Tuesday, December 19, 2017

METHOD STATEMENT FOR INSTRUMENT CALIBRATION AND INSPECTION OF MEASURING & TESTING !!

TABLE OF CONTENTS

1.    PURPOSE

3

2.    SCOPE

3

3.    REFERENCES

3

4.    DEFINITIONS AND ABBREVIATIONS

3 - 4

5.    GENERAL

4

5.1.        PERSONNEL DUTIES AND RESPONSIBILITIES

4 - 5

5.2.        QUALIFICATIONS AND TRAININGS

5

5.3.        CALIBRATION STANDARDS AND REFERENCE MATERIALS

5 - 6

5.4.        CALIBRATION WORKSHOP AND TEST FACILITY

6

5.5.        PHYSICAL ENVIRONMENT OF CALIBRATION WORKSHOP

6

5.6.        ENVIRONMENTAL CONDITIONS

7

5.7.        CALIBRATION CERTIFICATES/REPORTS

7

5.8.        CONTROL OF NON-CONFORMING CALIBRATION WORK

7

5.9.        REFERENCE STANDARD, TEST EQUIPMENTS AND TOOLS

7 - 8

5.10.      RECEIPT, HANDLING AND STORAGE

8

6.    SAFETY REQUIREMENTS

8 - 9

7.    CALIBRATION CONSIDERATIONS

9

8.    CALIBRATION PROCEDURE

9

8.1.        TRANSMITTER CALIBRATION

9 - 10

8.2.        TEMPERATURE CALIBRATION

10 - 12

8.3.        PRESSURE CALIBRATION

13 - 15

8.4.        LEVEL CALIBRATION

15 - 17

8.5.        FLOWMETER CALIBRATION

17

8.6.        CONTROL VALVE CALIBRATION

17 - 18

9.    QUALITY ASSURANCE AND TESTING

18

10.  ATTACHMENTS

18

1.    PURPOSE

The purpose of this method statement is to provide guideline for calibration and inspection of measuring & testing shall be carried-out in a neat, efficient and skillful manner, assuring satisfactory results. The work shall be in accordance with the requirements of the project specifications, standards, and shall fulfill their true intent and meaning.


2.    SCOPE

This method statement covers the methodology for calibration and inspection of measuring & testing in Luberef Yanbu Expansion project.
These guidelines and information describes the calibration and inspection of measuring & testing techniques and different requirements to be adhered during the course of execution for calibration and inspection of measuring & testing, to get a satisfactory result and in accordance with established safety practices. It does not intend to cover all details and variations in calibration and inspection of measuring & testing nor provide for every possible, available contingency representation.


3.    REFERENCES

a)    Project Scope of Works
b)    Project Technical Specification
c)    Applicable Saudi ARAMCO standards.
d)    Issued for Construction drawings


4.    DEFINITIONS AND ABBREVIATION
a)    Calibration                   The set of operations that establish, under specified
                                    conditions, the relationship between values of quantities
                                    indicated by a measuring instrument or measuring system
                                    and the corresponding values realized by standards.
b)    Accuracy                    The difference between a measurement reading and the
                                    true value of that measurement.
c)    Error                            Offset or deviation (either positive or negative) from the
                                    correct value.
d)    UUT                            Unit Under Test – An instrument or equipment that shall be
                                    calibrated and tested to determine performance and
                                    proficiency of the unit i.e. instrument, equipment,
                                    transmitter, gauges, control valve etc.
e)    Reference Standard   A device or material used to calibrate UUT and provide
                                    traceability of measurements to international standards.
f)     TUR                            Test Uncertainty Ratio – The ratio of the uncertainty of the
                                    test item (DUT) to that of the measurement reference
                                    standard used in the calibration. Commonly acceptable
                                    TUR in International Standards is at least 1:4 ratio.
g)    Hysteresis                   The delay between the action and reaction of a measuring
                                    instrument. Hysteresis is the amount of error that results
                                    when this action occurs.
h)    Linearity                      The amount of error change throughout an instrument's
                                    measurement range. Linearity is also the amount of
                                    deviation from an instrument's ideal straight-line
                                    performance.
i)      Traceability                  The property of the result of a measurement or the value of
                                    a standard whereby it can be related to stated references,
                                    usually national or international standards, through an
                                    unbroken chain of comparisons, all having stated
                                    uncertainties.
a)    5-point calibration        In 5-point calibration , three basic steps are involved,
                                    namely: 1) zero adjustment (LRV), 2) linearity adjustment
                                    (25%, 50%, & 75%), and 3) span adjustment (URV)
b)    SAES                          Saudi Aramco Engineering Standard
c)    SATIP                         Saudi Aramco Technical Inspection Procedure
d)    SAIC                           Saudi Aramco Inspection Checklist
e)    NEC                            National Electrical Code
f)     IEC                              International Electro-Technical Commission
g)    RFI                              Request for Inspection
h)    MRR                           Material Receiving Report
i)      ITP                              Inspection and Test Plan
j)      COMPANY                 Luberef or its designated Representative
k)    CONTRACTOR         Samsung Engineering Const. Ltd.
l)      SUBCONTRACTOR  Any Individual or Corporation under contract to the
                                    CONTRACTOR who perform the entire and/or some
portion of the work or services on a project which the CONTRACTOR has agreed upon.


