKEDBY:
(HEADOFDEPARTMENT/HEADOFPR
OGRAMME)
Introduction 5@3@1/5 (x4)
Procedure/Tools 5@3@1/5 (x5)
Maintenance Procedure 5@3@1/ 5(x5)
Discussion/Conclusion 5@3@1/ 5(x3)
Neatness/Teamwork 5@3@1/ 5(x3)
TOTALMARKS /100 x 30% =
TITLE : CHAIN DRIVES
5.0 COURSE LEARNING OUTCOMES
Upon completion of this workshop, students should be able to :
1.1 Assemblecorrectlymechanicalcomponent base onservicemanualmaintenance by group. (P4)
1.2 Organizeproperlymaintenanceprocedurebaseonstandardoperation procedure.(A4)
1.3 Practice safety procedures correctly in the working workshop according to the workshop
safety
regulation to create a secure practical team work (A3).
6.0 OBJECTIVES
2.1 Demonstratetheuseof thereversedialindicatormethodsto correct shaft misalignment.
2.2 Assembleanddisassembleofmechanicaldrivesystemasa practical.Asanexamples
apparatuscanbeusearegear assemblyforcombined drivesandalignment of drives, chain
drives and belt drives.
7.0 APPARATUS/EQUIPMENT
3.1 Chain Drive system
3.2 Hand Tools
3.3 Power Tools
3.4 Lubricant
3.4 Solvent
3.6 Air Compressor
4.0 SAFETY AND HEALTH
It is the individual’s responsibility to practice the following general safety guidelines at all times
and keep your workspace reasonably tidy.
4.1 Always know the hazards associated with the equipment/materials that are being utilized in
the workshop.
4.3 Always wear appropriate protective clothing and equipment.
4.3 Confine long hair and loose clothing. Do not wear high-heeled shoes, open-toed shoes,
sandals

106. or shoes made of woven material.
4.4 Be familiar with the location of emergency equipment such as fire alarm and fire
extinguisher.
Know the appropriate emergency response procedures.
10.0 INTRODUCTION
A shaft is a rotating member, usually of circular cross section used to transmit torque
and rotation, to connect other components of a drive train that cannot be connected
directly because of distance or the need to allow for relative movement between them.
It provides the axis of rotation, or oscillation of elements such as gears, pulleys,
sprockets, flywheels and the like and controls the geometry of their motion.
Shafts are carriers of torque: they are subject to torsion and shear stress, equivalent to
the difference between the input torque and the load. They must therefore be strong
enough to bear the stress, whilst avoiding too much additional weight as that would in
turn increase their inertia.
The designing of shaft must be studied from the following point of view:
1- Deflection and rigidity
a. Torsional deflection
b. Slope at bearings and shaft supported elements
c. Shear deflection due to transverse loading of short shafts
2- Stress and strength
a. Static strength
b. fatigue strength
c. Reliability
Chain drive is a way of transmitting mechanical power from one place to another. It is
often used to convey power to the wheels of a vehicle, particularly bicycles and
motorcycles. It is also used in a wide variety of machines besides vehicles.
Most often, the power is conveyed by a roller chain, known as the drive chain or
transmission chain, passing over a sprocket gear, with the teeth of the gear meshing
with the holes in the links of the chain. The gear is turned, and this pulls the chain
putting mechanical force into the system.
Sometimes the power is output by simply rotating the chain, which can be used to lift or
drag objects. In other situations, a second gear is placed and the power is recovered by
attaching shafts or hubs to this gear. Though drive chains are often simple oval loops,

107. they can also go around corners by placing more than two gears along the chain; gears
that do not put power into the system or transmit it out are generally known as idler-
wheels. By varying the diameter of the input and output gears with respect to each
other, the gear ratio can be altered.
11.0 ASSEMBLE AND DISASSEMBLE PROCEDURES
NO EXPLANATION FIGURES/SKETCHES TOOLS
1
2
3
ETC
7.0 MAINTENANCE PROCEDURE FOR CHAIN DRIVE :
8.0 DISCUSION / CONCLUSION

108. 4
KamalBin Haron (PSA)
Zulkhairi BinKhairudin(PSA)
4.0 BEARING
4.1 Bearing Concepts
4.1.1 Application of bearings
• A bearing is a machine element that constrains relative motion between moving parts to
only the desired motion.
• The design of the bearing may provide for free linear movement of the moving part or for
free rotation around a fixed axis or, it may prevent a motion by controlling the vectors of
normal forces that bear on the moving parts.
• Bearings are classified broadly according to the type of operation, the motions allowed,
or to the directions of the loads (forces) applied to the parts.
• Bearing are used to support rotating shaft and are classified according to the direction of
the main load. (see figure 4.1.1)
 axial bearing are design to withstand axial thrust
 Radial bearings are designed to withstand radial load
 Combination of both
BEARING
Learning Outcomes
Upon completion of this chapter, students should be able to:-
1. Understandbearingconcepts.
2. Understandfriction, temperature andlubrication.
3. Describe mountinganddismountingofbearing.
4. Understandbearingdamage.

109. Figure 4.1.1
• A bearing is constituted by an inner and an outer ring. Between them a series of rolling
element is found
• Something a fourth element (cage) is present to keep the rolling elements in their
position.
• Rolling elements can be spheres (ball bearing) or cylinders (cylinder roller bearings).
4.1.2 Types of bearing and characteristic of bearings
The bearings are classified broadly into two (2) categories based on the type of contact
they have between the rotating and the stationary member
a. Rolling Element Bearings
Rolling element bearing also called an antifriction bearing because the created by
this bearing is rolling friction rather than sliding friction creared by the plain
bearings.The rolling element bearing is a cylinder containing a moving inner ring of
stell balls or rollers.
Rolling element bearings have balls or roller for increase efficiency. Rolling friction
is always less than sliding friction.The following are the three basic types of rolling
element bearings.
i. Ball bearings
ii. Roller bearings.
iii. Needle Bearings.
Different designs of ball and roller bearings can handle radial, axial and combination
loads. Needle bearings are used only for radial or axial loads.

110. Figure 4.1.2 Needle bearing
b. Sliding / Journal / Plain Bearings
A plain bearing is any bearing using a sliding action rather than a rolling action. It
may or may not be lubricated. Plain bearings are sometimes referred to as journal or
sleeve bearings. Plain bearings are typically cylindrical shape bearings designed to
carry radial loads.The terms journal and sleeve are often used interchangeably :sleeve
refers to the general configuration, and journal refer to the part of the shaft in contact
with the bearings.Plain bearing may also be thrust bearings or thrust washers.
Plain bearing can categorized into three classes :
i. Class I
Bearing systems are lubricated from an outside sources
ii. Class II
Bearing systems have internal lubrication .
iii. Class III
Bearing systems have graphite , PTFE ( Teflon) or plastic bearings that
require no lubricant
Figure 4.1.21 Journal Bearing

112. Table 4.1.22 : Two main categories based on the type of contact
Type Description Friction Stiffness Speed Life Notes
Plain/journal/sliding bearing
Cylindrical sleeve that
support a rotating or sliding
shaft .The inner lining, called
the
bushing, is usually made of a
metal softer then
that‘s of the shaft so that any
wear occurs in the replaceable
bushing and not in the shaft.
Depends on materials
and construction,
PTFE has coefficient
of friction ~0.05-0.35,
depending upon fillers
added
Good, provided
wear is low, but
some slack is
normally present
Low to very high Low to very high -
depends upon
application and
lubrication
Widely used, relatively high
friction, suffers from stiction
in some applications.
Depending upon the
application, lifetime can be
higher or lower than rolling
element bearings.
Rolling element bearing
Is also called an antifriction
bearing because the created
by this bearing is rolling
friction rather than sliding
friction creared by the plain
bearings.The rolling element
bearing is a cylinder
containing a moving inner ring
of stell balls or rollers.
Rolling coefficient of
friction with steel can
be ~0.005 (adding
resistance due to seals,
packed grease, preload
and misalignment can
increase friction to as
much as 0.125)
Good, but some
slack is usually
present
Moderate to high
(often requires
cooling)
Moderate to high
(depends on
lubrication, often
requires
maintenance)
Used for higher moment loads
than plain bearings with lower
friction

113. 4.1.3 Nomenclature of Bearing
Rolling bearings include radial and thrust bearing for radial and axial load, respectively,
and some bearing types which a design for combine radial and axial loads. Generally speaking ,
ball bearing a recommended for light to moderate load: roller bearing a recommended for heavy
load . There is nine basic bearings. Some of these basic types available in many variation : for
instance, cylindrical roller bearing may be obtain with one, two, or four row of roller .
Single row deep – groove ball bearings a generally available in nine different external
configuration. Taper roller bearing can some in more than 20 different configuration . The other
basic type do not come in large number of configuration, but it should be not that‘s all types of
rolling bearing are available in many design variants thus may vary greatly in internal design
depending on the manufacturer.
It is not within the scope of thus handbook to describe all the various design of rolling
bearing use in machinery but rather to alert maintenance personel to their existence . Details are
given in manufacturer catalog or by contacting the manufacturer directly.
Example : Code number of rooling bearing
Bearing Sizes
Figure 4.1.3 : Bearing Sizes
Each bearing has an inside diameter, outside diameter and width diameter in that order. Most
bearings are metric in size, but can also be imperial. On our site, each bearing shows its principal
dimensions.
Example for bearing Part Number
d = Inside diameter
D = Outside diameter
B/T = Width diameter

114. 4.1.4 Bearing Service Life
Basic life or L10 as defined in ISO and ABMA standards is the life that 90% of a sufficiently large
group of apparently identical bearings can be expected to reach or exceed. The median or average
life, sometimes called Mean Time Between Failure (MTBF), is about five times the calculated
basic rating life. Service life is the life of a bearing under actual operating conditions before it fails
or needs to be replaced for whatever reason. The so called specification life is generally a requisite
L10 basic rating life and reflects a manufacturer's requirement based on experience with similar
applications.
4.1.4.1 Calculating Loads
Engineers typically employ rolling-contact fatigue models that compare bearing load
ratings to applied dynamic and static loads as they impact service life and reliability. The basic
dynamic load rating covers dynamically stressed bearings that rotate under load. This rating,
defined in ISO 281, is the bearing load that results in a basic rating life or L10 of 1 million
revolutions. Dynamic loads should include a representative duty cycle or spectrum of load
conditions and any peak loads.
The basic static load rating applies to bearings that rotate at speeds less than 10 rpm, slowly
oscillate, or remain stationary under load over certain periods. Be sure to include loads of

