Maintain and repair instrumentation & control devices

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Course: Instrumentation and Controls Servicing NC III
Unit of competency: Maintain and Repair Instrumentation & Control Devices

Module: At the end of the session, learners should be able to:
Learning outcomes:

1. Interpret work instructions for maintenance and repair

2. Identify tools, equipment testing devices and materials needed for
Maintenance and repair

3. Identify the PPE and OHS policies and procedures required for the
maintenance and repair job

4. Maintain instrumentation and control devices
5. Repair instrumentation and control devices
6. Inspect and test the repaired instrumentation and control devices

Duration: 40 HRS
Situating Learning: You are a Junior Instrument Technician in Petron Bataan Refinery. You
are assigned to conduct Maintenance Job for all the Instruments
installed at PRU area. The scheduled plan is to check all Level
Switches in the area. For you to complete the task you need a Work
Instruction Sheet for each Instrument. This Work Instruction covers the
scheduled maintenance of Float Level Switches in the field and the
confirmation that they are functioning in accordance with the design.

Before carrying out your job you must plan, prepare and take into
consideration the following aspects.

 Hazards

Ensure that any safety precautions required is applied prior to any field
work commencing.

Operation’s department should be aware of all work being carried out.

 References (operation manuals, datasheets, etc.)

 Materials and Equipment

 Responsibilities

Instrument Supervisor is responsible for raising the Work Permit and
that the job is performed correctly and is aware of all hazards present,
also including the recording of history details.
The Instrument Technician is responsible for the execution of the work
and for compliance with this Work Instruction
Operations department responsible for issuing and closing work permit
and verifying a safe working environment.

 Work instruction / Activity

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You will need to complete the Maintenance Checklist Report and Let it
check by your supervisor.

This is your first year on the job as junior technician and being expert in
the job could mean possible regularization or pay rise.

Assessment Criteria: ASSESSMENT CRITERIA: (LO1)

1. Communication skills to interpret work instructions are defined
and demonstrated according to the established procedures

2. Work signs, symbols and conventions are defined and explained
according to the set standards

3. Work instructions and procedures are demonstrated according
to the set standards

ASSESSMENT CRITERIA: (LO2)

1. Materials needed for maintenance and repair are identified and
prepared according to the work instructions

2. Tools and equipment types and functions needed for
maintenance and repair are identified and demonstrated
according to set standards

3. Testing devices and instruments operations needed for
maintenance and repair are explained and demonstrated
according to instruction manual

4. Personal protective equipment are used in accordance with the
Occupational Health and Safety guidelines and policies

ASSESSMENT CRITERIA(LO3)

1. Personal Protective Equipment (PPE) needed for maintenance
and repair are identified and prepared according to the work
instructions

2. Use of PPE needed for maintenance and repair are
demonstrated according to the set standards

3. Occupational and Health Safety (OHS) needed for maintenance
and repair are identified and explained according to the work
instructions

4. OHS procedures and policies needed for installation are
demonstrated according to the set standards

ASSESSMENT CRITERIA: (LO4)
1. Appropriate personal protective equipment is used.
2. Normal function of instrumentation and control devices is
checked in accordance with manufacturer’s instructions &
standard procedures.
3. Scheduled/periodic maintenance is performed in accordance
with manufacturer’s requirements.
4. Unplanned events or conditions are responded to in accordance
with established procedures

ASSESSMENT CRITERIA: (LO5)
1. Appropriate personal protective equipment is used in line with
standard procedures.
2. Normal function of instrumentation and control devices is
checked in accordance with manufacturer’s instructions.
3. Fault/s or problem/s in system or component is diagnosed in line
with the standard operating procedures.
4. Unplanned events or conditions are responded to in accordance
with established procedures

ASSESSMENT CRITERIA: (LO6)
1. Final inspections are undertaken to ensure that the testing

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conducted on the device conforms with the manufacturer’s
instruction/manual
2. Instrumentation and control devices are checked to ensure safe
operation.
3. Work site is cleaned and cleared of all debris and left in safe
condition in accordance with company procedures
4. Report is prepared and completed according to company
requirement

Learning Performance Criteria Learning Activities Learning documents
chunk (Brief description of (Documents referenced by
strategies, sequence
Sub-task 1: of lesson, evaluation) each learning activity)
1. Plan and
prepare the  Maintenance or 1.1 Plan and prepare Info sheet 1.1.1 (Planning
workplace Maintenance Job)
repair is the maintenance &
Info Sheet 1.1.2 (Types of
planned and repair job Maintenance)

prepared in line Work sheet 1.1.3 (Identifying
Planning Methods and Stages)
with job

requirements.

1.2 Identify PPE, tools Info Sheet .1.2.1
and equipment needed ( Safety Guidelines and
and list safety and Procedures-Oil and Gas)

 OHS policies precaution guidelines

and procedures needed in conducting
are followed in Maintenance and Repair
line with job Job.

requirements

Sub-Task 2:  Normal 2.1 Identify Types of Work Sheet 2.1.1 (Basic

2.Maintain I & function of Process Control System Control System, Process
C Devices
instrumentation Variables)

and control

devices is Info Sheet 2.1.2

checked in (Process Control System)

accordance

with Info Sheet 2.2.1
manufacturer’s (Control Valve Maintenance)

instructions &

standard 2.2 Identify I & C Operation Sheet 2.2.2
procedures Devices Working
Principle (Threaded and Wafer Style
Flowmeters Operation and
Maintenance

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Learning Performance Criteria Learning Activities Learning documents
chunk (Brief description of (Documents referenced by
 Scheduled/peri strategies, sequence
Sub-Task 2: odic of lesson, evaluation) each learning activity)
3.Maintain I & maintenance is
C Devices performed in 3.1 Read and Interpret Info Sheet 3.1.1 (Work
accordance work instruction for Instructions)
with maintenance job.
manufacturer’s Job Sheet 3.2.1 (Field
requirements. 3.2 Conduct Field Inspection Check of Control
Inspection check of Valve with Electro/Pneumatic
instruments and its Positioner)
normal function.

 Unplanned Operation Sheet 3.2.2 ( How
events or to Use Smart Field
conditions are Communicator)
responded to in
accordance Job Sheet 3.2.3 (Field
with Inspection Check of Smart D/P
Transmitter)
 established
procedures

Sub-task 3:  Tools, 4.1 Identify Different Info Sheet 4.1.1 (Types of
4. Repair I & C
Devices equipment and Types of Repair and Repair and Repair

Sub-task 4: testing devices Repair Techniques Techniques)
5.Test I & C needed for the
Devices
maintenance/re

pair are 4.2 Take out I & C Operation Sheet 4.2.1
obtained and
checked for devices out of operation (Disassembly/Assembly of I &

correct and C Devices-Pressure

operation and disassemble/assemble I Transmitter)
safety & C devices

 Fault/s or 4.3 Diagnose fault, Operation Sheet 4.3.1
problem/s in Repair and/or replace I (Troubleshooting Guide-
system or & C devices FieldTransmitter)

component is

diagnosed in Jobsheet 4.3.2

line with the (Troubleshooting Pressure
standard Transmitter)
operating

procedures

 Final 5.1 Conduct tests & Operation Sheet 5.1.1 (Testing

inspections are inspection of I & C of I & C Devices-
undertaken to
ensure that the Devices. Instrumentation Pressure
testing
conducted on Test)
the device
conforms with Operation Sheet 5.1.2
(Calibration of Differential

the Pressure/Pressure Transmitter
manufacturer’s Calibration)

instruction/man Job Sheet 5.1.3 (Differential

ual

Pressure/Pressure Transmitter

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Learning Performance Criteria Learning Activities Learning documents
chunk (Brief description of (Documents referenced by
strategies, sequence
of lesson, evaluation) each learning activity)

 Instrumentation Calibration)

and control

devices are

checked to 5.2 Fill-up Maintenance Info Sheet 5.2.1 (
ensure safe Checklist/Report.
operation.

 Report is
prepared and
completed
according to
company
requirements

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© 2010, Institute of Technical Education, Singapore

Information Sheet 1.1.1 : Planning Maintenance Job

Learning outcomes:
1 Plan and Prepare the Workplace
Learning Activity:
1.1 Plan the Maintenance and Repair Job

Good planning provides the basis for a systematic maintenance policy. Planning requires
foresight. A good plan is the best tool to get a good idea of the work to be carried out. All
planning is centered on the activities comprising the work to be carried out. These should be
known in the greatest possible detail. This brings us to the main problem in planning. Planning
provides better predictions as it becomes more detailed, which obviously requires more effort.
Hence, the plan forms a model of the work to be carried out. Depending on the nature of the
Project a higher or lower level of detail will be required. Effective planning includes the
following three stages:

 the planning itself;
 assessment or checking;
 Correction.
These stages are not independent but should merge into each other. This is illustrated in
figure 1.

