Plant maintenance

1. 8.LUBRICATION

2. CONTENT
1. PURPOSES OF LUBRICATION
2. PRINCIPLES OF LUBRICATION
3. PROPERTIES OF LUBRICANTS
4. CLASSIFICATION OF LUBRICANTS
5. FACTORS TO CONSIDER WHEN SELECTING
LUBRICATION SYSTEMS
6. LUBRICATION SYSTEMS
7. SAFETY REQUIREMENTS

3. Meaning Of Lubrication

 Friction – is created when there
is relative motion between two
surfaces Resistance to motion is
defined as friction .
 Lubrication is use of a material between
surfaces to reduce friction .
 Any material used is called a lubricant.

4. Machines Need Lubrication

Bearings
Gears
Cylinders and their
piston
Flexible Coupling
Chains
Wire ropes

5. Lubricant
Lubricate
Cooling
Cleaning
Protection
Sealing
Transmit
Power
What is the function
of a Lubricant ?


6. Function (1) : Lubricate

Reduce Friction and Wear
 The effects of friction
• Metal to metal contact
• Leads to wear and tear
• Generates heat
• Results in power loss
 Lubricant reduces friction by
forming a film
• Reduces ill effect of friction

7. Function (2) : Cooling

Heat Transfer
 When fuel is burnt in an engine
• 33% is useful power
• 33% removed by cooling water
• 33% by lube oil and radiation
 Lube oil removes heat from
all areas and brings it to
engine sump
 Improper cooling can lead to
over heating , lead to wear ,
distortion and failure.

8. Function (3) : Cleaning

 Clean carbon and Varnish deposits
 Flushes the entire system removing
• Soot ) ‫ناخدال‬
‫د‬
‫ا‬
‫و‬
‫س‬ (
• Acids
• Wear products
• Moisture ) ‫ةب‬
‫و‬
‫ط‬
‫رال‬ (
 Removes external contaminants dust ,
 moisture ( external )

9. Function (4) : Protection

 Protection against acids and moisture
 Very important to increase life of
component and equipment

10. Function (5) : sealing

 Oil film
• Between piston ring and linear
• Helps in creating a gas tight seal

11. Function (6) : Transmit Power

Function (5) : Noise Reduction

12. Principles of lubrication

 Four main principles :
• Hydrodynamic Lubrication
• Elastohydrodynamic
lubrication
• Boundary Lubrication
• Hydrostatic Lubrication

13. types
1. Hydrodynamic or (Thick Film Lubrication)
• it exists when the moving surfaces are separated by the pressure of a
continuous unbroken film or layer of lubrication.
• In this type , the load is taken completely by the oil film.
• It depends on the relative speed between the surfaces, oil viscosity, load, and
clearance between the moving or sliding surfaces.

16. L
ubricationandits
types
Application of hydrodynamic lubrication :
Delicate instruments.
Light machines like watches, clocks, guns, sewing machines.
Scientific instruments .
Large plain bearings like pedestal bearings, main bearing of diesel
engine .

17. L
ubricationandits
types
2 . Hydrostatic lubrication
• It is essentially a form of hydrodynamic lubrication but the film
instead of being self-generated, the separating pressure is
supplied by an external oil pump .
• Hydrostatic lubrication depends on the inlet pressure of oil and
clearance between the surfaces .

18. L
ubricationandits
types

20. L
ubricationandits
types
Application of hydrostatic lubrication :
This type of lubrication is mainly used in the following areas :
• Two stroke engines .
• Bigger machines .

21. L
ubricationandits
types
3. Elastohydrodynamic lubrication
• Is developed in heavily loaded rolling contacts .
• The contacting surface is elastically deformed,distributing the load
over a greater area .
• High pressure results in increasing viscosity of lubricant , which
improves load capacity .

23. Examples of machinery applications that operate under EHL are:
• rolling element bearings, gear teeth and cam contacts (rolling)
where high rolling contact loads occur.
L
ubricationandits
types

24. L
ubricationandits
types
4. Boundary or thin film lubrication
• Lubrication film is insufficient to separate the contacting surfaces.
• the oil film thickness is so small .
• metal to metal contact occurs between the moving surfaces .

25. L
ubricationandits
types
• Unlubricated vs boundary lub vs hydrodynamic lub

26. L
ubricationandits
types
This type of lubrication is used in the following areas :
1. A shaft starts moving from rest.
2. The speed is very low.
3. The load is very high.
4. Viscosity of the lubricant is too low.