115. extremely short duration (shock) because they may plastically deform contact surfaces and
compromise bearing integrity.
Basic catalog or simplified calculations typically ignore elastic deformations in the bearing,
housing, or machine frame, as well as moments produced in the bearing by shaft deflection. Such
calculations may assume loads are constant in magnitude and direction and act radially on a radial
bearing, or axially and centrically on a thrust bearing. Oftentimes, bearings in actual service see
simultaneous radial and axial loads. When the resultant of radial and axial loads is constant in
magnitude and direction, calculate an equivalent dynamic bearing load from:
P = XFr + YFa
where P = equivalent dynamic bearing load, lb; Fr = actual radial bearing load, lb; Fa = actual axial
bearing load, lb; X = radial load factor for the bearing; and Y = axial load factor for the bearing.
For single-row radial bearings, axial load influences P only when the ratio Fa ⁄ Fr exceeds a
certain limiting value. Conversely, even light axial loads are significant for double-row radial
bearings. The above equation also applies to spherical thrust bearings and other thrust types that
handle both axial and radial loads. Be sure to consult manufacturer catalogs for axial-radial thrust
bearings because designs can vary widely. For thrust ball bearings and other types that carry pure
axial loads, the equation simplifies to P = Fa, provided the load acts centrically.
4.1.4.2 Rating Life Equations
The equation from ISO 281 or the American Bearing Manufacturers Association (ABMA)
Standards 9 and 11 figures basic, nonadjusted rating life by:
L10 = (C ⁄ P)p in millions of revolutions
where C = basic dynamic load rating, lb; P = equivalent dynamic bearing load, lb; p = life-equation
exponent ( p = 3 for ball bearings; and p = 10/3 for roller bearings)
For bearings run at constant speed, it may be more convenient to express the basic rating life in
operating hours:
L10h = (1,000,000/60)nL10 where n = rotational speed, rpm
Predicted bearing life is a statistical quantity in that it refers to a bearing population and a given
degree of reliability. The basic rating life is associated with 90% reliability of bearings built by
modern manufacturing methods from high-quality materials and operated under normal conditions.
In practice, predicted life may deviate significantly from actual service life, in some documented
cases by nearly a factor of five.

116. Service life represents bearing life in real-world conditions, where field failures can result from
root causes other than bearing fatigue. Examples of root causes include contamination, wear,
misalignment, corrosion, mounting damage, poor lubrication, or faulty sealing systems.
On going advances in bearing technology and manufacturing processes continue to extend bearing
life and reduce sensitivity to severe operating conditions. Standard ISO 281 has developed in step
with these advances to predict service life more accurately. The latest version expands coverage to
include bearing material fatigue stress limits, and a factor for solid contamination effects on
bearing life when using various lubrication systems such as grease, circulating oil, and oil bath.
The equation calculates modified rating life at n% reliability Lnm in millions of revolutions at
constant speed by:
Lnm= a1aISOL10
where a1 = life-adjustment factor for reliability (1.0 for 90% reliability); and a ISO = manufacturer
life modification factor according to ISO 281.
Finding a ISO involves the use of a contamination factor that considers the lubrication system type,
cleanliness class, bearing size, and lubrication operating conditions as defined in ISO 4406. This
contamination factor, along with the ratio of the bearing fatigue load limit to the bearing equivalent
load limit, and the lubrication condition, determine a ISO. In general, better lubricant conditions
and lower equivalent loads lessen bearing life sensitivity to contamination levels. Conversely, high
loads and poor lubricant conditions raise bearing life sensitivity to contamination.
Figure 4.1.4.2 : Operating Regimes
4.1.5Shield and Seal Bearings
Self lubricating bearings must have seals or shields to keep oil or grease in, and protection against
contamination.Shields Close-fitting but nonrubbing thin washer.Protect bearing against all but very
small foreign particles and help retain lubrication.

117. 4.2 Friction , temperature and lubrication
4.2.1 Friction in Bearing Systems
The friction in a rolling bearing is made up of several components, (see table 4.2.1) . Due
to the large number of influencing factors, such as dynamics in speed and load, tilting and skewing
resulting from installation, actual frictional torques and frictional power may deviate significantly
from the calculated values.
Table 4.2.1: Frictional component and influencing factor
Frictional component Influencing factor
Rolling friction Magnitude of load
Sliding friction of rolling elements
Sliding friction of cage
Magnitude and direction of load
Speed and lubrication conditions, running-in
condition
Fluid friction (flow resistance) Type and speed
Type, quantity and operating viscosity of
lubricant
Seal friction Type and preload of seal
4.2.2 Relation between operating temperature with bearing friction
4.2.2.1 Friction
One of the main functions required of a bearing is thatit must have low friction. Under normal
operating conditions rolling bearings have a much smaller friction coefficient than the slide
bearings, especially starting friction.
Although the dynamic friction coefficient for rolling bearings varies with the type of bearings,
load, lubrication, speed, and other factors; for normal operating conditions, the approximate
friction coefficients for various bearing types are listed in Table 10.1.
4.2.2.2 Temperature rise
Almost all friction loss in a bearing is transformed into heat within the bearing itself and
causes the temperature of the bearing to rise. Bearing operating temperature is determined by the
equilibrium or balance between the amount of heat generated by the bearing and the amount of
heat conducted away from the bearing. In most cases the temperature rises sharply during initial

118. operation, then increases slowly until it reaches a stable condition and then remains constant. The
time it takes to reach this stable state depends on the amount of heat produced, heat
capacity/diffusion of the shaft and bearing housing, amount of lubricant and method of lubrication.
If the temperature continues to rise and does not become constant, it must be assumed that there is
some improper function.
Possible causes of abnormal temperature include bearing misalignment (due to moment
load or incorrect installation), insufficient internal clearance, excessive preload, too much or too
little lubricant, or heat produced from sealed units. Check the mechanical equipment, and if
necessary, remove and inspect the bear
4.2.3 Principle of bearing lubrication
Many bearings require periodic maintenance to prevent premature failure, although some such as
fluid or magnetic bearings may require little maintenance.
Most bearings in high cycle operations need periodic lubrication and cleaning, and may require
adjustment to minimise the effects of wear.
Bearing life is often much better when the bearing is kept clean and well-lubricated. However,
many applications make good maintenance difficult. For example bearings in the conveyor of a
rock crusher are exposed continually to hard abrasive particles. Cleaning is of little use because
cleaning is expensive, yet the bearing is contaminated again as soon as the conveyor resumes
operation. Thus, a good maintenance program might lubricate the bearings frequently but never
clean them.
4.2.3.1 Packing
Some bearings use a thick grease for lubrication, which is pushed into the gaps between the
bearing surfaces, also known as packing. The grease is held in place by a plastic, leather, or rubber
gasket (also called a gland) that covers the inside and outside edges of the bearing race to keep the
grease from escaping.
Bearings may also be packed with other materials. Historically, the wheels on railroad cars used
sleeve bearings packed with waste or loose scraps cotton or wool fiber soaked in oil, then later
used solid pads of cotton.
4.2.3.2 Ring oiler
Bearings can be lubricated by a metal ring that rides loosely on the central rotating shaft of the
bearing. The ring hangs down into a chamber containing lubricating oil. As the bearing rotates,
viscous adhesion draws oil up the ring and onto the shaft, where the oil migrates into the bearing to
lubricate it. Excess oil is flung off and collects in the pool again.
4.2.3.3 Splash lubrication
Some machines contain a pool of lubricant in the bottom, with gears partially immersed in the
liquid, or crank rods that can swing down into the pool as the device operates. The spinning wheels
fling oil into the air around them, while the crank rods slap at the surface of the oil, splashing it
randomly on the interior surfaces of the engine. Some small internal combustion engines

119. specifically contain special plastic flinger wheels which randomly scatter oil around the interior of
the mechanism.
4.2.3.4 Pressure lubrication
For high speed and high power machines, a loss of lubricant can result in rapid bearing heating and
damage due to friction. Also in dirty environments the oil can become contaminated with dust or
debris that increases friction. In these applications, a fresh supply of lubricant can be continuously
supplied to the bearing and all other contact surfaces, and the excess can be collected for filtration,
cooling, and possibly reuse. Pressure oiling is commonly used in large and complex internal
combustion engines in parts of the engine where directly splashed oil cannot reach, such as up into
overhead valve assemblies.[18] High speed turbochargers also typically require a pressurized oil
system to cool the bearings and keep them from burning up due to the heat from the turbine.
4.3 Mounting and dismounting of bearing.
Mounting and installation of a bearing depends on the type and its fitting practice. The
procedures covered are concerned with the proper methods and tools to accomplish installation of
pressed fitted bearing rings. Even though some of the tools and procedures used for mounting a
non-separable bearing are the same as those used for separable bearings, the methods covered here
are specifically for non-separable bearings.
If application requirements call for periodic inspections that require mounting and dismounting
of the bearings, the ease and methods required for these bearing procedures should be a bearing
selection consideration. Bearing mounting and removal is simplified by the use of bearings that
have separable races. Bearings such as cylindrical roller bearings, needle roller bearings, and
tapered roller bearings have separable races and should be considered for applications requiring
frequent inspections and removal of the bearings.
Since bearings with interference fits can be easily damaged during removal, precautions to
prevent damage during removal should be taken. Of course, if a bearing is to be discarded,
methods such as torch cutting can be used for bearing removal. If the bearing is to be reused or
checked for causes of damage, care needs to be taken during removal. To ease removal and avoid
damage to the bearing, the proper tools and methods need to be employed.
4.3.1 Mounting and dismounting equipments and tools.
Premature bearing failures are caused by poor fitting, usually using brute force, and being unaware
of the availability of the correct mounting tools and methods. Individual installations may require
mechanical, heat or hydraulic application methods for correct and efficient mounting. Professional
fitting, using specialized tools and techniques, is another positive step towards achieving maximum
machine uptime. Reliability variety of bearing installation and removal tools, hydraulic and manual
jaw pullers, bearing heaters, etc.
Tools/Equipments Uses

120. Hot Plate Bearing Heater
Mounting
Thread Hydraulic Nut
Mounting and Dismounting
Air-driven hydraulic pumps
Mounting and Dismounting
Standard Jaw Pullers
Dismounting
Induction Heaters
Dismounting

121. 4.3.2 Measuring equipment for bearing installation.
4.3.2.1 Waviness, roundness and form analyzer
Waviness on the bearing components can cause high vibration levels in most
applications. As the amplitude of these waves is as small as some nanometers, you can
understand the importance of measuring accuracy and resolution.
Waviness testers allow analysis of the waviness on the components and thus give the
production engineer a powerful tool to improve the production process. Because low noise and
vibration of bearings is becoming more important, there is a high demand on the measuring
accuracy and resolution.
i. Rotational measuring system with top concentricity precision, with electronics and
mechanics combined to perfection
ii. Air-bearing spindle with run out better than 0,02 µm and velocity-proportional
evaluation gives you direct indication of the waviness level of the component
iii. The calibration of this equipment is also very important and is performed to an
excellent standard.
Figure 4.3.2.1: Waviness, roundness and form analyzer
4.3.2.2 Noise and vibration tester
A noisy application might be caused by wavy bearing components, local defects in
the rings and balls or by dirt particles in the bearing. While basic requirements on a bearing
like stiffness, load capacity, speed limit and service life play a critical role in applications,
low noise and vibration are becoming even more important.
High tech analysis and measurement such as frequency analysis (FFT) and further
advanced analysis pinpoints faults. Spectral masks help to optimize the bearing
performance in the particular application.