Figure 1.1.1

Planning Methods

1. Time Planning- In this case, we make a distinction on the basis of time. We use the
common distinction between short-term and long-term plans.
2. Long Term Planning- Long-term planning includes maintenance forecasts spanning
several years, e.g. more than five years. This type of planning can be used to implement
certain policies. For example, a replacement campaign, painting, contract and supplier
management, stores and stock planning, etc. Such plans form an essential part of the
maintenance policy and provide the basis for effective maintenance. As such policy decisions

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Information Sheet 1.1.1 : Planning Maintenance Job

are often particularly important, in financial and other terms, they are generally made at a
relatively high level.
3. Short Term Planning- Short-term planning generally covers activities to be carried out
within a year. Examples include planning overhauls, capacity, minor shutdowns, modifications,
preventive maintenance, lubrication, etc. Sometimes, short-term planning involves developing
an activity, initiated by the long-term planning, in greater detail.

Stages of Maintenance

Figure 1.1.2
1. Preparation Stage- In the preparation stage we can distinguish three main activities:

 Estimating the costs
 Identifying the work to be carried out
 Work planning (scheduling).
2. Planning Stage- Once the work has been defined and prepared for we can start planning
the shutdown. We can use any of the planning methods discussed earlier, from basic
Gant planning to sophisticated network planning methods. During the planning stage we will
generally follow a top-down approach. This means that large projects are divided into smaller
units. If necessary, the level of detail can be increased to refine the planning. After that, it is
relatively easy to determine the whole of the work to be carried out, as this will be the sum of
the parts. It is important to be aware of the relationships between the various projects. The
exact subdivision process depends greatly on the nature of the project, and experience is also
most important. Once all projects have been included in the planning and all constraints and
conditions have been fulfilled, the execution of the work can start.

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Information Sheet 1.1.1 : Planning Maintenance Job

3. Execution Stage- The actual maintenance operations are undertaken during the execution
stage. It is very important that there is constant feedback from the shop floor to the planning
department. This includes information about progress, such as starting and stopping times,
repair information, problems concerning parts, tools, inspection data, etc. In this stage, the
main task of the planning office is to coordinate the activities and record relevant information.
4. Evaluation Stage- During the evaluation stage, the way in which the shutdown was carried
out is critically considered. An effective approach is to determine, together with those
responsible, where and why the original planning was not followed, and where the planning
can be improved in future. Important indicators can be provided by analyzing the hours spent
on the project, additional work, additional orders, etc. Of course, this requires that this
information is carefully recorded. This stage is often considered as an unnecessary waste of
time. However, this is quite wrong. A good evaluation forms the basis for future improvement
which can result in significant cost savings in the long term.

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Information Sheet 1.1.2 : Types of Maintenance

Learning outcomes:
1 Plan and Prepare the Workplace
Learning Activity:
1.2 Plan the Maintenance and Repair Job
Optimization of Instrumentation and Control Devices assets depends on an effective
maintenance philosophy and program. There are four types of maintenance that organizations
use to varying degrees:

Reactive/Corrective – Action is taken after an event has occurred. Wait for something to
happen to an instrument and then repair or replace it.

Corrective maintenance is probably the most commonly used approach, but it is easy to see its
limitations. When equipment fails, it often leads to downtime in production. In most cases this
is costly business. Also, if the equipment needs to be replaced, the cost of replacing it alone
can be substantial. It is also important to consider health, safety and environment (HSE) issues
related to malfunctioning equipment.
Corrective maintenance can be defined as the maintenance which is required when an item
has failed or worn out, to bring it back to working order. Corrective maintenance is carried out
on all items where the consequences of failure or wearing out are not significant and the cost
of this maintenance is not greater than preventive maintenance.

Preventive – Action is taken on a timetable based on history; that is, try to prevent something
bad from happening.

So to avoid the problems of correcting unfortunate situations that have already arisen, many
try to maintain equipment before it fails. By doing this, the goal is to avoid failure, unnecessary
production loss and HSE violation. As you cannot possibly maintain your equipment at all
times you need some way to decide when it is proper to perform maintenance. Normally this is
done by deciding some inspection/maintenance intervals, and sticking to this interval more or
less affected by what you find during these activities. The result of this is that most of the
maintenance performed is unnecessary; (unsubstantiated and no source cited) it even adds
substantial wear to the equipment. Also, you have no guarantee that the equipment will
continue to work even if you are maintaining it according to the maintenance plan.
The effectiveness of a preventive maintenance schedule depends on the RCM analysis which
it was based on, and the ground rules used for cost-effectivity.

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Information Sheet 1.1.2 : Types of Maintenance

Predictive or Condition Based Maintenance – Action is taken based on field input using
state-of-the-art, non-intrusive diagnostic test and evaluation devices or using smart
instrumentation which is typically vibration analysis, lube oil analysis, ultrasound analysis,
Thermography, etc.

Proactive Maintenance- which looks to solve the root cause of machinery failures or extend
the life of machinery through proactive practices such as precision alignment, precision
balancing, improved specifications and better operating practices. Proactive maintenance
practices focus on the relentless pursuit of equipment condition assessment to ensure the
reliability of a machine. Reactive maintenance practices focus on the quick response to
machinery failures rather on focusing on the extension of machinery life through proactive,
preventive and predictive maintenance activities.

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Worksheet 1.1.3 : Identifying Planning Method and Stages

Learning outcomes:
1 Plan and Prepare the Workplace
Learning Activity:
1.1 Plan the Maintenance and Repair Job

Read the instructions carefully; be sure to answer the questions fully before going to the next
activity.

1. The list below shows the activities for planning a maintenance and repair job.
a. List the stages into which the activities are divided.
b. What planning method would be particularly appropriate for this maintenance and

repair job.

Activity Description

1 Include shutdown in annual plan and budget

2 Information from inspections and preventive maintenance

3 Information from earlier maintenance operations

4 Information from deferred maintenance

5 Additional requirements of the production department and other departments

6 Information from breakdown analyses

7 Evaluation meeting by the production engineering department and electrical engineering

department

8 Drawing up the activity list with repair reports.

9 Determining the required number of man hours

10 Hiring additional personnel

11 Contracting out work

12 Requesting information from documentation

13 Ordering special parts (components)

14 Ordering materials

15 Issuing work orders

16 Progress meetings to check the deliveries of materials and parts

17 Detailed planning

18 Overall planning

19 Start execution

20 Replacing or repairing parts and other defects found

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Worksheet 1.1.3 : Identifying Planning Method and Stages

21 Ordering additional parts and materials
22 Making parts and installing them
23 Collecting overhaul information for the files
24 Progress monitoring during the overhauls
25 Test run of the repaired plant
27 Evaluation of the overhaul with the personnel concerned
28 Writing the evaluation reports and maintenance checklist including the information in the
equipment files

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Information Sheet 1.3.1 : Safety Guidelines and Procedures Sample (Oil and Gas)

Learning outcomes:

1 Plan and Prepare the Workplace

Learning Activity:

1.3 List safety and precaution guidelines needed in conducting Maintenance and Repair
Job.

Refinery Safety Rules and Regulations

1. Smoking

1.1 Smoking for all personnel within the Refinery is prohibited.

1.2 Cigarette butts seen within a particular area whether at the workplace or

inside the office shall be deemed theirs. Check area before start of work.

1.3 Cigarettes and matches/lighters are not allowed inside the Refinery.

2. Hot Work

2.1 All hot work shall be covered with duly approved Hot Work permit.

2.2 Gas testing is required prior to issuance of Hot Work permit whether it is initial

or renewal.

2.3 Hot Work permit validity is 8 hours and shall be renewed before expiration.

2.4 Refinery personnel may revoke Hot Work permit anytime if the area

condition is found unsafe for hot work. Work area condition may change due

to operational consideration.

2.5 Stop hot work, shut off all running equipment being used and report to

Refinery personnel immediately upon observing unsafe conditions in the

work area or nearby area.

2.6 Comply strictly with the requirements stated in the Hot Work permit before,

during and after work activities.

2.7 Seal sewers and drains within radius of 15 m.

2.8 Clear away any flammable material in the work area.

2.9 Adequate cleaning of work piece is essential before the hot work

commences to remove heavy substance such as lubricating oils, fuel oils, oily

residues, bitumen residues. The application of heat (e.g. welding and cutting

equipment) to such heavy materials may produce flammable vapors

caused by either vaporization or thermal cracking.

2.10 A fully charged 20lb dry chemical type fire extinguisher must be provided for

every hot work location which can be used in case of fire.

2.11 Welding machines, portable air compressors, generators, etc. shall have

10lb C02 or 20lb dry chemical type fire extinguisher located adjacent to

the equipment in addition to Item 2.10.

2.12 A fire watch must be provided during welding and grinding works to

extinguish molten slags and sparks using water hose. Install B/V to control

water flow from fire hydrant.
2.13 Before using fire hydrants, advise Safety Section by accomplishing “Request to

Use Fire Hydrant” form. Install B/V to control flow.