27. L
ubricationanditstypes
5. Mixed lubrication
. is the transition between Hydrodynamic and Boundary lubrication.
. Two surfaces are partly separated, partly in contact .

28. L
ubricationandits
types

29. L
ubricationandits
types
6. Extreme pressure lubrication
. This lubrication is for very high press ,temperature, speed sliding
surfaces .
. Extreme pressure additives are used along with the lubricants .
. They are activated by reacting with the metal surface when the
temperatures are elevated due to the extreme pressure and friction .
. Then form solid surface films of (S,CL and P) , acts as a barrier to
reduce friction, wear, eliminate the possibility of welding .

31. Selection Of Lubricant

 Temperature of operation
 Speed
 Load
 Oil change interval
 Operating conditions and possible
contaminants
 Method of lubricant application
 Size , type and material of elements to be
lubricated

32. Types of Lubricant

 Gaseous lubricants
 Liquid lubricants
 Semi - solid lubricants
 Solid lubricants

33. 
Classification of Lubricant
 Solid Lubricants :
Polymer , metal – solid, carbon
and graphite , and ceramic and
cermet.

34. Types of Lubricant

Semi-Solid Lubricant ( Grease )
 Advantages Of Greases :
• Good for inclined/vertical shafts.
• Water resistant & reduce oil vapor problems.
• Reduce noise and vibration
Disadvantages of Greases :
• Because of semi-solid nature of greases, it
does not perform the cooling , so poor
dissipation of heat.
• No filtration .. So contaminants / wear-debris
cannot be separated.

35. 
Types of Lubricant
 Liquid lubricants , which include:
• Vegetable oil and animal oil
• Mineral oil from petroleum
• Blended oil , doped oil , or compound oil
Liquid Lubricants :

36. 
Types of Lubricant
 Gas Lubrication :
ADVANTAGES :
• Temperature range (-2000C) to (20000C). No
vaporization , cavitation , solidification ,
decomposition.
Very low viscosity (1000 times less viscous than
even the thinnest mineral oil ) , therefore ultra
low friction . Possible high speed.
Cleanliness.
No seal requirement for lubrication.

37. Types of Lubricant

DISADVANTAGES :
• Very low load capacity. Low damping.
Ultra low film thickness.
Smooth surfaces & very low clearance
(to maximize load capacity & minimize
flow rate) needs a specialist designers &
manufacturer (close tolerance).
Less forgiving of errors in estimating
loads or of deviations from
specifications during manufacture and
installation.

38. Types of Lubricant

 Selection of Lubricant Type :
Load and speed are two major
factors which affect selection of
lubricants environment and
sealing requirements are
additional factors which affect
lubricant selection. Apparent area,
material conductivity and friction
coefficient decide the operating
temperature.

39. Application

Industrial
• Hydraulic oils
• Air compressor oils
• Food Grade lubricants
• Gas Compressor oils
• Gear oils
• Bearing and circulating system oils
• Refrigerator compressor oils
• Steam and gas turbine oils

40. Properties of Lubricants

 Kinematic viscosity
 Viscosity index
 Pour point
 Flash point
 Total Base Number (TBN)

41. Kinematic viscosity

 Internal resistance to flow
 Selection of viscosity depends of :
• Speed
• Load
• Temperature

42. Kinematic viscosity

• Speed :
The faster a shaft rotates in a bearing the
thinker developing oil wedge will be become .
Therefore , for high speed application we need
a light-bodied oil ( low viscosity oil ) and ,
conversely . for low speed applications an oil
with heavy body ( high viscosity ) is Required

43. Kinematic viscosity

• Load :
A lightly-loaded application will
operate with a lighter-bodied oil
(low viscosity oil) than a heavily
loaded one, as a lesser load-carrying
lubricating film is required.

44. Kinematic viscosity

• Temperature :
Viscosity is dramatically influenced by
temperature, . shown in the following
diagram illustrating . experiment conducted
on the same oil but at varying temperatures.
At low temperature , oil does not flow as
free, at high temperature. It is, therefore ,
very important to indicate the temperature at
which the viscosity was determined wh.
reporting a viscosity.