122. Figure 4.3.2.2: Noise and vibration tester
4.4.2.3 Dimension measuring machines
Stricter process requirements cause tighter tolerances and higher output, resulting in
high demands on the measuring machine capability and time pressure when resetting
measuring equipment. In many cases, the resetting time of the measuring machines already
bottlenecks the process where there is still a need for thousands of master parts.
As documented on high precision automation technology, full in-line production control,
with minimized resetting times and closed loop post process features, reduce costs and give
you flexibility.
Figure 4.4.2.3: Dimension measuring machines
4.4.2.4 Optical inspection
SKF provides products and solutions for a wide variety of optical measurement and
optical inspection applications related to bearing manufacture. Primarily for rotation
symmetric components, such as balls, rollers, rings and bearings, industrial optical
inspection equipment from SKF keeps costs to a minimum while maximizing your
application.
In optical systems, the following basic physical principle is involved:
"The appearance of the product is different to what we have decided to be acceptable." That
appearance is dependent on three factors:
i. condition of the object - colour, roughness, etc.
ii. nature of the illumination - white light, coloured light, laser light, etc.
iii. properties of the sensors - matrix camera, line camera, single photo-detector, etc.

123. Figure 4.4.2.4: Optical inspection
4.4.2.5 Non destructive testing
The thorough inspection of components is a way to check that each component is
defect free, or complies with certain quality requirements to retain their usability. The
various NDT techniques include:
i. ultrasonic inspection
ii. Eddy current testing
iii. magnetic particle inspection
iv. resonant inspection
Figure 4.4.2.5: Non destructive testing
4.4.2.6 Gauges for bearing mounting
When checking features such as tapered seatings, roller set bores or outside diameters of
cylindrical roller bearings, conventional measuring methods and instruments are not always
suitable.
This gauge is specially designed to meet the measuring needs of cylindrical roller
bearings with a tapered bore. These gauges are also useful for other applications.
Ring gauges can be used to check the most common tapered seatings. Measurements can be
made quickly and accurately. While a ring gauge can be used only to check a tapered
seating for a particular bearing size, the taper gauges can be used for a range of diameters.
To precisely adjust the radial internal clearance or preload when mounting
cylindrical roller bearings with tapered bores, it is necessary to accurately measure the
roller set bore or outside diameter.

124. Figure 4.4.2.6: Gauges for bearing mounting
4.3.3 Concept of adjusting clearance during installation.
Selecting the correct bearing internal clearance and determining whether preload is needed for
a particular application is critical to obtaining the desired bearing performance.
4.3.3.1 Description of Internal Clearances
Bearing internal clearance is described as being either radial or axial and is the total
distance that either the inner or outer ring can be moved in the radial or axial direction while
the other ring is held stationary.
With only a few exceptions, bearing internal clearance is normally discussed in terms of radial
clearance. Matched pairs of angular contact ball bearings are specified in terms of axial internal
clearance. Also, when two single row tapered roller bearings are setup opposing each other, the
clearance value between the rows is an axial measurement.
Clearance prior to mounting is generally referred to as the original clearance. This initial
clearance value is what is provided in the bearing at the time of shipment.
After the bearing is fitted on a shaft and into housing, the original clearance is reduced due to
contraction or expansion of the rings and is called the residual clearance or mounted clearance.
Effective clearance is the residual clearance after taking into account changes from temperature
differentials within the bearing.
Operating clearance is defined as the effective clearance with the additional effect of elastic
deformations from application loading. Successful bearing performance depends on having the
appropriate ―operating clearance‖ to avoid premature bearing damage and reduced fatigue life.

125. Figure 4.3.3.1: Radial Clearance and Axial Clearance
4.3.3.2 Fit Selection Considerations
As previously pointed out, there are other operating conditions to consider in
addition to knowing which ring will be rotating when trying to determine the proper fits to
use. The operating conditions that should be considered when determining bearing ring fits
are the following:
i. Load characteristics
ii. Load magnitude
iii. Temperature effects
iv. Effect on bearing internal clearances
v. Finish of mating surface
vi. Shaft and housing material & section thickness
vii. Mounting design and fixed and float considerations
viii. Bearing type and size
4.3.4 Mounting and dismounting methods classification.
Proper installations of bearing such as a substantial impact shorten its lifecycle. With
proper installation of bearing significantly extended for the life of which is a positive impact on
maintenance costs. Incorrect installation can cause damages to the bearing and an early failure.
Incorrect adaption for the assembly can cause excessive wear and the early damage. To avoid
the above mentioned problems it is very important to select appropriate method and proper
manner bearing assembly.
4.3.4.1 Mechanical Installation
Mechanical or cold mounting is suitable for small to medium-sized bearings. Use
appropriate tools to prevent damage to bearings, other components and not the least injury to
persons.
4.3.4.2 Installation using heating
Installation by using heating means based on the induction and it is used in medium and
large bearings. By increasing the size of bearings also increase the force required for
assembly of the bearing. Due to the size of force are larger bearings very difficult to push
the shaft or casing. Pre-heating of the bearing or casing before installation is extremely
simplified. In assembly with heated bearing to a temperature that is 80 to 90 ° C above the
temperature of the shaft, which mounts bearings.
4.3.4.3 Installation using hydraulic
In this method, there is minimal risk of damage bearing, shaft and other components.
Despite the size and weight bearing requires very little effort which is required for
installation, while providing a safe working environment without significant risk injury to
employees. Principle of the hydraulic assembly technique consists of injecting the thin
layer of oil between the bearings and shaft, which greatly reduces friction and allows the
bearing assembly with the minimum necessary force. The method is not only useful for
bearings, but also in other mechanical components, which the classic method of assembly
would have been rather problematic.

126. 4.3.4.4 Mechanical removal
Mechanical removal is suitable for small to medium-sized bearings. Use appropriate
tools to prevent damages to bearings, other components and not the least injury to persons.
There are several types of downloads, allowing the dismantling of all types of bearings
under all conditions:
i. mechanical Downloads
ii. hydraulic Downloads
iii. Downloads for blind casings
4.4.4.5 Dismounting with the Heat
Dismantling with the heat is mainly suitable for bearings with close fitting. The use of
mechanical downloads could damage the shaft or bearing rings in this case, it requires more
power. By using special heaters there are significantly easier to dismantle and reduce the
chance of damage to components and body injury. The heaters for dismantling are basically
divided into:
i. heated rings
ii. induction heaters
4.3.4.6 Dismantling by Oil Injection
Oil injection is a common choice for major dismantling of bearings and other
components. Allows disassembly with a substantially lower power and significantly reduce
of possibility of damaging bearing, shaft and grounding. The basic principle of the method
is injecting oil down the certain viscosity between two surfaces, while between them the
pressure generated oil film and differentiate them. This method can reduce the necessary
force to dismantle the casing up to 90%.
4.4 Analyze bearing damage.
When a bearing is used under ideal conditions, it should meet or exceed its
predicted service life and will eventually be damaged by rolling fatigue. Damage from
rolling fatigue can occur prematurely if operating conditions are severe or the wrong
bearing was selected for the application. However, as indicated by the following
statements, the majority of premature bearing failures are caused by improper lubrication,
bearing mounting and handling issues.
If damage is found on a bearing during inspection, it is important to document the
bearing‘s operation history properly to identify the causes, even if the damage is very small.
Also, it is essential to examine not only the bearing but also the shaft, housing and
lubricant.
4.4.1 Bearing damage and failure symptoms.
Since there are many different failure modes and damage bearings will exhibit, the
following pages will review these and cover possible causes and preventive measures that

127. can be taken.
4.4.1.1 Flaking
Flaking is damage where material is removed in flakes from a surface layer of the
bearing raceways or rolling elements due to rolling fatigue. This failure mode is generally
attributed to the approaching end of bearing service life. However, if flaking occurs at
early stages of bearing service life, it is necessary to determine causes and adopt
preventive measures.
Figure 4.4.1.1: Flaking
4.4.1.2 Cracking, Chipping
Usually referred to as spalling is a fracture of the running surfaces and subsequent removal
of small discrete particles of material.
Figure 4.4.1.2: Cracking, Chipping
4.4.1.3 Brinelling, Nicks
Brinelling is a small surface indentation generated either on the raceway through plastic
deformation at the contact point between the raceway and rolling elements, or on the rolling
surfaces from insertion of foreign matter, when heavy load is applied while the bearing is
stationary or rotating at a low rotation speed. Nicks are those indentations produced directly
by rough handling as hammering.
Figure 4.4.1.3: Brinelling, Nicks

128. 4.4.1.4 Pear Skin, Discoloration
Pear skin is damage in which minute Brinell marks cover the entire rolling surface,
caused by contamination. This is characterized by loss of luster and a rolling surface that is
rough in appearance. In extreme cases, it is accompanied by discoloration due to heat
generation. This phenomenon is also commonly called frosting.
Discoloration is damage in which the surface color changes because of staining or
heat generation during rotation. Color change caused by rust and corrosion is generally
separate from this phenomenon.
Figure 4.4.1.4: Pear Skin, Discoloration
4.4.1.5 Scratch & Scuffing
Scratches are relatively shallow marks generated by sliding contact, in the same
direction as the sliding. This is not accompanied by apparent melting of material. Scuffing
refers to surface marks, which are partially melted due to higher contact pressure and
therefore a greater heat effect. Generally, scuffing may be regarded as an advanced case of
scratches.
Figure 4.4.1.5: Scratch & Scuffing
4.4.1.6 Smearing
Smearing is damage in which clusters of minute seizures cover the rolling contact
surface. Since smearing is caused by high temperature due to friction, the surface of the
material usually melts partially; and the smeared surfaces appear very rough in many cases.
Figure 4.4.1.6: Smearing