2.14 Remove welding or burning torches from vessels at the end of work period. If

removal is impractical, the hose at the regulator shall be disconnected.

2.15 Vent and clear any hollow or partially hollow vessel or equipment which

may be over-pressured by the application of heat before heating or burning into

it.

2.16 Do not weld on oil or gas lines or equipment in service unless there is an

internal cooling agent to remove heat, such as flowing of liquid or gas, and/or

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Information Sheet 1.3.1 : Safety Guidelines and Procedures Sample (Oil and Gas)

unless there is sufficient metal to prevent burn-through.
2.17 Before execution of any critical activities such as hot tapping, box-in, etc.

they shall be coordinated with project administrator and operations
personnel to identify procedures and safety requirements applicable.
3. Compressed gas cylinders and cutting equipment
3.1. Compressed gas cylinders, empty or full, shall be adequately secured in
an upright position when in transport, storage and use.
3.2. If there are no facilities in the area for securing the cylinder in the upright
position, the cylinder should he placed on its side and blocked to keep it
from rolling.
3.3. Do not store cylinders under pipe, power lines of near heat sources.
3.4. Protective caps must be kept in place when cylinders are not in use.
3.5. Avoid rough handling of cylinders such as dropping or rolling.
3.6. Oxygen and acetylene cylinders must not be placed inside a vessel.
3.7. Inspect oxy-acetylene hoses and connections to gages and cutting torch
before using.
3.8. Do not fasten hoses to gages and cutting torches with tie-wires. Machine
crimp or use screw clamps to connect hoses.
3.9. Do not use defective pressure regulator gauges.
3.10. Do not use compressed gas to clean clothing or body.
3.11. Do not release hazardous compressed gas into confined spaces.
3.12. Do not use oxygen or acetylene for testing purposes.
4. Electrical Tools and Equipment
4.1 Properly ground portable electrical tools and equipment.
4.2 Never ground a welding cable to the wall of the pipe that is in service or to
an equipment or vessel ladder.
4.3 Do not use naked lights. Provide safety guard and globe.
4.4 Explosion-proof portable lights and convenience outlet must be used
where hot work is not authorized.
4.5 Inspect extension cord of any insulation defects. Discard defective ones.
4.6 Inspect and test electrical equipment and tools before using.
4.7 Non-intrinsically safe radios, cell phones and other electronic device as
are not allowed inside the Refinery.
4.8 Cameras are not allowed inside the Refinery.
5. Plant Air
5.1 Do not use compressed air for cleaning lines or sewers.
5.2 Do not use plant system compressed air for breathing purposes.
6. Scaffolding and Ladders
6.1 Install scaffold per Refinery Standard on Scaffoldings.
6.2 Adequately secure wooden planks.
6.3 Do not use drum or pipings as staging to reach elevated vessel or piping
components.
6.4 Use only ladders that are in good condition. Always inspect ladder before
use. Check for missing rungs, loose stay rods and any splitting or
other damage to the side rails.
6.5 If the ladder is not equipped with pivoting feet, or there is a question of
slippage, they must be either held or lashed securely while in use.
6.6 Where electrical hazards are present, metal or aluminum ladders should not
be used.
6.7 Do not place ladder where it can be bumped, such as in front of a door, in

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Information Sheet 1.3.1 : Safety Guidelines and Procedures Sample (Oil and Gas)

the street or aisles, etc. unless adequate precautions are taken to protect
both the climber and others who may be in the area.
7. Clothing and Personal Protective Equipment
7.1 Always wear hard hat upon entering the Refinery Gate.
7.2 Wear dust mask to prevent inhalation of dust particles during activities that
create air-borne particles such as metal surface brushing, insulation works,
castable or concrete works, etc. Towel or shirt wrapped around the face is
not allowed during power brushing.
7.3 Wear respiratory protective equipment such as cartridge respirators where
atmosphere of the work area is contaminated with hazardous toxic gases,
vapors or fumes and SCBA or air-line where an oxygen deficiency exists.
7.4 Wear goggles or face shield to protect the eyes from flying particles during
grinding, brushing, cutting, drilling, filing and turning activities.
7.5 Use working gloves as basic hand protection. Leather gloves are worn for
rough jobs. Long rubber gloves are used for handling chemicals.
7.6 Only safety shoes is allowed inside the Refinery.
7.7 Wear appropriate working clothes such as long sleeve maong jacket
during steam rodding, draining or blinding activities or working in areas
where the probability of exposure to hot liquids, flash fires or skin irritants exists.
Do not wear clothes made of nylon or materials that easily burn or shrink
when heated. Wear only 100% cotton clothing material.
7.8 Use protective suits to protect skin during chemical cleaning of equipment
or when there is a probability of exposure to acid, caustic or other
hazardous materials.
7.9 Use body harness attached to an independently supported lifeline when
working 6 feet above the ground or when working inside a vessel where
the atmosphere does not support life or immediately hazardous to life.
7.10 Wear ear plugs or muffs while working in areas with noise warning signs.
7.11 Wear life vest when working directly over water, such as under the docks
or from a boat.
7.12 Do not wear clothing saturated with oil, hazardous liquid or chemicals.
7.13 Use eye wash and emergency shower as needed. Do not use them for
drinking and cleaning purposes.
7.14 Loose clothing , loose sleeves or gloves should not he worn where there is
a probability of their being caught in moving or rotating machines.
8. Housekeeping/garbage disposal
8.1 At all times job site shall be kept clean and free from debris, trash and
rubbish.
8.2 Clean up area before start of work or quitting.
8.3 Do not allow garbage to accumulate at job site.
8.4 Store all materials in a neat and orderly fashion.
8.5 Keep aisles, passageways, stairs, platforms and ladders clear of all
unnecessary obstructions.
8.6 Segregate garbage according to pyrophoric and non-pyrophoric (metals,
etc.) materials. Pyrophoric materials should be buried under ground at
dumpsite.
8.7 Collect pyrophoric materials in drums and must be kept wet awaiting
disposal.
8.8 Secure permit to dispose garbage at Dumpsite from OM&S.
8.9 Do not block fire fighting equipment such as fire monitors and hydrants

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Information Sheet 1.3.1 : Safety Guidelines and Procedures Sample (Oil and Gas)

with garbage, materials and equipment.
8.10 Any material, trash or debris that falls from Refinery’s vehicle shall be

promptly cleaned up by Refinery.
9. Driving any vehicle inspection

9.1 Drivers must comply with REFINERY requirements to be authorized to drive
in the Refinery by submission of copy of valid LTO drivers’ license and
certificate of competence.

9.2 Vehicles must pass Quarterly Vehicle Safety Inspection conducted by Safety
Section to be allowed entry at the Refinery. Copies of Vehicle Certificate of
Registration and Official Receipt must be submitted to Safety Section.

9.3 Regular vehicle inspection should be conducted to ensure its reliability.
9.4 Drivers and equipment operators must check vehicle/equipment before

usage.
9.5 Vehicle and equipment are not allowed to enter operating units and tank

farms without securing permit from Operations. Vehicles entering these
areas may be required to have spark-proof mufflers or their equivalent.
9.6 Drivers and equipment operators must obey Refinery traffic signs (STOP,
YIELD, SLOW DOWN, Speed Limit, etc.).
9.4 Slow down and sound horn while approaching a blind curve or corner.
9.5 Park Vehicle at designated parking areas only. No parking at yellow
painted gutter/lane.
9.6 Do not block fire hydrants/fire fighting equipment.
9.7 Set parking brake/chokes before leaving the vehicle. Observe correct
position of wheel when parking downhill.
9.8 Do not back off vehicle unless way is clear. If unable to see behind of the
vehicle, ask another person to guide while backing off.
9.9 Overloading is not allowed. No more than 3 persons including the driver
are allowed in the front seat of vehicle. Maximum of 8 and 6 persons are
allowed at the bed of single cab and double cab, respectively.
9.1 0 Do not sit on the edge of the vehicle. Vehicle should be provided with
bench and side railings.
9.11 Hang a red flag on loads extending beyond the front, sides or rear of the
vehicle.
10. Warning/Caution Signs and Guarding
l 0.1 Personnel shall obey all safety warning signs and shall provide or wear
safety equipment required by signs.
10.2 Provide adequate barricade and warning signs during rig-up of
materials/equipment.
10.3 Guard or protect any area into which materials or tools are to be deliberately
dropped or thrown.
10.4 Guard or place appropriate barricades and warning signs around temporary
openings in floors, excavations, etc. to prevent accident. Provide steel plate
cover on open excavations before leaving it.
10.5 Replace permanent handrails and guardrails immediately after need for
entry has ended.
10.6 Guards on moving machinery shall be in placed or other protection
provided before such machinery is operated.