5.    GENERAL

5.1.        PERSONNEL, DUTIES AND RESPONSIBILITIES
a)    Instrumentation Manager
i)      Manager will be coordinating with concerned personnel, plan the daily work schedule and enforce strict adherence to all project requirements.

b)    Instrument Supervisor
ii)     Supervisor is responsible and ensuring that the works are carried out accordance to the COMPANY requirements, scope of work, and approved Method Statement.
iii)    Monitor the progress of work in relation with the work program and to report to the Manager.
iv)   Coordinate with Safety Officer and to ensure that the works are carried out in safe practicing methods.

c)    Calibration Technician
i)      He shall be approved to perform calibration by the COMPANY.
ii)     He shall demonstrate a technical competence, education, skills, training, and practical experience. Records are to be available in demonstrating his qualifications.
iii)    He is responsible to conduct calibration and testing of equipment as per approved procedure and reference standard.
iv)   He shall complete required calibration and testing in accordance with documented requirement, record and report on the findings.

d)    Quality Control Manager
i)      Responsible for the implementation of all required quality control activities such as test and inspection for this particular job and keeps record of its necessary documentation.

e)    Quality Control Inspector
i)      Inspect the work to comply according to Company standards.
ii)     He shall be responsible for conducting surveillance and inspection duties during test activities and ensuring quality compliance.
iii)    He shall review all relevant documents and test reports.

f)     Safety Supervisor
i)      Make sure that all safety measures are complied before starting the work.
ii)     Provide safety instructions to the workers.
iii)    Ensure the implementation of all the safety measures in accordance with the HSE plan and everybody aware of it, for its proper implementation.
iv)   Ensure all the implemented safety measures are adequate to maintain the safe working on the site.
v)    Inspect all the site activities and train the persons to prevent accidents and its proper reporting to the project manager and the client.

5.2.        QUALIFICATIONS AND TRAININGS
a)    Supervisors & Inspectors must be eligible and competent for the job.
b)    Technician must able to understand his work and require trade certificates if necessary.
c)    Conduct trainings regularly to maintained safety and good workmanship.

5.3.        CALIBRATION STANDARDS AND REFERENCE MATERIALS
a)    The reference standards used in calibration workshop are to be calibrated by a calibration service provider that the traceability of the calibration(s) is traceable to national/international metrology institution.
b)    Equipment (Reference standards) - Calibration workshop must have all the calibration standards and reference materials available for the calibrations to be performed.
c)    Calibration of Reference Standards - The calibration standards supporting calibration systems are to be calibrated on a regular schedule to maintain precision and traceability as per manufacturer’s recommendation. Records are to be available to verify the drift of reference standards and demonstrate compliance with this requirement.
d)    The calibration certificate for reference standards and related records must provide evidence that the calibration service provider utilized calibration standards that are traceable to national/international standards.
e)    The calibration standards shall be maintained in accordance with the following:
1.    A unique identification number such as tag number, the manufacturer’s name, an assigned identification number or model and serial number.
2.    The manufacturer’s instructions or operating manual.
3.    Calibration records - including adjustments made, certificates, next calibration date and calibration dates.
4.    Calibration records and procedures shall clearly specify when the calibration of the instrument expires.
f.     Measurement Traceability - All calibration equipment is to be calibrated using Measurement Standards traceable to a national metrological institute e.g. NIST or a government-sponsored / approved national metrology institute, either directly, or through a regional group. Calibration equipment is deemed traceable through an accredited calibration service provider.
g.    Reference materials i.e. metric to english conversion table, RTD conversion table, thermocouple conversion table etc. must be available at all time and easy to locate in calibration workshop.