129. 4.4.1.7 Rust, Corrosion
Rust is a film of oxides, or hydroxides, or carbonates formed on a metal surface due to
chemical reaction. Corrosion is damage in which a metal surface is eroded by acid or alkali
solutions through a chemical reaction (electrochemical reaction such as chemical
combination and battery formation); resulting in oxidation. It often occurs when sulfur or
chloride contained in the lubricant additives is dissolved at high temperature. It can also
occur when water becomes entrapped in the lubricant.
Figure 4.4.1.7: Rust, Corrosion
4.4.1.8 Wear
Normally, wear on bearings is observed on sliding contact surfaces such as roller end
faces and rib faces, cage pockets, and cage riding lands. However, wear caused by foreign
material and corrosion can affect not only sliding surfaces but also rolling surfaces.
Figure 4.4.1.8: Wear
4.4.1.9 Fretting
Fretting occurs to bearings which are subject to vibration while in a stationary condition
or which are exposed to slight axial movements. It is characterized by rust-colored wear
particles. Fretting damage on the rotating ring is usually a clear indication of an improper
fit. Since fretting on the raceways often appears similar to brinelling, it is
sometimes called ―false brinelling‖.
Figure 4.4.1.9: Fretting

130. 4.4.1.10 Cage Damage
Since cages are made of low hardness materials, external pressure and contact with
other parts can easily produce dents and distortion. In some cases, these are aggravated and
become chipped and cracked. Large chipping and cracks are often accompanied by
deformation, which may reduce the accuracy of the cage itself and may prevent the smooth
movement of rolling elements. Also, if cage damage is observed, the bearing raceways
should be examined for misalignment, as even minor misalignment can cause cage
breakage.
Figure 4.4.1.10: Cage Damage
4.4.1.11 Creeping
Creeping is a phenomenon in which bearing rings move relative to the shaft or housing
during operation.
Figure 4.4.1.11: Creeping
4.4.1.12 Seizure
Seizure is damage caused by excessive heating in bearings.
Figure 4.4.1.12: Seizure
4.4.2 Observations for preventive maintenance.

131. 4.4.2.1 Flaking
Table 4.4.2.1: Flaking
4.4.2.2 Cracking, Chipping
Table 4.4.2.2: Cracking, Chipping

132. 4.4.2.3 Brinelling, Nicks
Table 4.4.2.3: Brinelling, Nicks
4.4.2.4 Pear Skin, Discoloration
Table4.4.2.4: Pear Skin, Discoloration
4.4.2.4 Scratch & Scuffing

133. Table4.4.2.4: Scratch & Scuffing
4.4.2.5 Smearing
Table 4.4.2.5: Smearing
4.4.2.6 Rust, Corrosion
Table 4.4.2.6: Rust, Corrosion
4.4.2.7 Wear

134. Table 4.4.2.7: Wear
4.4.2.8 Fretting
Table 4.4.2.8: Fretting
4.4.2.9 Creeping
Table 4.4.2.9: Creeping
4.4.2.10 Cage Damage

135. Table 4.4.2.10: Cage Damage
4.4.2.11 Seizure
Table 4.4.2.11: Seizure
4.4.3 Bearing maintenance procedure.
For properly identifying the cause of bearing damage in an application, the following
procedure and investigation is recommended:
i. Review service and maintenance records and any other previous data from bearing
monitoring equipment.
ii. Prior to bearing removal and inspection, a final noise and temperature check should be
performed and recorded.
iii. Create a sheet for documenting bearing and application inspection observations which
should include pertinent photos.
iv. Lubricant samples should be taken from bearings and surrounding areas including housing
and seals.
v. A sample of new unused bearing lubricant should also be collected.
vi. When the bearing is removed from the equipment, step 5 showm in the ‗bearing removal
methods‘ section of this book should be followed.
vii. If the bearing must be reomved from the shaft by pulling on the outer ring, mark position of
the balls on the inner ring so that the damage that is caused during disassembly can be
identified and not mistakenly attributed to an assembly problem.
viii. The machine components surrounding the bearings such as backing shoulders,
locknuts, and any sealing devices need to be inspected for damage and wear and then
documented on the inspection sheet.
ix. The shaft and housing should be measured for bore and OD sizes, roundness and taper.

136. x. After the bearing has been removed and cleaned, all markings and part numbers should be
recorded.
xi. If a bearing is to be returned to the manufacturer for analysis, do not clean the lubricant
from the bearing.
xii. The general condition of the bearing should be noted and recorded, with specific
attention to the condition of the rolling elements and raceways.
xiii. If further analysis of the bearing damage is required or a metallurgical check may be
needed, a preservative oil should be applied to the bearing prior to repackaging and
shipment.
xiv.
Question
1. Identify THREE (3) thermal methods and THREE (3) mechanical methods of mounting
bearings.
2. Identify FOUR (4) common causes for bearing failure.
References
.
1. Riccardo Manzini, Alberto Regattieri (2010) Maintenance For Industrial Systems,
Springer Dordrecht Heildelberg London, New York, ISBN978-1-84882-574-1

137. 5
Engr.Mohamed Hamdan Bin Mohamad Ibrahim (PUO)
Zaini Bin Ashaari (PMM)
Hajah Norbaya Binti Mhd Simin (POLISAS)
5.1 Clutches and brakes principle.
5.1.1 Function of a clutch and brakes.
The function of a clutch is to engage or disengage a machine (or machine
component) without starting or stopping the driver. Different types of clutches can
also provide the following:
a. Slower, smooth engagement and disengagement under full speed.
b. Quick engagement and disengagement.
c. Overload protection by limiting the maximum torque loads.
d. Prevention of accidental machine reversal.
Brakes are actually clutches with one side locked down so when the
clutch/brake engages the rotating shaft stops.
5.1.2 Types of clutches:
a. Mechanical
b. Electrical
c. Hydraulic
a. Mechanical clutches
i. Friction Clutches
- Widely used in industry (i.e. automotive industry).
- Can be actuated or operated manually, pneumatically or hydraulically.
CLUTCHES AND
BRAKES
Learning Outcomes
Upon completion of this chapter, students should be able to:-
1. Describe clutches and brakes principle.
2. Develop clutches and brakes maintenance procedure

138. - Use a lined metal of fibrous metal mounted between two steel plates as a
means of transferring motion between two mechanical components.
- Transferring of motion occur when the separate plates are bought into
contact with each other.
- The travel of the friction plates is very small compared to the jaw clutches.
- The driven portion of a friction clutch is frequently supported by bearings on
the driving hub.
ii. Jaw Clutches
- Usually used on slow speed applications.
- Motion for engaging and disengaging the clutch is accomplished with a
shifting arm.
- The shifting arm are usually has the fulcrum or pivot point located at one
end of the arm with the operating handle located at the other end.
iii. Centrifugal Clutches
- Friction type centrifugal clutches are commonly found in applications where
it is desirable to have either no load starting or protection against overload.
- Can also function as couplings or can be mounted directly to V-belt.
- In operation, centrifugal clutches start from a disengaged or at rest position.
- Centrifugal clutches become positively engaged at no time during operation.
iv. Overrunning Clutches
- Also known as one-way clutches.
- Frequently used on machine where the driving motor or media requires
protection.
- Prevent overspeeding of the drive by allowing free rotation of the drive
component.
- Designed to permit rotation of the driving force in the forward direction
only.
- To accomplish this overrunning action, two common type of mechanism are
used rollers and sprags.
- Rollers running on flat surface inside round housing while sprags positioned
between two circular surfaces. Sprags are irregular or can shaped pieces.
- During operation, sprags are wedged between the inner and outer hubs.
v. Torque Limiting Clutches
- Used on any number of different pieces of equipment or also used with
roller chain type coupling.
- The driven half of the clutch is always engaged during startup and only slip
when overloaded.
vi. Tooth Clutches
- Used pneumatic of hydraulic actuating cylinder to operate.
- The mating surface of a tooth clutch is constructed with notches or
serrations.
- In operation, the notched surfaces contact each other motion is transmitted
from the driving to the driven halves of the clutch.

139. b. Hydraulic Clutches
i. Fluid Clutches
- Widely used in industry because of their ability to start under heavy
loads and absorb shock loads.
- Also used to provide a smooth flow of power to the driven side of a
machine. (Also known as fluid coupling).
- The driven half of a fluid coupling is actuated by the hydraulic fluid.
- The driving half (pump/impeller) and driven half (turbine) will
rotate at the same speed during operation.
c. Electric Clutches
- Used where intermittent motion is required especially to start and
stop the drive motor on short time cycles.
- A magnet or coil is mounted on a driven component or machine
while an armature plate is mounted on the driving motor or shaft.
- When the two parts are de-energized, no contact or action takes
place between them, even though the motor the motor may be
running.
- When an electric current is introduced into the magnet or coil, a
magnetic field is set up causing the armature and the coil to draw
together.
- This action then couples the two halves electrically and physically
causing them to rotate as one piece.
5.1.3 Assemble and dissemble clutch and brake
a. Dissemble clutch and brake
i. Remove the engine from the car.
Note: The pressure plate assembly and clutch disk remain on the
flywheel when you remove the engine. The clutch release
(throw-out) bearing and related parts stay in the transmission.

140. ii. If the old pressure plate is to be reused, scribe or paint
alignment marks on the pressure plate and the flywheel to ensure
proper realignment of the pressure plate during reassembly.
iii. Hold the pressure plate securely and completely, then loosen the
pressure plate-to-flywheel bolts by turning each bolt only a little
at a time. Work in a criss-cross pattern until all spring pressure
is relieved. Then remove the bolts, followed by the pressure
plate and the clutch disc.
Caution: The pressure plate is under a great deal of spring pressure. If
you work your way around the plate, removing each bolt one
at a time, it will warp.
iv. Clean the friction surface on the flywheel and inspect it for
wear, cracks, heat checking, grooves, and other obvious defects.
Alternating brigt and dull areas indicate a warped plate. A
machine shop can machine the surface flat and smooth (highly
recommended, regardless of the surface appearance). Light
glazing can be removed with medium grit emery cloth.
v. Inspect the diaphragm spring fingers for excessive wear and
make sure they are not distorted.
vi. Shake the pressure plate assembly and verify that the diaphragm
spring, which should be under tension, does not rattle. If the
pressure plate is defective in any way, replace it.
vii. If you will be reinstalling the engine you removed, clean the
flywheel and pressure plate friction surfaces with lacquer
thinner or acetone.
Caution: DO NOT use oil or grease on these surfaces or on the clutch
disk lining. And clean your hands before handling the parts.
viii. Inspect the clutch release (throw-out) bearing. If it feels gritty
when you turn it, or if it has been making noise, replace it.
Never wash the bearing in solvent since this will remove the
factory-installed lubricant. If the bearing is unserviceable,
replace per the procedure.