11. Walks and Roadways
11.1 Pass thru walks and roadways designated for the use of personnel when

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Information Sheet 1.3.1 : Safety Guidelines and Procedures Sample (Oil and Gas)

entering or leaving the job site or when moving from one area to another.
11.2 Use of short cuts or non-designated pathways is prohibited.
11.3 Emergency stairways are used during emergencies only.
11.4 Always use pedestrian lanes and side walks
12. Fires
12.1 All personell shall stay in their work place in case of fire unless fire is

within the vicinity wherein they should vacate the area and move to a
safer ground upwind.
12.2 In case of fire caused by personnel or by their equipment, they are
expected to put out the fire using their stand-by fire extinguisher or water
hose that are provided during hot work. Report to Refinery personnel at
once any fire incident and secure assistance.
13. Lifting and Lifting Equipment
13.1 Lifting equipment such as cranes should have third party inspection
certificate.
13.2 Operators must comply with REFINERY requirements to be authorized to
operate heavy equipment in the Refinery by submission of copy of valid LTO
drivers license and certificate of competence.
13.3 Provide sufficient lighting when rigging materials/equipment during night
time.
13.4 Do not move loads suspended from mobile equipment without load being
secured to prevent swinging.
13.5 Do not use railing as a support for material or rigging.
13.6 Do not ride on blocks, hooks, balls or crane loads unless a safety belt,
sling or bosun chair is provided.
13.7 When it is necessary to operate cranes or perform work within 12 feet of
open electric lines, consult Refinery personnel and determine whether
the electric lines can be de-energized. Otherwise, provide suitable guards
of approved type to prevent its equipment from coming into
contact with the electric cable.
14. Hand Tools, Power Tools and Machinery
14.1 Always inspect tools prior use. Do not use defective tools.
14.2 Do not subject tools to undue stress or use them for purposes for which
they are not designed.
14.3 Do not work on any machinery while it is in motion. If it is impractical to
shut equipment down before working on it, secure Refinery approval before
proceeding.
14.4 Do not stand in line with high speed grinding wheels. Guard shall be provided.
14.5 Only Refinery Operations personnel are allowed to start-up or shutdown any
Refinery process equipment.
15. Safety Reports
15.1 A regular Safety Officer shall be at the job site at all times during the
execution of work.
15.2 Safety talks shall be conducted before the start of work every week.
Submit Safety Talk Review sheet to REFINERY Safety Section not later than
2nd day of each week.
15.3 Submit Monthly Manhours and Incident Summary before the 7th day of the
following month to REFINERY Safety Section.
15.4 All incidents must be reported to REFINERY Safety Section by
accomplishing the Incident Report form within 24 hours.

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Information Sheet 1.3.1 : Safety Guidelines and Procedures Sample (Oil and Gas)

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Worksheet 2.1.1 : Basic Control System, Process Variables-Review

Learning outcomes:
2 Maintain Instrumentation and Control Devices
Learning Activity:
2.1 Identify Types of Process Control System
I. Write the answer on the blank provided at the end of the statement or question.
1. Devices used to measure and control an industrial process._________________
2. A physical or chemical quantity in an industrial process that can be measured and can change.
For example, you can measure flow rate, pressure, temperature, level, etc. _______________
3. Component of an automatic Control System that measures the process and transmit signal
proportional to process condition to controller.__________________
4. Component of an automatic control system that directly regulates the flow of energy or material
to the process.__________________
5. It is used to describe a control situation in which process variables are manipulated to bring
about a balance between supply and demand on the process.____________________

II. Answer the questions briefly.

1. What is an indirect level measurement?

___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

2. How does an open-loop control system differ from a closed-loop control system?

___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

3. How many process connections do differential pressure measurement instruments have?

___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #

Control Devices July 07, 2010 1

Information Sheet 2.1.2: Process Control System

Learning outcomes:
2 Maintain I & C Devices
Learning Activity:
2.1 Identify Process Control System

In this information sheet, you will learn about how control components and control algorithms
are integrated to create a process control system. Because in some processes many variables
must be controlled, and each variable can have an impact on the entire system, control
systems must be designed to respond to disturbances at any point in the system and to
mitigate the effect of those disturbances throughout the system.

Feedback and Feedforward Loops

Control loops can be divided into two categories: feedback loops and feedforward loops.

Feedback Control

A feedback loop measures a
process variable and sends the
measurement to a controller for
comparison to setpoint. If the
process variable is not at setpoint,
control action is taken to return the
process variable to setpoint. Figure
2.1.1 illustrates a feedback loop in
which a transmitter measures the
temperature of a fluid and, if
necessary, opens or closes a hot
steam valve to adjust the fluids’
temperature.

Figure 2.1.1 Feedback Loop

Feedback loops are commonly used in the process control industry. The advantage of a
feedback loop is that it directly controls the desired process variable. The disadvantage to
feedback loops is that the process variable must leave setpoint for action to be taken.

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Control Devices July 07, 2010

Information Sheet 2.1.2: Process Control System Figure 2.1.2 Feedforward Control Loop

Feedforward Control

Feedforward control is a control system that
anticipates load disturbances and controls
them before they can impact the process
variable. For feedforward control to work, the
user must have a mathematical
understanding of how the manipulated
variables will impact the process variable.
Figure 2.1.2 shows a feedforward loop in
which a flow transmitter opens or closes a
hot steam valve based on how much cold
fluid passes through the flow sensor.

An advantage of feedforward control is that error is prevented, rather than corrected. However,
it is difficult to account for all possible load disturbances in a system through feedforward
control. Factors such as outside temperature, buildup in pipes, consistency of raw
materials,humidity, and moisture content can all become load disturbances and cannot always
be effectively accounted for in a feedforward system.

In general, feedforward systems should be used in cases where the controlled variable has the
potential of being a major load disturbance on the process variable ultimately being controlled.
The added complexity and expense of feedforward control may not be equal to the benefits of
increased control in the case of a variable that causes only a small load disturbance.

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Control Devices July 07, 2010

Information Sheet 2.1.2: Process Control System
Feedforward Plus Feedback

Because of the difficulty of accounting

for every possible load disturbance in

a feedforward system, feedforward

systems are often combined with

feedback systems. Controllers with

summing functions are used in these

combined systems to total the input

from both the feedforward loop and

the feedback loop, and send a unified

signal to the final control element.

Figure 2.1.3 shows a feedforward- Figure 2.1.3 Feedforward-plus feedback
plus-feedback loop in which both a Control Loop

flow transmitter and a temperature transmitter provide information for controlling a hot steam

valve.

Control Applications

While each application has its own characteristics, some general statements can be made
about pressure, flow, level, and temperature loops.

Pressure Control Loops

Pressure control loops vary in
speed—that is, they can respond to

changes in load or to control action

slowly or quickly. The speed

required in a pressure control loop

may be dictated by the volume of

the process fluid. High-volume

systems (e.g., large natural gas

Figure 2.1.4 Pressure Control Loop

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Control Devices July 07, 2010

Information Sheet 2.1.2: Process Control System
storage facilities) tend to change more slowly than low-volume systems (Figure 2.1.4)

Flow Control Loops

Generally, flow control loops are

regarded as fast loops that respond to

changes quickly. Therefore, flow control

equipment must have fast sampling and

response times. Because flow

transmitters tend to be rather sensitive

devices, they can produce rapid

fluctuations or noise in the control

signal. To compensate for noise, many

flow transmitters have a damping

function that filters out noise. Sometimes, Figure 2.1.5 Flow Control Loop
filters are added between the transmitter

and the control system. Because the temperature of the process fluid affects its density,

temperature measurements are often taken with flow measurements and compensation for

temperature is accounted for in the flow calculation. Typically, a flow sensor, a transmitter, a

controller, and a valve or pump are used in flowontrol loops (Figure 2.1.5).

Level Control Loops

The speed of changes in a level control

loop largely depends on the size and

shape of the process vessel (e.g.,

larger vessels take longer to fill than

smaller ones) and the flow rate of the

input and outflow pipes. Manufacturers

may use one of many different

measurement technologies to

determine level, including radar,

ultrasonic, float gauge, and pressure Figure 2.1.6 Level Control Loop
measurement. The final control element

in a level control loop is usually

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Control Devices July 07, 2010

Information Sheet 2.1.2: Process Control System
a valve on the input and/or outflow connections to the tank (Figure 2.1.6). Because it is often
critical toavoid tank overflow, redundant level control systems are sometimes employed.
Temperature Control Loops
Because of the time required to change the temperature of a process fluid, temperature loops
tend to be relatively slow. Feedforward control strategies are often used to increase the speed
of the temperature loop response. RTDs or thermocouples are typical Temperature sensors.
Temperature transmitters and controllers are used, although it is not uncommon to see
temperature sensors wired directly to the input interface of a controller. The final control
element for a temperature loop is usually the fuel valve to a burner or a valveto some kind of
heat exchanger. Sometimes, cool process fluid isadded to the mix to maintain temperature
(Figure 2.1.7).