45. Kinematic viscosity

Low Viscosity oils used :
• High speeds
• Low pressure
• Low temperature
High Viscosity oils used :
• Low speeds
• High pressure
• High temperature

46. Viscosity index

Measure of fluids change
of viscosity with
temperature.
Higher the VI lower will
be the change of viscosity
with temperature
• high number , less change
• low number , more change

47. Pour Point

• Lowest temperature at which the
fluid will flow
• Indicates lowest operating
temperature
• Measured in °C or °F

48. Flash Point

• Lowest temperature at which the
vapor above the liquid will ignite
under flame.
• Indicated safe maximum
temperature of operation.
• Indicator of volatility.
• Test method - COC and PMCC
• Measured in °C

49. Total Base Number ( TBN )

• Measured the acid neutralizing
reserve in oil.
• Important for deciding discard of oil
• Decreases due to
• Oxidation of oil
• Water contamination
• Fuel contamination
• Measured in Mg KOH/g of oil

50. Lubrication Handling
& Storage
Introduction :-
Proper handling and storage of lubricants can be of great
benefit to the customer. Contaminated lubricants can be
a major cause of equipment failure. The resulting
downtime for repairs is very costly. A small amount of
effort spent in organizing oil and grease stocks and
making sure that they are handled and stored properly
will save time and money by increasing production and
reducing maintenance costs.
Content :-
1- Receiving New Lubricants.
2- Storage.

51. Receiving New Lubricants
Procedures :-
1 Correct Unloading.
2 Moving Containers/Drums to Storage Area.
Techniques :-
1 Using forklift trucks.
2 Manually operated.

52. 1- Using Forklift Trucks :-
If containers are
palletized, a forklift
should be used to
unload the
lubricants from the
shipping vehicle.

53. 1- Using Forklift Trucks :-
For drums not
shipped on
pallets, special
drum handling
attachments for
forklifts should
be used to
remove the
drums from the

54. 2- Manually Operated :-

55. Storage
Target :-
“ Reducing Contaminations ”

56. Contamination Causes :-
1 Damaged Containers or drums.
2 Poor Storage Practices.
3 Dirty handling & dispensing equipment.
4 Moisture seeping into tanks or containers.

57. Indoors Storage
• The recommended
method of storing
lubricants is indoors in
a designated oil area or
an oil house.
• An oil house or indoor
storage facility should
have racks and
shelving that allow for
adequate protection of
drums as well as ease
of placement and
removal.

58. Indoors Storage
• The efficient use of an oil storage area or oil house will
also allow better stock rotation. Access to the older
stocks should always be open so that the older
lubricants will be used first. The First In, First Out (FIFO)
method of inventory control will eliminate the risk of
deterioration caused by excessive storage period.
• Even when stored indoors, contamination can occur
when transferring the lubricants to the various pieces of
dispensing equipment or when adding to the machine
to be lubricated.

59. Indoors Storage
Precautions :-
1. Pumps, funnels, oil cans, hoses, grease guns and
other dispensing equipment should be kept clean and
stored in a closed vented cabinet or covered when not
in use.
2. When adding oil to equipment, do so in a manner
that will not add dirt to the system.
3. Always clean the top of the reservoir and around the
filler cap before removing the cap.
4. It is also good practice to add the oil through a cloth
or metal screen to prevent the accidental entry of dirt
into the reservoir.

60. Outdoors Storage
Disadvantages:-
1. When drums are stored outside, the weather and
elements can fade important drum markings and
labels. If the drums have weathered severely enough
that the product inside cannot be identified, this can
lead to using the incorrect lubricant in a particular
piece of equipment and possibly damaging that
equipment.
2. The effects of changing temperature on lubricant
containers can be seen in several ways.

61. Outdoors Storage
Precautions :-
1. drums should always be covered
with a shelter or at least a
plastic drop cloth to protect the
drums from rain and other
sources of water.
2. The preferred position for
outdoor storage is with the
drums on their sides and bungs
approximately horizontal.
3. Drums should be stored on
racks or at least on blocks
several inches above the
ground, to prevent additional
moisture damage.

62. The effects of changing
temperature on lubricant Drums
Low-Temperature Degradation of Lubricants
• Most good quality synthetic and conventional mineral
oils are not affected by storage temperatures below
120°F (49°C). However, storing lubricants near furnaces,
steam lines or direct sunlight in high temperature
climates for a prolonged time period may cause
additives and base oils to oxidize prematurely.
• Lubricants that are potentially contaminated with
volatile products, including diesel fuel, kerosene, or any
other solvent, must never be stored in high
temperatures. The presence of solvents can be
identified by a test called the flash point test.