141. ix. Inspect the lining on the clutch disk for wear. There should be at
least 2mm of friction material remaining above the rivet heads.
x. Check the clutch disk for loose rivets, distortion, cracks, broken
springs and other obvious damage.
Note: As mentioned above, ordinarily the clutch disk is routinely
replaced, so if in doubt the condition, replace it with a new one.
If you're planning to re-use the old clutch disk, it's a good idea to
check it for run out.
xi. Carefully inspect the splines inside the hub of the clutch disk
and the splines on the transmission input shaft. They must not be
broken or distorted. Lubricate the splines in the disk hub and the
splines on the input shaft with graphite or molybdenum disulfide
powder (Rob's last replacement clutch plate came with a tiny
tube of special "spline" grease to be smeared sparingly on the
splines).
xii. Verify that the clutch disk slides freely on the drive shaft splines
without excessive radial play. If the clutch disk is in any way
unserviceable, replace it.
Note: You're probably replacing the clutch disk anyway, but if the
splines on the input shaft are damaged, you'll have to replace the
input shaft as well.
Note: If you are replacing the main oil seal, remove the flywheel at this
point and replace the clutch after the flywheel has been
reinstalled.
b. Reassemble:
i. Install the flywheel, if removed.
ii. Clean the flywheel and pressure plate friction surfaces with
lacquer thinner or acetone.
Caution: DO NOT use oil or grease on these surfaces or on the clutch
disk lining. And clean your hands before handling the parts.
iii. Position the clutch disk and pressure plate against the flywheel
with the clutch held in place with an alignment tool (the best
alignment tool is an old input shaft, or there is a commercially-
available inexpensive one made of plastic).
Note: Clutch Pilot Tool - Using the clutch alignment tool can take a lot
of the headache out of installing an engine. Instead of eyeballing
to see if the clutch is centered, simply install the clutch
alignment tool into clutch disc, and tighten the pressure plate (a
turn per bolt, rotate around). The tool will keep the clutch disc
centered so the engine goes onto the transmission easier. After
you are finished, simply pull the tool out, clean, and save for the
next time you need it!
Note: Lacking a centering tool, you can just get down to flywheel

142. height and "eyeball" it. The worst that can happen if it's not
exactly centered is that the last inch or so of engine installation
might take a little more shoving.
iv. Make SURE the clutch disk is installed properly (most
replacement clutch plates will be marked "flywheel side" or
something similar. If not marked, install the clutch disk with the
damper springs towards the transaxle.
v. If you're reusing the old pressure plate, make sure the marks you
made on the pressure plate and the flywheel are matched up.
vi. Install a clutch alignment tool into the center of the clutch disc
you intend to use. With the clutch disc on the alignment tool,
install the tool into the end of the crankshaft. Make sure that the
alignment tool extends through the splined hub and into the
needle bearing in the gland nut. Wiggle the tool up-down and/or
side-to-side as needed to bottom the tool into the gland nut.
vii. Make sure that the clutch disc is against the flywheel, then install
the pressure plate.
viii. Loosely start the six mounting bolts in the flywheel. Tighten
them "crosswise", back and forth across the plate to prevent
distorting the cover. After all the bolts are snug, torque them first
to about 10 ft-lbs and finally to 18 ft-lbs.
ix. Center the clutch disk by ensuring the alignment tool extends
through the splined hub and into the needle bearing in the gland
nut. Wiggle the tool up-down and/or side-to-side as needed to
bottom the tool into the gland nut.
x. Loosely install all of the mounting bolts. Tighten them
"crosswise", back and forth across the plate to prevent distorting
the cover. After all the bolts are snug, torque them first to about
10 ft-lbs and finally to 18 ft-lbs.
xi. Install the clutch release bearing if removed. Be sure to lubricate
the bore of the release bearing and the outer surface of the central
guide sleeve with high-temperature grease, and apply multi-
purpose grease to the contact areas of the forks on the release
shaft.
xii. Reinstall the engine in accordance with our Engine Installation
Procedure.
xiii. Adjust the clutch pedal free play in accordance with our Clutch
Cable Adjustment Procedure.
5.2 Clutches and brakes maintenance procedure
5.2.1 Checklist clutches and brakes maintenance, symptoms and record observations for
preventive maintenance
i. Improper adjustment of clutch or brake: The clutch or brake may not be
fully engaging. Follow the manufacturer‘s adjustment procedures.

143. ii. Oil or contaminant on friction surfaces: Clean or replace the surfaces.
iii. Worn out friction components: Check the components to see if they are
within tolerances. Replace them if necessary.
iv. Worn linkage or parts used in engaging clutch or brake: Sometimes
adjustment is adequate to compensate for wear. Check for obstruction and
corrosion on moving parts. Clean or replace the parts as necessary. Check
lubrication, and relubricate if required.
v. Too much torque: This may be because an increased load exceeds design
capacity or because of poor initial selection of a clutch or brake. Check the
machine to determine if the increased load is temporary or permanent.
Repairing or servicing a machine may reduce torque to acceptable levels. If
not, the clutch or brake should be replaced with one designed for the
increased torque loads required.
vi. High-frequency cycling or high-inertia loads: Generally, these cases of
excessive heat can be solved only by changing to a clutch or brake with
greater heat-dissipation ability. Sometimes a fan or blower may be used to
increase air flow, thus cooling equipment. Shortening the slipping time
during start-up can also reduce heat. Less slippage means less heat, but make
sure that engagement is not so sudden that severe shock loads are created in
the machine. Engaging clutches under the lightest possible start-up loads is
always recommended.
With any type of clutch or brake, the following are generally recommended:
i. The clutch or brake should always be the correct size for the application.
ii. Heat dissipation should always be adequate to ensure long life and low
maintenance.
iii. Lubrication, if required, should be done on a periodic, regular schedule.
iv. Components should be checked regularly for adjustment and wear.
v. Clutches and brakes should be kept clean and free from debris whenever
possible.

144. 6
Abd.HafiBin Ismail (PKB)
Aravinthan a/l Yelumalai (PMZA)
Mohammad ZainalAkmal Bin Ismail (POLISAS)
6.0 PUMPS,VALVESANDCOMPRESSOR
6.1 Understand pumps concepts.
Irrigation pumps lift water from an existing source, such as surface or groundwater to a higher
level.
They have to overcome friction losses during transport of the water and provide pressure for
sprinkler and drip irrigation
Irrigation pumps are mechanical devices which use energy from electrical or combustion motors
to increase the potential and (or) kinetic energy of the irrigation water.
Pumps are used in irrigation systems to impart a head to the water so it may be distributed to
different locations on the farm and used effectively in application systems.
The key requirement in pump selection and design of pump systems for typical irrigation
installations is that there is a correspondence between the requirements of the irrigation system
and the maximum operating efficiency of the pump
6.1.1 List application of pumps.
Pumps are used throughout society for a variety of purposes. Early applications includes the use
of the windmill or watermill to pump water. Today, the pump is used for irrigation, water supply,
gasoline supply, air conditioning systems, refrigeration (usually called a compressor), chemical
movement, sewage movement, flood control, marine services, etc.
6.1.2 Classify types of pumps based on it’s principle.
iv. Positive displacement
v. Rotor dynamic
i. A Positive Displacement Pump has an expanding cavity on the suction side of
the pump and a decreasing cavity on the discharge side. Liquid is allowed to flow
into the pump as the cavity on the suction side expands and the liquid is forced out
of the discharge as the cavity collapses. This principle applies to all types of
Positive Displacement Pumps whether the pump is a rotary lobe, gear within a
gear, piston, diaphragm, screw, progressing cavity, etc.
There are three main classifications of Positive Displacement Pumps
PUMPS,VALVESAND
COMPRESSOR
Learning Outcomes
Upon completion of this chapter, students should be able to:-
1. Understandpumpsconcepts.
2. Understand valve concepts
3. Understandcompressor concepts.

145. a. Rotary Positive Displacement Pump
b. Reciprocating Positive Displacement
ii. Rotor dynamic pumps are kinetic machines in which energy is continuously
imparted to the pumped fluid by means of a rotating impeller, propeller, or rotor.
The most common types of rotor dynamic pumps are centrifugal (radial), mixed
flow, and axial flow pumps.
These pumps are based on bladed impellors which rotate within the fluid to impart a tangential
acceleration to the fluid and a consequent increase in the energy of the fluid. The purpose of the
pump is to convert this energy into pressure energy of the fluid to be used in the associated piping
system.
Centrifugal pumps use bladed impellers with essentially radial outlet to transfer rotational
mechanical energy to the fluid primarily by increasing the fluid kinetic energy (angular momentum)
and also increasing potential energy (static pressure). Kinetic energy is then converted into usable
pressure energy in the discharge collector.
There are three main classifications of rotodynamic pumps
c. Radial Flow (Centrifugal Pumps)
d. Mixed Flow (Screw )Pumps
e. Axial Flow (Propeller) Pumps
6.1.3
Assembleanddisassemblepumpasapractical.Asaexamplescomponentscanbeuseiscentrifug
al pump.
Disassembly pump
1. Unloose the screws of fan cover and
remove it.
2. Remove the fan by means of a
screwdriver.

146. 3. Remove the plugs from the pump
casing
4. Using a bench vice lock the pump from
the motor shaft then release the preload
screws as shown in the picture.
5. Remove the motor holder.

150. 6.1.4 Developed check list pumps maintenance, symptoms and record observations for
preventive maintenance.
Pump Maintenance Concept
Poor maintenance can cause undue wear and tear of fast moving parts, and premature failure of
the equipment. Such premature failure or breakdown causes immense hardship to the consumers
and staff, and avoidable increase in repair cost. The shortcomings in maintenance can also result
in increase in hydraulic and power losses and low efficiency. Inefficient running of the pump
increases burden of power cost. Importance of preventive maintenance, therefore, need not be
overstressed.