Figure 2.1.7 Temperature Control Loop

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Control Devices July 07, 2010

Information Sheet 2.2.1 : Control Valve Maintenance

Learning outcomes:
2 Maintain I & C Devices
Learning Activity:
2.2 Identify I & C Device Working Principle
Replacing Actuator Diaphragm

After isolating the valve from all pressure, relieve all spring compression in the main spring, if
possible. (On some spring and diaphragm actuators for use on rotary-shaft valve bodies.
spring compression is not externally adjustable. Initial spring compression is set at the factory
and does not need to be released in order to change the diaphragm.) Remove the upper
diaphragm case. On direct-acting actuators, the diaphragm can be lifted out and replaced with
a new one. On reverse-acting actuators, the diaphragm head assembly must be dismantled to
change the diaphragm.

Most pneumatic spring-and-diaphragm actuators utilize a molded diaphragm for control valve
service. The molded diaphragm facilitates installation, provides a relatively uniform effective
area throughout the valve's travel range, ad permits greater travel than could be possible if a
flat-sheet diaphragm were used. If a flat-sheet diaphragm is used in an emergency repair
situation, it should be replaced with a molde diaphragm as soon as possible.

When re-assembling the diaphragm case, tighten the cap screws around the perimeter of the
case firmly and evenly to prevent leakage.

Replacing Stem Packing

Bonnet packing, which provides the pressure seal around the stem of a globe-style or angle-
style valve body, may need to be replaced if leakage develops around the stem, or if the valve
is completely disassembled for other maintenance or inspection. Before starting to remove
packing nuts, make sure there is no pressure in the valve body.

If the packing is of the split ring variety, it can be removed (with considerable difficulty) without
removing the actuator by digging it out of the packing box with a narrow, sharp tool. This is not

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Control Devices July 07, 2010

Information Sheet 2.2.1 : Control Valve Maintenance

recommended, because the wall of the packing box or the stem could easily be
scratched,thereby causing leakage when the new packing was installed.

Don't try to blow out the old packing rings by applying pressure to the lubricator hole in the
bonnet. This can be dangerous and frequently doesn't work very well anyway. (Many packing
arrangements have about half of the ring below the lubricator opening.)

The approved method is to :
1. Separate the valve stem and actuator stem connection.
2. Remove the actuator from the valve body.
3. Remove the bonnet and pull out the valve plug and stem.
4. Insert a rod (preferably slightly larger than the stem) through the bottom of the packing box
and push or drive the old packing out the top of the bonnet.
(Don't use the valve plug stem because the threads could be damaged in the process.)
5. Clean the packing box. Inspect the stem for scratches or imperfections that could
damage new packing.
6. Check the valve plug, seat ring, and trim parts as appropriate.
7. Re-assemble the valve body and put the bonnet in position.
8. Tighten body/bonnet bolting in sequence.
9. Slide new packing parts over the stem in proper sequence, being careful that the stem
threads do not damage the packing rings.
10. Install the packing follower, flange, and packing nuts.
11. For spring-loaded TFE V-ring packing, tighten the packing nuts as far as they will go.
For other varieties, tighten in service only enough to prevent leakage.
12. Replace and tighten the actuator onto the body. Position and tighten the stem
connector to provide desired valve plu travel.

Replacing Threaded Seat Rings

Many conventional sliding-stem control valves use threaded-in seat rings. Severe service

conditions can cause damage to the seat ring(s) so that the valve does not shut off

satisfactorily. In that event, replacement of the seat ring(s) will be necessary. Before trying to

remove the seat ring(s), check to see if the ring has been tack-welded to the valve body. If so,

cut away the weld and apply penetrating oil to the seat ring threads before trying to remove the

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Control Devices July 07, 2010

Information Sheet 2.2.1 : Control Valve Maintenance

ring. The following procedure for seat ring removal assumes that a seat ring puller, such as
that shown in Figure 5-4, is being used. If a puller is not available, a lathe or boring mill may be
used to remove the ring(s).

1. Place the proper size seat lug bar across the seat ring so that the bar contacts the seat lugs
as shown.
2. Insert drive wrench and place enough spacer rings over the wrench so that the hold down
clamp will rest about 1/4-inch above the body flange. Slip hold-down clamp onto drive wrench
and secure the clamp to the body with two cap screws (or hex nuts for steel bodies) from the
bonnet. Do not tighten cap screws or nuts.
3. Use turning bar to unscrew the seat ring. Stuck seat rings may require additional force on
the turning bar. Slip a 3-to 5-foot length of pipe over one end of the turning bar, and while
applying a steady force, hit the other end of the bar with a heavy hammer to break the ring
loose.
In addition, a large pipe wrench can used on the drive wrench near the hold-down clamp.
4. After the seat ring is loose, alternately unscrew the flange bolts (or nuts) on the hold-down
clamp and continue to unscrew seat ring.
5. Before installing new ring(s), thoroughly clean threads in the body port(s).Apply pipe
compound to the threads of the new seat ring(s).

NOTE : On double-port bodies, one of the seat rings is smaller than the other. On direct-
acting valves (push-down-to-close action), install the smaller ring in the body port farther
from the bonnet before installing the larger ring. On reverse-acting valves (push-down-to-
open action), install the smaller ring in the body port closer to the bonnet before installing the
larger ring.

Screw the ring(s) into the body. Use the seat ring puller, lathe, or boring mill to tighten seat ring
in the body. Remove all excess piping compound after tightening. The seat ring can be spot
welded in place to ensure that it does not loosen.

6. Reassemble the Valve

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Control Devices July 07, 2010

Information Sheet 2.2.1 : Control Valve Maintenance
Grinding Metal Seats

A certain amount of leakage should be expected with metal-to-metal seating in any globe-style
valve body.If the leakage becomes excessive, however, the condition of the seating surfaces
of the valve plug andseat ring can be improved by grinding. Large nicks should be machined
out rather than ground out. Many grinding compounds are available commercially. Use one of
good quality or make your own with a mixture of 600-grit silicon carbide compound and
solidified vegetable oil. White lead should be applied to the seat to prevent excessive cutting or
tearing during grinding. In cage-style constructions the bonnet or bottom flange must be bolted
to the body with the gaskets in place during the grinding procedure to position the cage and
seat ring properly and to help align the valve plug with the seat ring. A simple grinding tool can
be made from a piece of strap iron locked to the valve pluge stem with nuts.

On double-port bodies, the top ring normally grinds faster tha the bottom ring.Under these
conditions, continue to use grinding compound and white lead on the bottom ring,but use only
a polishing compound (rottenstone and oil) on the ring. If either of the ports continues to leak,
use more grinding compound on the seat ring that is not leaking and polishing compound on
the other ring. This procedure grinds down the seat ring that is not leaking until both seats
touch at the same time. Never leave one seat ring dry while grinding the other. After grinding,
remove bonnet or bottom flange, clean seating surfaces, and test for shutoff. Repeat grinding
procedure if leakage is still excessive.

Lubricating Control Valve Packing

A lubricator or lubricator/isolating valve (as shown in Figure 5-5) is required for semi-metallic

packing and is recommended for graphited asbestos and TFE-impregnated asbestos packing .

The lubricator or lubricator/isolating valve combination should be installed on the side ofthe

valve bonnet, replacing the pipe plug used with packing types not rquiring lubrication. Use Dow

Corning X-2 lubricant or equivalent for standard service up to 450°F (232°C) and Hooker

Chemical Corporation Fluorolube lubricant or equivalent for chemical chemical service up to

300°F(149°C).With lubricator, isolating valve, and pipe nipple (if used) completely filled with

lubricant and installed on bonnet, open isolating valve (if used) and rotate lubricator bolt a full

turn clockwise to force lubrcant into the packing box. Close the isolating valve after each

lubrication. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Code No.

Control Devices July 07, 2010

Information Sheet 2.2.1 : Control Valve Maintenance
Adjsting Travel and Connecting Stem

Sliding-Stem Control Valves
Part names used throughout the following section are shown in Figure 5-6. The procedure is
appropriate for slidingstem valves with either spring-and-diaphragm or piston actuators.When
performing the travel adjustment procedure, be careful to avoid damaging the valve plug stem.
Scratches on the stem can lead to packing leakage. If the unit includes a bellows seal bonnet,
the stem must not be rotate or the bellows will be damaged. On all other units, the stem may
be rotte for minor travel adjustment, but the valve plug should not be in contact with the seat
ring during rotation of the stem.