63. The effects of changing temperature on
lubricant Drums
Low-Temperature Degradation of Lubricants
• The major difficulty from cold storage
temperature arises from the high viscosity of
these fluids and the difficulty of pumping them
to operating equipment and transport vessels.
• Products that contain significant amounts of
water, like water-glycols and oil-water
emulsions, should not be exposed to
temperatures below 40°F (4°C).

64. The effects of changing temperature
on lubricant Drums(Outdoors
Storage)
• Alternating periods of
extreme hot and cold can
cause the metal of a drum to
expand and contract. This
expansion and contraction
can cause the seams of a
drum to weaken. As a result,
the drums may begin to leak
and lubricant may be lost.
• If water is allowed to
accumulate on the top of a
drum, temperature changes -
alternating heating and
cooling - causes a vacuum,
which can cause moist air to
be sucked into the drum
vapor space.

66. ⦁ Lubrication
⦁ powertransmission
⦁ surface protection
⦁ heat transfer
⦁ surface cleansing

67. ⦁ Reduction of friction
⦁ Corrosion prevention
⦁ Heat removal
⦁ rust prevention

68. ⦁ Transmission parts.
⦁ Bearings.
⦁ Cams.
⦁ Journals.
⦁ Seal faces.
⦁ Any situation involving metal to metal contact.

69. ⦁ SuctionFilter
⦁ PressureFilter
⦁ ReturnFilter
⦁ PilotLinePressureFilter
⦁ DuplexHighPressureFilter
⦁ DuplexLowPressure,HighFlowFilter
⦁ Off-LineFilter(Dedicated)
⦁ Off-LineFilter(Mobile)

72. ⦁ Filter carts have become an essential tool in many hydraulic and
lubrication systems.
⦁ Because new oil in drums or totes typically does not meet stringent
OEM cleanliness specifications, it should be filtered prior to use in
hydraulic or lubrication applications.

74. ⦁ particulate Removal
⦁ WaterRemoval
⦁ AcidRemoval

77. Signs of Lubricant Starvation

78. "What is the first indication of
lubricant starvation?"
• Heat is the direct consequence of lubricant
starvation. Once any mechanical system
becomes depleted of lubricant, and the
lubricating film keeping gears, bearings or
slides apart is no longer present to support or
protect the surfaces, surface-to-surface
contact will occur. When two surfaces slide or
rub together, friction is produced, and from
friction comes heat.

79. Before frictional heat is generated, the only way to detect lubricant
starvation would be through vibration analysis. Vibration analysis
can pick up subtle vibration changes in the machinery and may be
able to identify lubricant starvation before the extreme heat from
friction is discovered.
The effect of friction on the two surfaces rubbing together without
lubrication will cause them to heat up quickly. The amount of heat
generated will be in direct correlation to how fast the two surfaces
are sliding or rotating. For example, gears rotating at only 60 rpm
will take much longer to heat up than those rotating at 1,800 rpm.
Without proper lubrication, gears rotating at faster speeds not only
will heat up quickly but can also lead to failure of the machine.

80. In the image below, notice the difference between a good oil
supply (full lubricant film), an impaired oil supply (boundary
contact), and dry friction and wear (caused by lubricant
starvation). Welding and galling occur when the two surfaces
become so hot that they weld together and then tear apart,
resulting in large amounts of debris. This is not something you
want happening inside your machine.

81. Other signs that your machine is suffering from lubricant starvation
include smoke, an unusual smell and the machine becoming hot to the
touch. Smoke is caused by the heating of what is left of the lubricant.
This is usually the case when you see some poor soul stranded by the
side of the road with smoke pouring out from under the hood of his car.
Before a machine even begins to smoke, you can often smell the oil
starting to heat up. This provides a good way to detect lubricant
starvation.
Another excellent method is through touch. Your hands are very
sensitive heat detectors and can identify subtle changes in
temperature.
However, the most effective way to combat lubricant starvation without
expensive diagnostic equipment is to check your machinery on a
regular basis. Ensure your PMs are appropriate for each machine and
take into account the changing conditions around the equipment, such
as temperature, moisture and workload

82. Determining an Oil's Energy Efficiency

83. "We have two different oils and need to determine which one is more
energy efficient. What data should we collect? What parameters can
help establish energy efficiency?"
Energy efficiency must be measured in terms of the reduction of
energy consumption. More specifically, it is related to how much
energy the machine consumes in order to operate. This principle
applies to machines that convert one type of energy like chemical or
electric to a mechanical one, such as electric motors and combustion
engines. It is also applicable to machines that transmit mechanical
energy, like gearboxes. In some cases, it may be evaluated in a
powertrain such as a combination of a combustion engine and a
transmission.