151. Appropriate maintenance schedule and procedure need to be prescribed for all electrical and
mechanical equipment based on manufacturers’ recommendations, characteristics of the
equipment, site and environment conditions i.e. temperature, humidity, dust condition, etc. The
maintenance schedule also needs to be reviewed and revised in the light of experience and
analysis of failures and breakdown at the pumping station. The preventive maintenance schedule
shall detail the maintenance to be carried out at regular intervals i.e. daily, monthly, quarterly, half
yearly, annually etc. or operation hours. The schedule shall also include inspections and tests to
be performed at appropriate interval or periodicity.
Check List Pump Maintenance, Symptoms and Record Observation
For Preventive Maintenance
(a) Routine observations of irregularities
The pump operator should be watchful and should take appropriate action on any irregularity
noticed in the operation of the pumps. Particular attention should be paid to following irregularities.
i. Changes in sound of running pump and motor
ii. Abrupt changes in bearing temperature.
iii. Oil leakage from bearings
iv. Leakage from stuffing box or mechanical seal
v. Changes in voltage
vi. Changes in current
vii. Changes in vacuum gauge and pressure gauge readings
viii. Sparks or leakage current in motor, starter, switch-gears, cable etc.
ix. Overheating of motor, starter, switch gear, cable etc.
(b) Record of operations and observations
A log book should be maintained to record the hourly observations, which should cover the
following items.
i. Timings when the pumps are started operated and stopped during 24
hours.
ii. Voltage in all three phases.
iii. Current drawn by each pump-motor set and total current drawn at the
installation.
iv. Frequency.
v. Readings of vacuum and pressure gauges.
vi. Motor winding temperature.
vii. Bearing temperature for pump and motor.
viii. Water level in intake/sump.
ix. Flow meter reading.
x. Any specific problem or event in the pumping installation or pumping
system (burst in pipeline, tripping or fault, power failure).
Pump Maintenance Procedure
Daily Maintenance
• Clean the pump, motor and other accessories.
• Check coupling bushes/rubber spider.
• Check stuffing box, gland etc
Monthly Maintenance

152. i. Check free movement of the gland of the stuffing box, check gland packing
and replace if necessary.
ii. Clean and apply oil to the gland bolts.
iii. Inspect the mechanical seal for wear and replacement if necessary.
iv. Check condition of bearing oil and replace or top up if necessary.
Quarterly Maintenance
i. Check alignment of the pump and the drive. The pump and motor shall be
decoupled while correcting alignment, and both pump and motor shafts
shall be pushed to either side to eliminate effect of end play in bearings.
ii. Clean oil lubricated bearings and replenish with fresh oil. If bearings are
grease lubricated, the condition of the grease should be checked and
replaced/replenished to the correct quantity. An anti-friction bearing should
have its housing so packed with grease that the void space in the bearing
housing should be between one third to half. A fully packed housing will
overheat the bearing and will result in reduction of life of the bearing.
iii. Tighten the foundation bolts and holding down bolts of pump and motor
mounting on base plate or frame.
iv. Check vibration level with instruments if available; otherwise by observation.
v. Clean flow indicator, other instruments and appurtenances in the pump
house.
6.2 Understand valve concept.
A valve is a device regulates directs or controls the flow of a fluid (gases, liquids, fluidized solids) by
opening, closing.
6.2.1 Application of valves
 Gas system
 Crude oil industry
 Refinery plant
6.2.2 Classify types of valves.
Common valve type in usage.
 Ball valve
 Butterfly valve
 Gate valve
 Globe valve
Figure 6.2.1 Ball valve

153. Figure 6.2.2 Butterfly valve
Figure 6.2.3 Gate valve
Figure 6.2.4.Globe Valve
Valves can be categorized into the following basic types:
 Ball valve, for on/off control without pressure drop, and ideal for quick shut-off, since a 90° turn
offers complete shut-off angle, compared to multiple turns required on most manual valves.

154.  Butterfly valve, for flow regulation in large pipe diameters.
 Gate valve, mainly for on/off control, with low pressure drop.
 Globe valve, good for regulating flow.
Characteristic of valve.
Ball Valve
Ball valves are devices use a ball to stop and start the flow of fluid. As the valve stem turns to the open
position, the ball rotates to a point where part or the entire hole machined through the ball is in line with
the valve-body inlet and outlet. This allows fluid to pass through the valve. Ball rotates so that the hole is
perpendicular to the flow path, the flow stops. Most ball valves are quick-acting and require a 90-degree
turn of the actuator lever to fully open or close the valve.
Figure
6.2.5 Butterfly valve function.
The butterfly valve (figure 6.2.6) has a disk that rotates about a central shaft or stem. When the valve is
closed, the disk face is across the pipe and blocks the flow. Butterfly valve seat consist of a bonded
resilient liner, a mechanically fastened resilient liner, an insert-type reinforced resilient liner, or an integral
metal seat with an O-ring inserted around the edge of the disk.As shown in Figure 13.4, both the full open
and the throttled positions permit almost unrestricted flow. Therefore, this valve does not induce
turbulent flow in the partially closed position. While the design does not permit exact flow-control
capabilities, a butterfly valve can be used for throttling flow through the valve. In addition, these valves
have the lowest pressure drop of all the conventional types.

155. Figure 6.2.6.Butterfly valve function.
Gate valve
Gate valves are used straight line, laminar fluid flow, and minimum restrictions are needed. These valves
use a wedge-shaped sliding plate in the valve body to stop, throttle, or permit full flow of fluids through
the valve. When the valve is wide open, the gate is completely inside the valve bonnet. This leaves the
flow passage through the valve fully open with no flow restrictions, allowing little or no pressure drop
through the valve. Gate valves are not suitable for throttling the flow volume unless specifically authorized
for this application by the manufacturer. They generally are not suitable because the flow of fluid through
a partially open gate can cause extensive damage to the valve.
Figure 6.2.7.Gate valve function.

156. Globe valve
A disk attached to the valve stem controls flow in a globe valve. Turning the valve stem until the disk is
seated closes the valve. The edge of the disk and the seat are very accurately machined to provide a tight
seal. It is important for globe valves to be installed with the pressure against the disk face to protect the
stem packing from system pressure when the valve is shut. While type of valve is commonly used in the
fully open or fully closed position, it also may be used for throttling.
Figure 6.2.8 Globe valve function
6.2.3 Determine valve maintenance concept.
Ball Valve
There are specific cleaning agents that should be used with the valve parts that are made of plastic,
rubber, and metal. The appropriate cleaning agent should be used to avoid reaction of the cleanser with
the parts. This can prevent any damages that can be brought by corrosive reactions. Cleansing sprays
made of gas perfectly works for metal parts where gas is the working medium. Alcohol or water or a
mixture of the two can be applied on non-metal parts. However, there are manufactured cleansers that
are especially formulated for valve parts.
Butterfly Valve
Following proper directions and instructions is and will always be a nice thing to do, even in installing a
butterfly valve inside the house. No kidding. This valve is widely used in day-to-day life such as in the
carburettor of a car. These valves are mainly used in controlling a certain object, in the case of a
carburettor, and then the entrance of air in the car is being decreased or increased through the use of the
valve. Simply put, this is used to regulate the flow which in this case, is the air. Due to this high end
function, proper and constant maintenance of this valve is a must. This valve is operated similar to that of
a ball valve.
Gate valve
The proper maintenance of a gate valve, or any valve for that matter, is important in ensuring that it will
last for many years and work as efficiently as it should. Thinking that it can simply be installed and left
alone afterwards is the beginning of the end since the time will definitely come that the valve will either
have to be repaired or totally replaced due to lack of maintenance. So, if you want to spare yourself a few
headaches and several dollars in repair or replacement costs, learn how to maintain your gate valves
effectively.

157. 6.2.4 Developed check list valve maintenance symptoms and record observation for preventive
maintenance.
Control/Shut-OffValve- Inspection Form
GeneralInformation:
DateofSiteVisit: UnitNo._
PlantName:
Source/sofdata:
ValveManufacturer: _Age ofValve: ___
SizeofValve: SizeofPenstock
SystemPressure(PSI):
Control/Shut-OffValveDescription:_ __
Maintenance History/MajorRepairsDescription:
Control/Shut-OffValve:
ValveManufacturer/Model:
RatedOperatingPressure:
Additionspecificationdata:

158. Valve Operator:
Make:_ Model: _
Additionspecificationdata:
4

159. Control/Shut-OffValveCheck List
Topic Yes No N/A Comments/Details
Maintenance&MajorRepairHistory
Arethereplantpreventivemaintenanceprocedures for the
Control/Shut-off Valve? Aretheyroutinelycarriedout?
Has therebeen anyvalveand/orpenstockrepair?
Has theValvebeenrebuilt?
Has thevalveoperator beenrebuilt?
Ifpartsof valverequire lubrication,arethererecordsof
lubricantapplication?
Haveallplantrecords regardingvalverepairs,operating
conditions, etc. beenrequested/gathered?
5

160. Control/Shut-OffValveCheck List- Continued
Topic Yes No N/A Comments/Details
Equipment ConditionAssessment
Whatisconditionof theexteriorofthevalve?
CantheinterioroftheValvebeaccessed?
Whatisthe conditionoftheinteriorof thevalve?
Whatisthe conditionofthe valveoperator?
Aredifferentialpressureindicatorsortransmitterspresent?
Aredifferentialpressureindicatorsortransmitters
operational?

161. Control/Shut-OffValveCheck List- Continued
Topic Yes No N/A Comments/Details
Equipment ConditionAssessment-Continued
Isthereavalvepositionindicator?
Doesthevalvepositionindicatorfunctioncorrectly?
Localand/or remote?
Havevalvemalfunctions been notedasthe causeof unit
outagesor unitderatings? If so, howmanymegawatthours
lost(MWHL)havebeenattributedtovalves?
Doesthevalvehavepackingleaks?
Doesthevalvehaveflange gasketleaks?
Isthevalveinsulated?
Ifso, doestheinsulationcontainasbestos fiber?