1. Assemble the body and mount the actuator. Screw the stem locknuts onto the valve plug
stem and set the travel indicator disc on the locknuts with the "cupped" portion downward.
Leave enough threads exposed above the disc for the stem connector.
2. Be sure the actuator stem is in the position that equates with the "closed" valve plug
position-flly "down" for push-down-to-close valve styles; fully "up"for push-down-to-open valve
styles. To achieve this condition, it will often be necessary to pressure load the actuator to
properly position the stem.
3. Move the valve plug to the "closed" position, contacting the seat ring.
4. Change actuator loading pressure in oder to move the actuator stem 1/8-inch.
Install the stem connector, clamping the actuator stem to the valve plug stem.
5. Cycle the actuator to check availablity of desired otal travel and that the valve plug sats
before the actuator contacts the upper travel stop. Minor adjustments in total travel can be
made, if necessary, by loosening the stem connector slightly, tightening the locknuts together,
and screwing the stem either into or out of the stem connector by means of a wrench on the
locknuts.If overall travel increase is desired, the increase must be less than the 1/8-inch the
actuator rod was moved in step 4 above, or the valve will not shut off.
6. If the total travel is adequate, tighten the stem connector securely, lock the travel indicator
disc against the connector with the locknuts, and adjust the indicator plate on the yoke to show
valve plug poisition.
7. Provide a gauge to measure the pressure to the actuator. Make a final adjustment on the
actuator or its positioner to set the starting point of valve travel and to obtain full travel for
the desired instrument range.

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Control Devices July 07, 2010

Information Sheet 2.2.1 : Control Valve Maintenance

Rotary-Shaft Control Valves

There are a variety of actuator mounting styles and position possible with rotary-shaft control
valve bodies. Specific adjustment procedures vary depending on whether desired valve action
is push-down-toclose or push-down-to-close or push-down-to-open. The connecting linkage
between the actuator and the valve body normally includes a lever which is attached to the
valve shaft by means of a key and keyway slot or by mating multiple cut splines on the lever
and shaft. A rod end bearing and turnbuckle usually connect the lever to th actuator stem. The
valve shaft and disc or V-notched ball are stamped with indicating marks to show proper
orientation for mating splines. Similar indicating marks are used to show shaft and lever
orientation. Fine adjustment is accomplished by lengthening or shortening the turnbuckle to
achieve full disc or V-notch ball closure at 0o indicated rotation.

For disc-style rotary vaalves, fine travel ajustment should be performed with the valve body
out of the pipline so that measurements can be made as suggested in Figure 5-9. Refer to the
manufacturer's instruction manuals for specific adjustment details for the body and actuator
being used.

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Operation Sheet 2.2.2 : Threaded and Wafer Style Flowmeters Operation and
Maintenance

Learning outcomes:
2 Maintain I & C Devices
Learning Activity:
2.2 Identify I & C Device Working Principle
Principle of Operation

These threaded and wafer style flow meters measure flow rate by
sensing the pressure differential created across a calculated flow nozzle
which is machined in the body of the flow meter. A pair of matched,
opposed bellows sense the differential pressure and drive a mechanical
linkage and gear movement to indicate flow rate directly on the dial.
(When fitted with a blind transmitter or digital display readout, the
bellows and mechanical linkage are replaced with a solid state
differential pressure sensor).

Select a site which is convenient for viewing and which provides service
access to the front and rear of the flow meter. Note that the dial can be
ordered in any orientation at 90° increments and can be easily reoriented in the field. See
"Changing the Dial Orientation" in the installation section. the site selected should provide at
least 10 diameters of straight meter size pipe between the flow meter inlet and any upstream
fitting such as elbow, tee or valve. There are no special piping requirements for the
downstream connections to the flow meter.

Note that the flow meters are calibrated based on schedule 40 pipe connections. Tubing or
hoses do not have the same ID as pipe and should be transitioned to pipe at least 10
diameters upstream of the flow meter to achieve rated accuracy.

Preventive Maintenance

The flow meter does not require routine lubrication or service of any kind. Keep the indicator of
the flow meter housing clean and free of dust, moisture, oils or corrosive materials. Protect the
flow meter from dripping or splashing corrosives or solvents which may attack flow meter
exterior and eventually damage the internal mechanism.

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Control Devices July 07, 2010

Operation Sheet 2.2.2 : Threaded and Wafer Style Flowmeters Operation and
Maintenance

Checking Zero

Water hammer or pressure surges can displace the bellows and
cause the zero to shift. If the pointer does not return to the reference
point when flow through the flow meter is zero, or if the pointer does
not move away from the zero reference mark at 12-15% of full scale Zero Mark
flow, then check the zero adjustment as follows:

 Stop flow.

 Remove the lens.

 Observe the position taken by the pointer. When properly adjusted, the pointer should
point to the zero reference mark as shown in Figure 4.

 If the pointer is positioned within 1/2" (12mm) of the zero reference mark, then follow the
FINE ADJUSTMENT procedure to re-zero the flow meter.

 If the pointer is positioned more than 1/2" (12mm) from the zero reference mark, then
follow the COARSE ADJUSTMENT procedure.

Checking the Pointer Reload

If the fine adjustment has been performed repeatedly, the pointer return spring preload
should be checked. Manually rotate the pointer CCW toward full scale. The pointer
should stop at full scale. If the pointer goes beyond full scale, make adjustments by
following the COARSE ADJUSTMENT procedure. Otherwise, go to the FINE
ADJUSTMENT procedure. FINE ADJUSTMENT is made by placing a blade screwdriver
in the pointer slot hub. Grip the pointer close to the hub on both sides of the hub and
rotate the screwdriver in small increments and release each time to check position,
repeat if necessary or until the pointer rests at the zero reference mark.

Coarse Zero Adjustment

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Control Devices July 07, 2010

Operation Sheet 2.2.2 : Threaded and Wafer Style Flowmeters Operation and
Maintenance

If necessary, restore spring preload first before Proceeding with the Coarse
Adjustment procedure.

0.02"-0.05"
Zero Reference point dial

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Control Devices July 07, 2010

Information Sheet 3.1.1 : Work Instruction Sample

Learning outcomes:
3 Maintain I & C Devices
Learning Activity:
3.1 Read and Interpret work instruction for maintenance job.

Common Parts of a Work Instruction for Maintenance/Repair Job:

 Work Instruction Title
 Purpose and Scope
 Hazards
 References
 Terms and Conditions
 Materials and Equipment
 Responsibilities
 Work Instruction/Activity
 Attachments

Work Instruction for Bench Calibration Checks of
Differential Pressure Switch

Work Instruction No: MTC-PS15-W01

Purpose and scope
To introduce a standardised & systematic approach to the Test Bench checking of
Pressure & Differential Pressure Switches and confirm that the same are functioning as
per relevant setting value.

Hazards
Ensure that the Instrumentation Department is aware about work being carried out and also
that the requested activity is made according to relevant instructions.
Ensure that instrument technical features are suitable for to applying the confirmed and / or
modified setting data.

References
Rosemount Switches Operation / Maintenance Instruction Manual
Refer to MTC-PR-012 for terms and conditions

Terms and Definitions
PS / DPS – Pressure Switch / Differential Pressure Switch
DWT - Dead Weight Tester

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Control Devices July 07, 2010

Information Sheet 3.1.1 : Work Instruction Sample

TBPC - Test Bench Pressure Calibrator

Materials and Equipment

Test Equipment to be used includes:

TRADINCO Instrument Model L 1300 / 1 Dead Weight Tester ( range 0-140 Bar )

( to be used only for instrument where the Tester oil is compatible with Process Fluid -

or DRUCK DP 610 Test Bench Pressure Calibrator ( range 0-1 Bar )

-or DRUCK DP 610 Test Bench Pressure Calibrator ( range 0-10 Bar )

-or DRUCK DP 610 Test Bench Pressure Calibrator ( range 0-100 Bar )

and FLUKE Fluke 77 Digital Multimeter

GYROLOOK Standardized Connection Fittings

Standard pressure leads PVC black tube for LP ( up-to 7Bar ) or HP ( more than 7 Bar )

Standard hand tools ref : MTC-PR15-T01

Responsibilities

Workshop Instrument Supervisor responsible for execution of test and calibration activities,
to guarantee that job is performed correctly and to assure the issuing of Calibration Sheet
and the recording of tests performed on Instrument Log Book.

Test and Calibration activities are performed according to request and instruction issued
by Field Instrumentation Head ( PEI / 2 )

Work instruction / ACTIVITY

See overleaf

STEP INSTRUCTION/ ACTIVITY SIGN
1
2 Obtain work request and instruction from Instrumentation
Supervisor
3 Refer to Data Sheet in order to check the instrument physical
4 characteristics and D.W. Tester oil compatibility with its relevant
Process fluid.
5 Basically all Instrument used on Utilities are suitable for re-
calibration check with
D.W. Tester, while for Instrument used on Gas and LNG process
must be tested with Only dry instrument air or nitrogen.
Check and inspect the internal housing parts of the Instrument and
clean / remove
corrosion and moisture if required.
To check Pressure Switch calibration with the Dead Weight
Tester oil, connect it with a suitable connection fitting and
without any pressure applied, check the status of relevant
switch
applying the electrical connection leads of multimeter to the
switch terminals
In case of Differential Pressure Switch the instrument HP side only
have to be
connected while, the LP side shall remain “open” to the
atmosphere

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Control Devices July 07, 2010

Information Sheet 3.1.1 : Work Instruction Sample

6 Close the D.W. Tester vent, apply the increasing pressure up-to the
setting and check when switch status change ( from “Close” to
“Open” contact or vice versa ).

