Scope of this technical presentation is to identify the prerequisites of an appropriate industrial valve maintenance methodological approach

1. www.coemi.it
An appropriate methodology to achieve
a clear vision of the valves and properly
perform their maintenance
Ing. Mario Mirenda 2021

2. COEMI specialized on Valve Maintenance in
more than 30 years of activities, performing
maintenance services in all type of industrial
plants. Moreover, to increase the quality of the
service provided, implemented an Engineering
team to technically support the valves
department.
Valve Maintenance Department
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3. Satisfy customer productive requirements providing top quality services for any type of
valve and associated instrumentation, in conformity with main international safety and
environmental standards.
Valve Maintenance Department – Mission
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4. Technicians continuous training by specific updating courses and investing on
equipments to keep a valve workshop fully equipped with last generation machinery,
device and tools, which reflects company policy to continuously improve in terms of
quality standards and customer satisfaction.
Valve Maintenance Department – Core Values

5. Industrial plants are perfect and complex
machines, engineered and assembled with
specific technology and equipments to
maximize productivity and efficiency.
Valves are crucial instruments, which
control and operate any plant process and
definitely they are essential components of
a reliable production systems.
Any given valve performs a specific task
also to grant plant safety and environment
protection.
Valves are the heart of industrial plants
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6. Valves general statistical data
 Right, after compressors, valves are the main cause of plants
shutdown.
 About 60% of fugitive emission and leakages are originated
by valves malfunctioning.
 Valves are among the main causes of production fault,
environment pollution, safety issue and in the most severe
cases, major accidents or disasters.
 More than 25% of purchased spare parts available in stock
are obsolete. Often necessary spare parts are not available;
 Pre-shutdown planning time and human resources increase
of more than 30% when it is not organized with a
methodological approach.
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7. In any complex industrial plant there are installed thousand of valves of different
manufacturer, typology, size and actuation system.
Too many valves to handle!
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8. Most of them are out of production, some are of new
construction and technologically advanced.
A recurrent problem when overhauling a great number of
valves is the shortage of information. Typically this
problem is faced during plants turn-around.
To properly organize their maintenance it is required an
extensive experience in several specialization.
Collect valves technical documentation and perform
accurate on-site survey are fundamental to organize a
proper valve maintenance plan and to allow a clear
vision of each valve status.
Too many valves to handle!

9. Scope of this technical presentation is to identify the
prerequisites of an appropriate methodological
approach. They are summarized as follow:
 Collect Valve data;
 Analysis of collected data;
 Perform overhaul matching specialized technicians,
with appropriate machinery and equipment.
Support and cooperation with customer engineering
department is fundamental to get best results!
PERFORM
ANALIZE
COLLECT
Appropriate methodology to perform valve maintenance
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10. OFFICE ACTIVITIES
 Plant valve list
 Technical data-sheet
 Technical drawing of valves and actuators
 Manufacturer’s manuals and associated
maintenance recommendation
 Manufacturer’s testing certificate
 P&ID drawings
 Historical maintenance reports
 Remarks form process engineering dpt.
Collect valve data

11.  Installation
 Elevation
 Accessibility
 Insulation
 Instrumentation installed, such as positioning
system, field transducers, converters etc.
 Critical visual inspection to detect leakages,
corrosion, cracks, etc)
 Functionality inspection
 Conformity with technical documents
 Take photos of relevant evidence
 Other
Collect valve data
ON SITE SURVEY
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12. The analysis of the collected data gives a
clear vision of:
 Selection of critical spare parts, both for
valves and actuators, as per manufacturer
indication.
 Evaluation of the proper testing procedure
and standards (API, ANSI, other) to
perform for each valve overhauled.
 Verify valve assembling typology, (fully
welded, fully flanged or composed) to
decide the proper maintenance strategy.
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Critical analysis of collected data

13. The analysis of previous maintenance reports
associated to collected data provides evidence of
process severity which may cause components
quick deterioration. This analysis is also
fundamental to:
 Arrange an appropriate maintenance schedule in
order to prevent valve sudden failures.
 Evaluate and propose suitable construction
materials for severe service.
 Evaluate and propose application of anticorrosion
protective coating.
 Evaluate the valve replacement with a more
appropriate one.
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Critical analysis of collected data

14. Site survey and manufacturer manual
provides additional info about the actuation
systems and the associated instrumentation
to:
 Define in advance the required expertise,
e.g. mechanics, instrumental or electrical.
 Arrange the proper maintenance activities,
calibration and necessary testing
equipment.
 Acquire information related to appropriate
parameters setting of electrical actuators
since they depend on the specific
application.
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Critical analysis of collected data

15. A complete data analysis allows to identify the
valves typology (PSV, Emergency shut down
valves, valves conveying aggressive or
dangerous fluids) which, in case of
malfunctioning, may cause safety and
environmental issue or major accidents.
In fact for this valves typology it is necessary
to:
 Implement a proper inspection and
maintenance plan.
 Identify the deteriorated or damaged valves in
order to plan, eventually, their replacement.
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Critical analysis of collected data