162. Control/ShutoffValveDataCollectionSheet
Topic DataInput

163. Symptom and corrective action for ball valve.
SYMPTOMS REASON ACTION

164. Symptom and corrective action for butterfly valve.
SYMPTOMS REASON ACTION

165. Symptom and corrective action for globe valve.
SYMPTOMS REASON ACTION

166. 6.3 Compressor Concept
Introduction
This machine is broadly use in our everyday live where we can find them in our homes
and workplaces, and in almost any form of transportation we might use. Compressors serve in
refrigeration, engines, chemical processes, gas transmission, manufacturing, and in just about
every place where there is a need to move or compress gas.
Compressor in general
In general compressors are machines that are used to compress air or gas. It also a
machine that handling fluid that capable efficiently transferring energy to the fluid medium so
that it can be delivered in large quantities at desired pressure condition. The working principles
are the same with pump working principle where both can also transfer it through a pipe. It also
is mechanical devices which convert the air into energy, this energy can then be used to run
machinery and perform various functions. Compression is achieved through the reduction of the
volume that the gas (or air) occupies. As a side effect of the minimization of volume, the
temperature of air or gas increases. The higher the compression ratio, the higher the temperature
tends to rise.
6.3.1 List of Application
Compressors are widely used by various types of industries and home appliance that
depend on the power of compressed gas or fluid to power manufacturing processes in the
industries. List the application of compressor such as:-
a) Air conditioners for car and home
b) Air pumps
c) Home and industrial refrigeration
d) High pressure car washes
e) Hydraulic compressors for industrial machines
f) Air compressors for industrial manufacturing
g) Chemical/petrochemical plants
h) ethylene plants
i) Gas lift/gas gathering
j) Gas injection/transport
k) LNG facilities
l) Gas to liquids
m) Ammonia plants
n) Power generator

167. ries
6.3.2 Type of compressor
It can be divided into two main categories:-
i. Dynamic
ii. Positive displacement
Figure 6.3.1 type of compressor
6.3.3 Principle and Characteristic of Compressor
i) Dynamic
This type of compressors uses the phenomenon of velocity to generate energy. It happens
by creating high speed energy through a rapidly moving piece. This fast moving piece then
propels the basic unit of the air compressor to generate power which is then used for mechanical
purposes. The dynamic compressor is characterized by rotating impeller to add velocity and
pressure to fluid. Compare to positive displacement type compressor, dynamic compressor are
much smaller in size and produce much less vibration. Although the dynamic air compressors are
very useful they are not as common as the positive displacement compressors and their use is
mostly restricted to various industries and is not used at homes. It is widely used in chemical
and petroleum refinery industry for specifies services. They are also used in other industries such
COMPRESSOR
Dynamic Centrifugal
Positive
Displacement
Rotary
Reciprocating

168. as the iron and steel industry, pipeline booster, and on offshore platforms for reinjection
compressors.
a) Centrifugal Compressor
Figure 6.3.2 centrifugal pumps
A centrifugal compressor is a ‗‗dynamic‘‘ type of compressor. It has a continuous flow of
fluid which receives energy from integral shaft impellers. In a centrifugal compressor the
mechanical energy is increased by centrifugal action. The gas enters the suction eye of a high
speed rotary element called the impeller which carries radial vanes integrally cast in it. As the
impeller rotates, the blades of the impeller force the gas outward from the center the impeller to
the outer rim of impeller, the increase in velocity of the gas creates a flow pressure area at the
eye of the impeller. The gas at the outer rim of the impeller is forced in to a passage way called a
diffuser where the velocity decreases in the pressure of the gas. The maximum pressure rise for
centrifugal compressor mostly depends on the rotational speed (rpm) of the impeller and the
impeller diameter. But the maximum permissible speed is limited by the strength of the structural
materials of the blade and the sonic velocity of fluid and it will leads into limitation for the
maximum achievable pressure rise.
Advantages

169. a) Reliable
b) Compact
c) Robust
d) High reliability, eliminating the need for multiple compressors and installed standby
capacity.
e) For the same operating conditions, machine prices are lower for high volume flow rates.
f) Less plot area for installation for a given flow rate.
g) Machine is small and light weight with respect to its flow rate capacity.
h) Installation costs are lower due to smaller size
i) Low total maintenance costs
j) When a turbine is selected as a driver, the centrifugal compressor's speed level allows
direct drive thereby minimizing equipment cost, reducing power requirements, and
increasing unit reliability.
k) Flow control is simple, continuous, and efficient over a relatively wide flow range.
l) No lube oil contamination of process gas.
m) Absence of any pressure pulsation above surge point.
n) Can reach pressure up to 1200 psi.
o) Completely package for plant or instrument air up through 500 hp.
p) Does not require special foundations
Disadvantages
a) Lower efficiency than most positive displacement types for the same flow rate and
pressure ratio.
b) Due to recycle not efficient below the surge point.
c) Very sensitive to changes in gas properties, especially molecular weight
d) Not effective for low molecular weight gases. The pressure ratio capability per stage is
low, tending to require a large number of machine stages, hence mechanical complexity.
e) High initial cost
f) Complicated monitoring and control systems
g) High rotational speed require special bearings and sophisticated vibration and clearance
monitoring
h) Specialized maintenance considerations

170. ii) Positive Displacement Compressor
Positive displacement compressors types deliver a fixed volume of air at high pressures
condition. It can be divided into two types which are rotary compressors and reciprocating
compressors. In this type of compressor a certain inlet volume of gas is confined in a given space
and subsequently compressed by reducing this confined space or volume. At this elevated
pressure, the gas is expelled into discharge piping or vessel system.
a) Rotary Compressor
Figure 6.3.3 Rotary Compressor
Rotary compressor is a group of positive displacement machines that has a central,
spinning rotor and a number of vanes. It also generally classified as screw compressor, vane type
compressor, and lobe and scroll compressor. The difference between each type is their rotating
device.
This compressor gains the pressurizing ability from a spinning component. These types
of compressor are compact, relatively inexpensive, and require a minimum of operating attention
and maintenance. The compressor increased the pressure of the gas by trapping it between vanes

171. which reduce the volume when the impeller rotates around an axis eccentric to the casing as
show in the figure 6.3.4 below:
Figure 6.3.4 Rotary Compressor Gas Compressing Principle
The volume can be varied by changing the speed or by bypassing or wasting some of the
capacity of the machine. The discharge pressure will can be control with the resistance on the
discharge side of the system.
Advantages
a) Simple design
b) Low to medium initial and maintenance cost
c) Two-stages design provide good efficiencies
d) Easy to install
e) Few moving parts
Disadvantages
a) High rotational speed
b) Shorter life expectancy than any other designs
c) Single-stage designs have lower efficiency
d) Difficulty with dirty environment

172. b) Reciprocating compressor
Figure 6.3.5 Reciprocating Compressor
The reciprocating or also called as piston compressor, is another type of common positive
displacement compressor. It uses the movement of a piston within a cylinder to increase the
pressure of the gas from lower pressure level to higher pressure level. It can be considered as
single acting, when the compressing is accomplished using only one side of the piston, or double
acting when it is using both sides of the piston. This machine is used when high-pressure head is
required at a low flow. Generally, the compression ratio will determine the maximum allowable
discharge-gas temperature. It can be single-stage or multistage compressor. Typical compression
ratios for the compressor are about 3 per stage in order control the discharge temperatures from
300of to 350°f. Some reciprocating compressors have as many as six stages that can provide a
total compression ratio over 300.

173. Figure 6.3.6 Reciprocating Compressor Working Principle
As shown in the figure 1.6 above the gas enters the suction manifold into the cylinder
cause by the vacuum condition that is created inside the cylinder as the piston moves downward.
When the piston reaches its bottom position it begins to move upward. So the intake valve closes
and trapping the gas fluid inside the cylinder. After that the piston continues to move upward and
compresses the gas and the pressure will increase. The high pressure in the cylinder pushes the
piston downward cause by the higher pressure that occurs in the cylinder. As the piston is
reaching near the bottom of the cylinder, the exhaust valve opens and releases high pressure gas
fluid.
Advantages
a) Simple design, easy to install
b) Lower initial cost
c) Large range of horsepower
d) Special machines can reach extremely high pressure
e) Two stages models offer the highest efficiency
Disadvantages
a) Higher maintenance cost
b) Many moving parts
c) Potential for vibration problems
d) Foundation may be required depending on size
e) Many are not designed to run at full capacity

174. 6.3.4 CompressorMaintenanceConcept
In order to maintain an air compressor system it requires well care of the equipment,
paying attention to changes and trends, and responding promptly to maintain operating reliability
and efficiency. To assure the maximum performance and service life of your compressor, a
routine maintenance schedule should be developed. Proper maintenance requires daily, weekly,
monthly, quarterly, semi-annual, and annual procedures. Monitoring operating conditions on a
daily or shift change base is good practice. It allows the operators to become familiar with a
smooth running machine which will lead to early detection of potential problems. Excellent
maintenance is the key to good reliability of a compressed air system; reduced energy costs are
an important and measurable by product. The benefits of good maintenance far outweigh the
costs and efforts involved. Good maintenance can save time, reduce operating costs, and improve
plant manufacturing efficiency and product quality
Just as with any other type of machinery, compressors are subject to operational changes
from environmental conditions, wear, or neglect. A plugged condensate drain, unusual noises,
temperature or vibration increases, discolored oil, and/or fluid leaks are some examples of
operational changes that may signal beginning of potential problems. Recognizing any changes
in operation and appropriately responding to those changes can prevent undesirable
consequences such as unscheduled shutdown and/or the expense of unanticipated repairs.
6.3.5 Maintenance Check List, Compressors Failure Symptom and Preventive Maintenance
Observation
Maintenance Check List
Daily inspection
A daily inspection takes only a short time, but it will allow the operator to develop a
definite sense of the appearance, sounds, and other operating conditions of a smoothly
performing compressor. Any changes can be investigated and be given attention before major
problems develop.
Daily operator inspection checklist
Warning: exercise care when in the vicinity of hot surfaces, pressurized air, and high
voltages.
Procedures accompanied by the alert symbol (!) Require special precautions as
indicated.
() Operating data log
Operating parameters recorded and within specifications

175. Setpoints recorded
Gearcase(high surface temperatures)
External surfaces wiped clean
No unusual noise or vibrations
No oil leaks
No water leaks
No frayed or worn electrical cables
Intercoolers and aftercooler(pressurized air, high surface temperatures)
External surfaces wiped clean
Condensate drains functioning properly
No cooling water leaks
No air leaks
Lubrication system (high voltages at heater, pump motor)
External surfaces wiped clean
Proper oil level in oil reservoir
Proper oil color
No mist from ejector system
No oil cooler water leaks
No oil leaks
No frayed or worn electrical cables
Compressor drive motor (inspect visually only—high voltages, temperatures)
External surfaces wiped clean
Properly ventilated
No erratic or noisy operation
No frayed or worn electrical cables
Inspected in accordance with manufacturer‘s recommendations
Table 6.3.1 Example of Daily Operator Inspection Checklist
Scheduled maintenance
Table 1-2 below lists suggested intervals for prescribed scheduled maintenance
procedures such as those involving filters, lubrication, and other inspections and/or adjustments.
Bear in mind, however, that these intervals may vary with operating conditions and/or actual
hours of machine operation. Some items may require attention more or less frequently as
circumstances dictate.
Scheduled maintenance procedures
() Weekly:
(or after about 150 hours of operation)
Inlet air filter elements inspected, replaced if required
Oil reservoir venting system filter elements inspected, replaced if required
Bypass valve filter checked (if supplied)