84. The energy saved is measured in terms of what is utilized to
move or operate the machine. For example, for a combustion
engine, the reduction in fuel consumption would be measured.
For an electric motor and/or gearbox, the reduction of electric
energy (voltage, current and power factor) would be measured.
The energy savings can also be measured indirectly by simply
verifying a reduction in the operating temperature. This can be a
practical method for electric motors, gearboxes and pillow block
bearings. Although it likely will not reveal the amount of energy
saved, there will be a clear indication of the reduced energy
consumption

85. It is important to note that certain conditions must be kept
consistent for the sake of comparison. These conditions would
include using a similar amount of lubricant (the same oil level or
regreasing amount), measuring the equipment in similar operating
conditions (load and speed), and maintaining similar ambient or
room temperatures. Preferably, the same instruments and methods
should also be used to measure the energy consumption for both
lubricants. Otherwise, similar or comparable instruments should be
utilized. Finally, be sure to take several readings to minimize the
impact of inevitable variations.

86. Why should we prevent leakage
???
🠶It has been estimated that more than 100
million gallons of lubricants could be saved
every year if external leakage from pumping
systems, hydraulic machines, gear cases and
sumps was eliminated .
🠶Studies have indicated that every year the
average plant uses four times more oil than
its machines actually hold, and this is not
accounted for by frequent oil changes.

87. Why should we prevent
leakage ???
🠶 Approximately 70 to 80 percent of hydraulic oil
leaves the system due to leakage, spills, line
and hose breakage and fitting failures
🠶 The lack of attention to a few basic details costs
millions of dollars annually in make-up oil,
cleanup, disposal of external fluid waste,
unnecessary maintenance downtime, safety and
environmental damage.

88. What are the causes of
leakage ???
🠶seals and packings .
🠶pipe joints and gaskets
🠶damaged ruptured and corroded lines
and vessels
🠶wrong selection improper application
🠶 poor installation and inadequate
maintenance practices that are applied to
sealing systems.

89. What are the causes of
leakage ???
🠶Overfilling
🠶 pressurization from plugged vents
🠶 worn seals
🠶over-torqued gaskets

90. 🠶The major reasons for initial seal
failure and fluid leakage are cost-
cutting by machine design engineers
🠶 incomplete commissioning and plant
start-up procedures
🠶inadequate equipment condition
monitoring and maintenance practices.

91. Once a seal has failed and fluid leakage
results :
🠶 the problem is perpetuated by purchasing
low-quality or incorrect seals
🠶 careless installation practices used during
replacement procedures.
🠶 The subsequent leaks, while possibly not
considered excessive, can go on and on.
Soon plant operating and maintenance
personnel accept the leakage as normal.

92. How to discover leakage !!!!!!!
????
🠶Leak detection can be by :
🠶 visual inspection .
🠶 possibly aided by the use of dyes
.
🠶through make-up oil records.

93. How to control leakage !!!!!
🠶Engineers should pay more
attention for lubrication when
designing machines .
🠶Use modern systems .
🠶Now that how leakage are danger
and cost phenomena .

94. Safety tips for
handling
Lubricants :

95. In case of contact with the skin :
🠶Respect strict personal and industrial
hygiene rules.
🠶To avoid contact with the body:
- use oil-proof gloves, wear clothes with an
efficient protection, do not wear oil
contaminated clothes, solvents, such as
petroleum.
🠶petrol must not be used to remove oil
from the skin, use a protecting cream.

96. In case of contact with
the eyes :
🠶Wearing safety goggles is highly
recommended when oil is likely to
splash in the eyes.
🠶 In case oil accidentally splash into
your eyes, thoroughly rinse them with
water for at least 15 minutes and
contact a physician if irritation persists.

97. In case of inhalation :
🠶Avoid inhaling oil mists and fumes.
🠶Premises should be properly
ventilated.
🠶The acceptable limit for an oil mist is 5
mg/m3.