5.4.        CALIBRATION WORKSHOP AND TEST FACILITY
A location where the work shall be carry out, a temporary portable laboratory facility prepared specifically for the purpose of completing calibration and testing at project premises or site location.

5.5.        PHYSICAL ENVIRONMENT OF CALIBRATION WORKSHOP
a)    Calibration workshop must maintain appropriate environmental conditions as specified by documented calibration procedures or methods being applied to assure the correct performance of calibrations. This requirement includes control and monitoring of parameters that may affect the quality of calibrations including humidity, temperature, vibration, etc.
b)    Other relevant conditions that may be a source of error such as dust, electromagnetic disturbances, radiation, electrical supply, sound and vibration levels are to be controlled and monitored as appropriate to the technical activities concerned. Calibrations are to be halted when the environmental conditions may jeopardize the results of the calibrations. Corrective action is to be taken before proceeding with calibrations.
c)    There shall be effective separation between neighboring areas in which there are incompatible activities. e.g. Construction works, Vibration from heavy equipment that may affect a calibration process. Distance or appropriate barriers must separate these calibration activities.


5.6.        ENVIRONMENTAL CONDITIONS
25 °C ±3 °C, 40% to 50% RH

5.7.        CALIBRATION CERTIFICATES/REPORTS
Calibration certificates and/or reports provided by calibration workshop shall contain the following information:
a)    Company logo of Luberef, Samsung and SUBCONTRACTOR.
b)    Location where the calibrations were carried-out.
c)    Unique identification of the calibration certificate.  Each page of supporting data requires an identification to ensure that the page is recognized as a part of the calibration certificate package.
d)    An unambiguous identification of the item(s) tested or calibrated e.i. Tag Number, Nameplate Data (Manufacturer, Model Number, Serial Number etc).
e)    Reference to the sampling plan and procedures used by the workshop or other bodies if these are relevant to the validity or application of the results;
f)     Reference Standards data e.i. Tag Number, Nameplate data, Calibration due date etc
g)    Calibration Range and Calibration Tolerance
h)    The calibration results (as-found and as-left data) with the units of measurement, where appropriate,
i)      Calibration date and Due date
j)      The name(s), functions(s) and signature(s) or equivalent identification of person(s) authorizing the calibration certificate;
k)    The conditions (e.i. environmental temperature and humidity) under which the calibrations were made that have an influence on the measurement results;
l)      Evidence that the measurements are traceable (to national standards)
m)  Comments

5.8.        CONTROL OF NON-CONFORMING CALIBRATION WORK
a)    Records to be maintain of every event where non-conforming calibration work is found.
b)    Where non-conforming conditions occur, Calibration personnel is to determine if there are defects in the processes used or data developed.
c)    If the cause of the non-conforming work is found to affect calibration or testing data. CONTRACTOR shall be informed for immediate resolution if the “as-found” data was not within the acceptable tolerance.

5.9.        REFERENCE STANDARD, TEST EQUIPMENTS AND TOOLS
a)    Pressure source of pressure such as a hand pump or regulated pressure source (Compressor-oil free type), Nitrogen Gas
b)    Precision gauge or digital test standard
c)    Comparator
d)    Manometer or dead weight tester
e)    Temperature dry-well calibrator
f)     Thermometer Simulator
g)    Decade Resistance Box
h)    Temperature reference standard
i)      6.5 Digital Multimeter
j)      Handheld Multimeter (Digital and Analog type)
k)    HART Communicator
l)      Milli-Ampere Simulator
m)  Automatic Voltage Regulator
n)    DC Power Supply
o)    Calculator
p)    Hand Tools
a)    Other appropriate standard equipment required to be used during calibration
q)    Appropriate safety equipment

5.10.      RECEIPT, HANDLING AND STORAGE
a)    After receiving the UUT. It shall be calibrated and inspected to ensure that it functions correctly, establish the reliability of the UUT and is in fit condition to be installed in projects site. All calibrated instrument must be signed off by concerned parties.
b)    All UUT for calibration & testing shall be checked on receipt for damage and deficiency, any item found to be defective or incomplete at this stage, or during subsequent calibration, or testing shall be reported to the CONTRACTOR and their disposition agreed before any further action.
c)    All UUT calibration certified or tested condition must be handled with care and protected from any impact, vibration or any magnetic disturbance, dust free environment, away from direct sunlight and sudden change in temperature that could adversely affect the accuracy of the instrument.