7 Release the D.W. Tester pressure by vent and check the switch
resetting pressure (return to the initial position)

8 If the switch change status is not correct at supposed pressure
value, repeat the test and then setting must be adjusted following
instructions of manufacturer Operation/Maintenance Manual

9 After adjusting of Set point, the switch Reset have to be check and
adjusted as per
Data Sheet or Manufacturer instructions.

10 Switches pressure setting can be done at the Rising Pressure (
“set” at High Point
and “Reset” at Low Point ) or at the Failing Pressure ( “set” at Low
Point and Reset
at the High Point ) according to the switch setting instruction.

11 After execution of switch setting, the instrument “repeatability” have
to be check with a repetition of increasing / decreasing pressure
cycles in order to be sure that
the switch changeover, happen at the same pressure value (five
time as minimum)

12 For Pressure Switches that the D,W. Tester oil is not suitable, the
Test Benches Instrument air or Nitrogen gas and relevant
Pressure Calibrators shall be used.
Switches pressure connection shall be done using the standard
pressure leads for
LP (up-to 7 Bar) and HP (more than 7 Bar from nitrogen bottle as
pressure source)

13 Follow step by step the similar instructions criteria on points from
7.4 to 7.9 , shall be applied considering that the Pressure Switches
shall be connected, in this case, to Test Benches Pressure
Calibrators.

14 After Setting completion, all temporary pressure and electrical
connections shall be removed, previous instrument connection
fittings restored and relevant Calibration Label applied

15 Finally a standard Calibration Sheet with all reference data
shall be issued
and stored in Instrument Workshop file as record.

Attachments

Standard Calibration Sheet for Switch calibration record.

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Job Sheet 3.2.1: Field Inspection Check of Control Valve with Electro/Pneumatic
Positioner

Learning outcomes:
3 Maintain I & C Devices
Learning Activity:
3.2 Conduct Field Inspection Check of Instrument and its Normal Function

Purpose and scope

This Job Sheet covers the maintenance inspection checks of Control Valve with
Electro/Pneumatic (I/P) Positioner and the confirmation that they are functioning in
accordance with the design.

References

 Control Valve Operation/Maintenance Manual/Datasheet

 I/P Positioner Operation/Maintenance Manual/Datasheet

Materials and Equipment

Test Equipment to be used includes:

DRUCK Loop Calibrator or Transmation Signal Generator
Standard hand tools:

 Screw drivers
 Precision Screw Drivers
 Wrench
 Portable Compressor
 Air/Filter Regulator

Responsibilities
Instructor is responsible for raising the Work Permit and that the job is performed correctly
and is aware of all hazards present, also including the recording of Maintenance details.

The Student is responsible for the execution of the work and for compliance with this Job
Sheet

Work instruction / Activity

Field Inspection Checks for Control Valves + Electro-Pneumatic Positioner
1. Obtain work permit from Supervisor

2. Obtain copies of P & ID, ILD (Instrument Loop Diagram) and Data sheets etc, as

required Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
and Control Devices July 07, 2010 1
Code No.

Job Sheet 3.2.1: Field Inspection Check of Control Valve with Electro/Pneumatic
Positioner

3. Check if v/v is direct or reverse acting.

4. Ensure with panel operator that the loop is in manual operation mode

5. Ensure panel operator applies any MOS overrides as required

6. Check Instrument tag numbers and cable numbers are correct and secure. Check for
any damage.

7. Remove I to P & Positioner covers and check for damage, dust or moisture

8. Check air supply pressure to positioner.

9. Check all Instrumentation for air leaks on connectors, regulator vents, v/v diaphragm
etc, using soap & water solution or Snoop.

10. Check the positioner feedback linkage is not loose or damaged

Open the knife switches to the v/v I to P converter according to the ILD (Instrument
Loop Diagram) for the specified loop.
11. Disconnect the input wires to the I to P in the field and connect the mA source.

12. Inject 4.0mA in to the I to P make certain that the v/v is in the fully closed position, if
direct acting or inject 20mA if reverse acting

13. The v/v should just start to open at > 4.5 mA (direct acting) or < 19.5 mA (reverse
acting)

14. Inject 4.0, 8.0, 12.0, 16.0 & 20.0 mA corresponding to 0, 25, 50, 75 & 100% of travel.
Repeat test with both rising and falling inputs, check that the v/v movement is smooth
and record input currents vs v/v position, check for any dead band or hysteresis. V/v
should move smoothly . Record all results.

15. Should the positioner require calibrating follow the procedure in the manufacturers
maintenance manual.

16. For other positioner. Zero adjustment is accomplished by loosening the lock nut and
adjusting the zero adjusting knob, this should be adjusted as indicated in Step 13.

17. Range adjustment is accomplished by loosening the lock screw on the range
adjustment arm and the turning the adjacent gear screw so that the v/v is at full stroke
at the desired maximum range point. Follow Step 14.Return to the minimum signal and
check the zero point. Repeat this step until the calibration is correct.

18. Tighten the range adjustment screw and the zero adjustment locking knob, ensuring the
flat on the zero screw is parallel with the flat on the feedback screw.

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Job Sheet 3.2.1: Field Inspection Check of Control Valve with Electro/Pneumatic
Positioner

19. For the STI type. Zero adjustment is achieved by loosening the locknut on the zero
adjustment rod and then turning the adjustment nut until the desired v/v position is
reached as in Step 13. Range adjustment is achieved by moving the runner on the
toothed sector of the range arm until the desired stroke is reached. Follow Step
14.Return to the minimum signal and check the zero point. Repeat this step until the
calibration is correct

20. Tighten the zero adjusting lock nut.
21. Check all cable glands and cable connectors are tight and shroud is in good condition
22. Apply a thin smear of silicon grease to the I to P and positioner cover seals to ensure

good protection against dust and moisture
23. Check v/v stem is not damaged or scored
24. Check v/v stem gland nuts are not loose and if possible request Operations dept put

v/v back into service, check v/v stem gland for any leaks.
25. Inform panel operator that all work in the field is completed.
26. Ensure that the work site is left tidy. Return the work permit to the Supervisor for

signing off. Report any faults found to the Supervisor to input a job request for corrective
maintenance.

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Operation Sheet 3.2.2 : How to Use Smart Field Communicator

Learning outcomes:
3. Maintain I & C Devices
Learning Activity:
3.2 Conduct Field Inspection Check of Instrument and its Normal Function
Smart Field Communicator
The Smart Field Communicator (SFC) allows you to establish communication with a Smart
Field Instrument over the existing 4-20 mA DC lines on 1:1 basis covering the 4 major Process
Variable of Flow Rate, Pressure, Temperature & Level.

SFC Connection
The Illustration shows how to connect an SFC to the transmitter.

Setting Tag Number and Checking Specifications
This procedure starts communications between this transmitter and the SFC:

Step Description SFC Screen
1 Press the ALPHA, URV, MENU ITEM and 6 keys in that
DSTJ TAG NO.
order. LIN DP FIT

2 Press the ALPHA and +/- keys in that order. DSTJ TAG NO.
LIN DP FIT-

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Operation Sheet 3.2.2 : How to Use Smart Field Communicator DSTJ TAG NO.
3 Press the 1, 2, 3 and 4 keys in that order LIN DP FIT-
1234
4 Press the Enter (Yes) key
Tag No. FIT-1234 is set. DSTJ TAG NO.
WORKING…
DSTJ TAG NO.
LIN DP FIT-
1234

Checking Output Format
Check the output format (linear/square root) of the transmitter, using this procedure.

Step Description SFC Screen

1 Press the CONF key DSTJ CONFIG
CONFORM?

2 Press the ENTER (Yes) key. Square root
output
CONFORM
SQUARE
ROOT
Linear Output
CONFORM
LINEAR

3 Press the CLR (No) key twice DSTJ FIT-1234
READY…

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Operation Sheet 3.2.2 : How to Use Smart Field Communicator

.

Checking Engineering Unit of Measured Pressure
Check the engineering unit of measured pressure, using this procedure. Here it is assumed
that (kPa) is selected.

Step Description SFC Screen

1 Press the UNITS key. UNIT FIT-1234
kPa

Checking Low and High Limits of Setting Range
Check the low and high limits of the setting range, using this procedure.
It is assumed that the following values are set :
-Lower Limit (LRV): 0.0000 kPa
-Upper Limit (URV): 50 kPa

Step Description SFC Screen
1 Press the LRV (0%) key.
LRV FIT-1234
2 Press the URV (100%) key. 0.0000 kPa

URV FIT-1234
50.00 kPa

Calibration SFC Screen
Step Description

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Operation Sheet 3.2.2 : How to Use Smart Field Communicator

1 Press the SHIFT and OUTPUT (Input) keys in that order Input
0.0000 kPa

2 Press Correct Zero Input?
3 Press Enter (Yes) Are You Sure?
4 Press Enter (Yes) Input Zeroed

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Job Sheet 3.2.3: Field Inspection Check of Smart D/P Transmitter (Wet Leg)

Learning outcomes:
3 Maintain I & C Devices
Learning Activity:
3.2 Conduct Field Inspection Check of Instrument and its Normal Function

Purpose and scope

This Job Sheet covers the maintenance inspection checks of Smart D/P Transmitter and
the confirmation that they are functioning in accordance with the design.