176. Every six months:
(or after about 4000 hours of operation)
Oil reservoir venting system filter element changed
Oil system filter element changed
Lubrication system oil tested and changed if required
Coolant chemically tested
Bypass valve lubricated (if required – check instructions)
Inlet guide vane assembly drive screw lubricated
Main drive coupling inspected and lubricated.
Drive motor ball bearings lubricated with recommended grease.
Oil pump motor lubricated with recommended grease
Discharge air check valve inspected
Table 6.3.2 Example of Scheduled Maintenance Checklist
Professional inspection
A substantial part of any good preventative maintenance program also involves
professional inspection and replacement of common maintenance components after an
established interval. Such in-depth inspection is particularly important when an unscheduled
and/or long-term shutdown would seriously affect production. Table 1.3 below lists the items
which require a professional service inspection whenever environmental or operational
conditions dictate. Contact a authorized service representative for those procedures and for
professional advice.
Service inspection checklist
To be performed with a manufacturer authorized representative:
() Gearcase
Impellers, inlets, and diffusers cleaned
Impellers, inlets, and diffusers inspected
Gearing visually checked
Gearing backlash clearances measured
Axial pinion float checked
Clearances between impellers and inlets checked
Intercoolers and aftercooler
Bundle tubes inspected, cleaned if required
Bundle fins inspected, cleaned if required
Cooler cavities cleaned and inspected
Lubrication system
Piping connections checked for leaks
Oil visually inspected
Oil cooler inspected
Filters
All filter elements inspected
Control panel

177. Inspected for proper operation
Control valves
Inlet guide vane inspected
Bypass valve inspected
Discharge air check valve inspected
Drive motor
Main drive coupling inspected and re-greased
Motor inspected in accordance with manufacturer‘s instructions
Table 6.3.3 Example of Service Inspection Checklist by Professional
Compressors Failure Symptom
For compressor itself there are several common failure symptoms that must be pay
attention in order to detect the problems, so that correction step can be done to prevent severe
damage to occur. In the table below show the common symptom, cause and correction step for
each symptom.
SYMPTOM CAUSE CORRECTION
High
Discharge
Temperature
Sump lubricant low. Fill lubricant.
Clogged or varnished heat
exchanger/oil cooler.
 Inspect lubricant lines for
blocks.
 Analyze lubricant.
 If varnish is present, flush with
cleaner.
Faulty thermal by-pass valve. Rebuild or replace by-pass valve.
Restriction of heat exchanger air
flow.
Remove restrictions.
Insufficient air circulation at oil
cooler.
Check location and make sure there
is no restriction of cool fresh air.
Plugged oil filter element. Replace oil filter elements
Premature
Lubricant
Breakdown
Compressor operating too hot. See corrections for high discharge
temperature.
Chemically active gases present.  Review plant/operations/make-
up air.
 Analyze oil and correct inlet air
source as needed.
Improper receiver condensate
draining.
• Periodically drain receiver
condensate.

178. • Inspect auto-drains, drain lines
and valves.
Mixing incompatible lubricants. • Drain, replace and analyze oil.
• Flush compressor with cleaner.
Frequent
Separator
Plug-Up /
Collapse
Incompatible oil in compressor.  Review and analyze oil.
 Replace with proper lubricant.
Minimum pressure valve sticking. Rebuild or replace valve.
Ruptured intake air path filter.  Inspect inlet filter and air path,
checking for voids.
 Replace and repair as needed.
Decreased
Discharge
Pressure
Excessive air demand. Check plant air demand and inspect
plant for air leaks.
Service valve open. Close valve.
Leaky service line. Fix leaks.
Plugged inlet air filter. Clean or replace filter.
Inlet valve partially closed. Check inlet valve assembly and
rebuild as needed.
Failure To
Start
Safety shut-down tripped. Re-set compressor safety.
Disconnected main switch. Check switch and verify that power
is ON.
Power failure. Check power supply.
High Power
Consumption
Plugged air/oil separator Change separator element.
Wrong air pressure setting. Adjust setting.
Obstructed after cooler. Clean after cooler.
Plugged inlet air filter. Inspect and replace as needed.
Lubricant viscosity issues. Test and replace oil as needed.
Excessive
Lubricant
Consumption
Overfilled lubricant sump. Drain receiver to proper level
Broken lubricant line .Replace lubricant line.
High compressor discharge
temperature.
• Inspect and clean coolers.
• Inspect temperature control valve.
• Improperly positioned lubricant
return scavenges line.
• Plugged scavenge line.
• Check scavenges line connections.
• Make sure that scavenge line is
cut at 45° angle, reaches the bottom
of the separator and isn‘t blocked.
Table 6.3.4 Common Failure System, Cause and Correction Step
.
Preventive Maintenance Observation
Preventive maintenance is very important in order to maintain the compressor in their
best condition. Listed below is the general preventive maintenance that can be done in order to
maintain the compressor to work in their best condition.

179. 1. Foundation
Annual. Examine concrete for cracks and spalling.
2. Frame
Annual. Examine metal for corrosion and cracks. Clean and paint if required.
3. Compressor Drive
Weekly. Check v-belts for slippage, chains for looseness, and shaft couplings for excessive run
out or vibration. Dress or tighten v-belts if required. Tighten coupling bolts and lubricate
coupling if required.
Annual. Check v-belts for signs of wear or aging and replace as needed. Check shaft run out of
direct coupled machines with dial indicator and check shaft alignment if run out is excessive.
4. Cooling System
Weekly. Check flow of water or coolant through compressor and after cooler.
Check for accumulation of dirt and lint on cooling fins of air-cooled compressors and radiators
or water-cooled compressors.
Annual. Check for corrosion and scale buildup and clean or flush as required.
Thoroughly clean cooling fins of air-cooled compressors and radiators of
water-cooled compressors.
5. Air Intake
Weekly. Check condition of filter and intake for obstructions. Replace filter as required.
6. Piping and Valves
Annual. Check piping for corrosion. Clean and repaint or replace piping as required. Repack and
reseat valves as required.
7. Aftercoolers
Not Scheduled. Check for leaks and for adequate water flow. Disassemble and check for internal
corrosion and scale buildup. Clean as required.
8. Separators
Not Scheduled. Check for leaks. Disassemble and check for corrosion and scale buildup. Clean
as required.
9. Traps
Weekly. Operate manual drains.
Annual. Check automatic traps for leaks and proper operation. Clean strainer and check for
corrosion or scale buildup.
10. Dryers
Annual. Replace dryer elements as required on deliquescent dryers. Check operation of
refrigerated and desiccant types.

180. 11. Pressure Regulating Valves
Annual. Check operation and verify that regulating valves are providing correct pressure
downstream from valve.
12. Pressure Relief Valves
Annual. Verify operation and setting. Check for signs of leaking, rust or corrosion, deposits, or
mineral buildup. Perform operational test of relief valve either in service or remove and perform
test on test stand. If a valve is found to be not functioning properly, the system immediately
should be taken out of service until the valve can be repaired or a new valve can be installed. The
relief valve setting should not be changed by plant personnel. The setting of a pressure relief
valve can only be certified by an accredited repair facility.
13. Receiver Tanks and Other Pressure Vessels
Weekly. On air receiver tanks, open the receiver drain valve and blow down until water is
removed from tank. Check for leaks on all pressure vessels. Annual. Make thorough inspection
of exterior of the tank, paying close attention to joints, seams, and fittings. The inspection should
be performed by a qualified inspector.
14. Gauges
Weekly. Check operation of gauge. Look for loose or stuck pointer. If there is any doubt about
the accuracy of gauge, remove and check calibration or replace with new gauge. Biannual.
Remove gauge and calibrate. Make any necessary repairs or replace with new gauge if gauge is
not repairable.
15. Pressure and Temperature Switches
Monthly. See that pressure switches cut in and out at proper pressures. Check setting of
temperature switches. Annual. Check switch calibration and set points.
16. Unloader
Monthly. Check that compressor is not being loaded until operating speed is reached in starting
and that it unloads at the proper pressure. Annual. Inspect valves and air lines for leaks and
valves for proper seating. Lap valves if required. Examine solenoid for deteriorated insulation or
loose connections.
17. Bearings
Weekly. Check antifriction bearing for excessive vibration or noise and schedule replacement as
required. Check for adequate lubrication. Not Scheduled. Disassemble compressor and inspect
condition of all bushings and babbitt-lined bearings. Repair or replace as required.

181. REFERENCE
1. R. Keith Mobley (2008). ―Maintenance Engineering Handbook 7th
.Ed.”McGraw-Hill,
USA. ISBN 978-0-07-154646-1
2. R. Keith Mobley (2004). “Maintenance Fundamentals.” Elsevier Butterworth-
Heinemann, Oxford, U.K. ISBN 0-07-026005-2
3. Hanlon P.C., ed. (2001). ―Compressor Handbook” McGraw Hill, Two Penn Plaza, New
York. ISBN 0-07-026005-2
4. Ling. A. L. and ViskaMulyandasari (2011) .“Compressor Selection and Sizing
(Engineering Design Guidelines)” KLM Technology Group, Johor Bharu.
5. Roger Cline, John Germann and Bill McStraw(2009). ―Maintenance Scheduling for
Mechanical Equipment” Facilities Instructions, Standards and Techniques, Volume 4-1A
– Revised 2009, U.S. Department of the Interior, Bureau of Reclamation, Denver,
Colorado.
6. “Air Compressor Maintenance.” Industrial Power Air, Muskego, WI, USA.
7. Glenn K. Moore. (2009) ―Field Service Notes (Why Compressors Fail)”, Danfoss Ltd.
Denmark.
8. R. Keith Mobley (2008). ―Maintenance Engineering Handbook 7th
.Ed.”McGraw-Hill,
USA. ISBN 978-0-07-154646-1
9. R. Keith Mobley (2004). “Maintenance Fundamentals.” Elsevier Butterworth-
Heinemann, Oxford, U.K. ISBN 0-07-026005-2

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