16. Acquired data examination of each single valve
provides information about maintenance and
inspection strategy (preventive, predictive,…):
 If site survey gives evidence of valve body
corrosion, then a routine corrosion inspection is
highly recommended.
 In case of issues related to the bonnet and stem
packing, then perform routine external leak
monitoring or stem cleaning and greasing. A
regular valve repacking is essential.
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Critical analysis of collected data

17.  Evidence of a quick corrosion of internal
components (trim) requires routine monitoring of
internal leak to have reliable information about the
status of erosion vs. time.
 Issues related to the actuation system requires
field routine actuator inspections or predictive
diagnostic maintenance. E.g. valves with “smart”
positioner showing evidence of an increasing
friction trend can indicate potential problems.
Today are available diagnostic systems of “third
generation” able to provide real time information
on valve and actuator performance
Moreover:
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Critical analysis of collected data

18. Acquired data examination of each single valve
allows to plan an appropriate maintenance strategy
to optimize and speed up activities planned or
upon fault.
For example:
 Welded valves: perform on site activities to avoid
piping cuts and welding.
 Welded PSV with direct load spring : perform on
line calibration.
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Critical analysis of collected data

19. Data examination allows to choose the proper
maintenance strategy: Repair or replace?
Almost all valves can be reconditioned, but it is not
always economically convenient. A critical analysis
provides input about the proper strategy to adopt for
each single valve:
 for some valve typology, such as gate valve of
small size, it may be convenient and much faster
to replace instead to repair. Things are different
for control valves because their design is
specifically engineered for a specific type of
process.
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Critical analysis of collected data

20. In addition, site survey and accurate diagnosis of critical valves
allows sometimes to take immediate action in order to extend
valve’s life.
For example:
 Valves processing liquids having a wrong “stroke” calibration may
cause the trim quick corrosion. In this case an immediate
improvement of valve performance is often obtained just
performing the positioner recalibrations.
 Electro-mechanic actuator inspection gives information about oil
leaks, meteoric water or dust intrusion from damaged o-rings or
gaskets that may cause sudden faults. It suggests an immediate seal
kit replacement.
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Critical analysis of collected data

21. Site survey and accurate diagnosis of critical valves allows to take
immediate action in order to extend valve’s life and risk.
For example:
 Pneumatic actuators functionality inspection allow to detect friction
or o bad stem travels. It may suggests an immediate complete
overhaul.
 Friction detected while opening or closing a valve can be eliminated
by greasing the internal components. In fact, some valve typology
such as plug or ball valves, require a regular greasing to guarantee
the sealing and lubrication.
 Often just tightening the packing gland can eliminate a stem
leakage.
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Critical analysis of collected data

22.  Quick availability of technical info
 Critical valves summary
 Alerts on intervention schedule
 Prompt maintenance and inspection strategy
 Complete spare parts and accessories list
 Alerts of the most critical spare parts
 Remarks form process engineering dpt
 Expertise required
 Archive of maintenance reports
Critical analysis of collected data
Inputting collected data and information in a dedicated database provides a fast and
reliable tool for:
In addition, the information and data collected facilitate the Asset Integrity Management
(AIM) for Reliability Centered Maintenance (RCM) or for a Risk Based Inspection
(RBI) program.
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23. Scope of a proper maintenance is to provide the customer with valves operating to the
same characteristic and performance of the original one. Best maintenance is based on
specific technical procedures, technician full expertise and appropriate machinery and
equipment. In particular it is required:
 Technicians with mechanical, electrical and
instrumental extensive expertise, both on site and at
workshop.
 Technicians properly trained to work as per
applicable safety procedure;
 Technicians trained for valve and actuator
maintenance, possibly certified by manufacturer;
 Technicians specialized on valves inspection (leaks
monitoring, corrosion, NDT, instrumentation
diagnosis, etc.);
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Perform best maintenance

24.  Certified welders to repair damaged
components as per appropriate WPQR
(Welding Procedure Qualification
Record);
 Specific quality control plan for each
type of valve following manufacturer
indication;
 Procedures, equipment and know how
for body/bonnet controlled bolting;
Best maintenance is based on specific technical procedures, technician full expertise and
appropriate machinery and equipment. In particular it is required:
Perform best maintenance

25.  Appropriate procedures to perform surfaces
preparation, painting and related control.
 Technicians specialized on machining
techniques which support overhauling
activities, in workshop and on-site.
 Appropriate lapping techniques to restore the
correct dimensional tolerances of internal
components
 Appropriate testing procedures and certified
machinery and equipment for final test report
release to guarantee valves conformity with
original manufacturer.
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Best maintenance is based on specific technical procedures, technician full expertise and
appropriate machinery and equipment. In particular it is required:
Perform best maintenance

26. Perform best maintenance
An example of non-application of a methodological approach show the severe
degradation due to sea water corrosion of a butterfly ND 72” valve, as revealed into the
pictures. A timely critical analysis would have given indication on a proper maintenance
time schedule, suggesting also the application of a protective coating to perform a better
resistance against corrosion.
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27. Focus on the plant productivity
Thanks to the application of an appropriate methodological approach and its
management, our costumers has improved their control having a clear and critical
vision of each valve. All the information collected allow to optimize precious time, the
availability of necessary spare parts and to plan better the activities to perform on the
valve.

28. THANK YOU!
Taking care of valves means
environment protection, plant safety,
reliable productivity and process
efficiency.
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Conclusion