References

 Smart D/P Transmitter Operation/Maintenance Manual/Datasheet

Materials and Equipment

Test Equipment to be used includes:

Digital or Analog Multimeter
Pressure Calibrator
SFC/HART Communicator

Standard hand tools:
 Screw drivers
 Precision Screw Drivers
 Wrench
 Portable Compressor
 Air Filter/Regulator

Responsibilities
Instructor is responsible for raising the Work Permit and that the job is performed correctly
and is aware of all hazards present, also including the recording of Maintenance details.

The Student is responsible for the execution of the work and for compliance with this Job
Sheet

Work instruction / Activity

Field Inspection Checks for SMART D/P Transmitters (Wet Leg)
1. Obtain work permit from Supervisor
2. Obtain copies of ILD (Instrument Loop Diagram), Data sheets, JB details as necessary

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Job Sheet 3.2.3: Field Inspection Check of Smart D/P Transmitter (Wet Leg)

3. Ensure with panel operator that the loop is in manual operation mode ( if the loop

is a control function )

4. Ensure panel operator applies any MOS overrides as required

5. Check Instrument tag number and cable number is correct and firmly fixed. Check for

any damage. Check with Supervisor, data sheet of Level Transmitter

6. Remove Transmitter cover and check for damage, dust or moisture.

7. Check for correct supply voltage at transmitter.

8. Connect Hart/Smart communicator to the loop, record Transmitter parameters

9. Simultaneously close Hi & Lo root isolation v/v tapping points

10. Open the vent v/v on the Lo side of the monoblock and drain off any liquids into a

container. In case the drain is plugged, ensure it is unplugged before opening the vent

v/v.

11. Open the vent v/v on the seal pot attached to the high tapping point

12. Record the readout on the Smart/Hart communicator. If the readout of the PV is the
same as the LRV ( + or – 0.5% ) and the AO = 4.0 mA, proceed to step 16. If not

proceed to the next step.

13. Connect the hand held pump containing the liquid to be injected to the outlet of the

NRV(non-return valve) attached to the HP side on the Transmitter body.

14. Pump the liquid until it comes out from the vent on the seal pot attached to the Hi

tapping point. Continue pumping until sure air or gas is not trapped in the wet leg.

Collect liquid in a container for disposal.

15. Monitor the readout on the Smart/Hart communicator. Stop filling when the analogue

O/P stabilizes at 4.0 mA

16. Disconnect the pump and plug the inlet to the NRV(non-return valve) attached to the

high side of the Transmitter body.

17. Close the vent v/v at the Lo pressure side of the Transmitter body.

18. Close the vent v/v on the seal pot attached to the Hi & Lo tapping. Report any leakage.

19. Simultaneously open Hi & Lo root isolation v/v tapping points

20. Crack open the vent v/v on the Lo side of the Transmitter and flush out the impulse line,

then close the vent v/v. Report any leaks on manifold or seal pot.

21. Monitor PV, AO & % range using the Hart/Smart communicator.

22. Verify that the indication in the control room, and the HART/SMART communicator both

indicate the same value.

23. When satisfied with the level loop calibration, disconnect the Smart/Hart communicator

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Job Sheet 3.2.3: Field Inspection Check of Smart D/P Transmitter (Wet Leg)

24. Check all cable glands and cable connectors are tight and shroud is in good condition
25. For equipment enclosure apply a thin smear of silicon grease to the transmitter seals

and the junction box door seal to ensure good protection against dust and moisture
26. Report any problem found for removal of Transmitter to W/Shop for calibration.
27. Inform panel operator that all work in the field is completed.
28. Ensure that the work site is left tidy; return the work permit to supervisor for sign off.

Code No. Maintain and Repair Instrumentation Date: Developed Date: Revised Page #
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and Control Devices July 07, 2010

Information Sheet 4.1.1: Types of Repair and Repair Techniques

Learning outcomes:
4 Repair I & C Devices
Learning Activity:

4.1 Identify Different Types of Repair and Repair Techniques

Repair Cycle
If an instrument fails or is in danger of failing, the availability of the instrument will be affected. In
principle, there will be two ways of repairing the instrument during operation or during downtime.
Emergency repairs and overhauls constitute special repair categories. Overhauls are repairs which take
place during downtime. Repairs during operation can be necessary for reasons of safety or to ensure
the continuity of the production process. Which repair technique to use will depend on the situation.
Usually, repairs will take place during downtime, with repair of the instrument or of certain parts carried
out either on the spot or under conditioned circumstances, such as in a workshop. Essential
maintenance activities during repairs are disassembly and assembly of certain parts or of the entire
instrument. A key role is played by the auxiliary tools that support these activities. We will outline the
most important phases: disassembly, repair, and assembly, and briefly discuss some of the most
important tools. The following illustration shows a diagrammatic representation of the repair cycle.

Operational Status

Instrument Instrument in
Failed Operation

Take the Tools and Putting the
Instrument Out Equipment Instrument into
of Operation Operation

Testing of
Instruments

Disassembly of Assembly of
Instrument Instrument

Repair or
Replace
Instrument

Figure 4.1.1 Diagrammatic Representation of Repair Cycle

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Information Sheet 4.1.1: Types of Repair and Repair Techniques

Taking Out of Operation

Taking an instrument out of operation for repairs is preceded by the necessary preparations,
the nature of which will depend on the situation. They will generally include planning and work
planning activities. Repairs should be based on a good repair plan.

Disassembly / Assembly

By disassembly we generally mean the removal of a machine part or of an entire instrument.
Assembly refers to a number of activities, such as mounting the various parts. Disassembly
and assembly form an important part of the repair cycle. Both activities are labour intensive
and account for a major part of the total repair time. In practice it is therefore important to aim
for efficient disassembly and assembly. This can generally be achieved by using special tools
and devices. We will give a number of examples of the use of such tools. In disassembly it is
important to remove the part in question from the plant undamaged and as quickly as feasible;
in general this will require taking apart the existing structure of the plant. Examples include
unscrewing bolt connections or breaking up welds, etc. For these purposes, special tools are
used for disassembly, hoisting and transport activities, varying from a simple pulley puller to
specially designed auxiliary structures.

Types of repair
In general, a distinction is made on the basis of the operational status. We speak of on stream
repairs and downtime repairs. Emergency repairs and overhauls form special repair
categories. Overhauls are repairs carried out during operational downtime. During operation,
emergency repairs may be required for reasons of safety or because of the production
process. We will outline the major repair techniques, in an order that differs slightly from the
classification given above.

Overhauls
By overhaul we mean a full inspection of the plant, with replacement of any worn parts. An
overhaul involves plant downtime, and in this respect overhaul resembles a major shut down.
The difference is that an overhaul will generally be more limited in scope.

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Information Sheet 4.1.1: Types of Repair and Repair Techniques

Emergency repairs
Emergency repairs may be required in a large number of situations. By emergency repairs we
mean repairs that are required to keep a plant in operation temporarily in the face of an
imminent shutdown. Emergency repairs differ from ordinary repairs in that they are generally
carried out in a race against the clock, resulting in an increased workload, and under difficult or
hazardous working conditions, etc. Here too, two situations can be distinguished: either the
repair requires a shutdown or the repair can be carried out on stream. Emergency repairs will
usually be of a temporary nature, the suppressed cause of failure will have to be permanently
removed as soon as circumstances permit.

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010

Operation Sheet 4.2.1: Disassembly/Assembly of I & C Devices-Pressure Transmitter

Learning outcomes:
4 Repair I & C Devices
Learning Activity:
4.2 Take out I & C devices out of operation and disassemble/assemble I & C devices

Maintenance procedures differ for improved and previous style transmitter housings. Verify the
specific physical characteristics of your transmitter before you begin any maintenance
procedures.

Disassembly Procedure

1. Remove the Transmitter from Service

Caution: Do not remove the instrument cover in explosive atmospheres when the circuit
is live.

NOTE
Once you have determined a transmitter to be inoperable, remove it from service.

Be aware of the following:
• Isolate and vent the process from the
transmitter before removing the transmitter
from service.
• Remove all electrical leads and conduit.
• Detach the process flange by removing the
four flange bolts and the two alignment screws
that secure it.
• Do not scratch, puncture, or depress the
isolating diaphragms.
• Clean isolating diaphragms with a soft rag
and a mild cleaning solution,
and rinse with clear water.

Code No. Maintain and Repair Instrumentation and Date: Developed Date: Revised Page #
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Control Devices July 07, 2010