6.    SAFETY REQUIREMENTS
a)    Conformity and execution in accordance with field Safety Management Plan.
b)    Safety management during work (Worker Personnel Protective Equipment and temporary safety structure establishment / operation).
c)    Regarding to safety all relevant JHA (Job Hazard Analysis) will be submitted separately.
d)    Toolbox talk shall be conducted daily prior to work start Permit to Work (PTW) must be obtained and available at the work location.
e)    Safety Supervisor / Officer to ensure working area shall be safe and in good condition.
f)     Safety Supervisor / Officer shall carry out the safety site inspections to ensure that safety requirements laid in the safe work plan are being followed during and after the work.
g)    CONTRACTOR/SUBCONTRACTOR shall provide safety equipments as necessary according to an evaluation of expected needs during the work. This applies to temporary fire extinguishers first aid equipments, stretcher, etc.
h)    Authorized personnel shall inspect all equipments and electrical tools prior to commence any Work and shall be inspected & tag by safety personnel to ensure their safe worthiness at work. The inspection reports shall be kept for record.
i)      Hazardous substance likely to be used during the work e.g. Paint, Lubricant, etc. shall be used per established safety work practice and in accordance with the information from a Material Safety Data Sheet (MSDS).
j)      Calibration personnel shall ensure that before leaving their working places, it must be clean, tidy and free from rubbish.


7.    CALIBRATION CONSIDERATIONS

a)    Correct reference standard equipment used during calibration and shall meet the required criteria of TUR per available national/international standards.
b)    Before any UUT is calibrated, the UUT must stabilize (warm-up) according to manufacturer’s instructions.
c)    Bench test for calibration is performed at the workshop.
d)    Since precise test for the instrument or equipment has been performed at the manufacturing shop, the bench test inspects more on the zero point calibration and span rather than precise calibration.
e)    Check the air (with clean air without oil) and power utilities for use before testing.
f)     Transmitter (UUT) shall be checked both the milli-ampere value and specified process variable.
g)    Tolerance shall be checked as per Datasheet of the instrument, gauges, control valve etc.
h)    For UUT that has completed testing shall be clean by blowing with clean air without oil, and seal the joints and equipment inlets to prevent moisture and dust from entering.
i)      Install the testing instrument on rigid points free from vibrations.
j)      If necessary, UUT power source shall be provided if separate power source is required. Make sure that the method of wiring connection is correct before proceeding the calibration to avoid before instrument or equipment damages.
k)    Calibration label shall be affixed in every UUT to identify a successful calibration, it specified the tag number, date of calibration, and initial/sign of calibration technician.
l)      All calibrated UUT shall be sealed with tamper-resistant seals to preclude any tampering with calibration controls or adjustments.


8.    CALIBRATION PROCEDURE

8.1.        TRANSMITTER CALIBRATION
8.1.1.    HART FUNCTION
1.    The standard test equipment used is a Communicator (HART).
2.    Hook-up the transmitter (UUT) to reference standard (communicator).
3.    Simulate milli-ampere signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT ranges both the upscale and downscale directions.
Note: For UUT with square root capability make sure to simulate a correct required current value.
4.    Record the “as-found” value of reference standard and UUT.
5.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
6.    If adjustment is required, perform zero and span adjustment per the manufacturer’s procedures.
7.    Or use the general instructions of Zero and Span point adjustment, as follows:
a.    Using the Zero-and-Span adjustment screw
b.    Pressing the Zero and Span push button adjustment
c.    Others require the use of handheld interface or communicator to convey specific information to the UUT.
8.    Because some zero and span adjustment interact, it is important to recheck the zero and span until no further adjustment is required.
9.    Once no further adjustment is required, repeat the 5-point test, verify that it is within tolerance over the defining specification and record “as-left” values.

8.1.2.    FIELDBUS FUNCTION
1.    Normally, workshop calibration for Fieldbus function is not essential but data record is required.
2.    Ensure that the UUT and its accessories are in good conditions and no physical damage on the body.
3.    Record data such Tag number, Maker, model number, etc on the calibration data sheet.
4.    The UUT shall be tested as part of loop test.
5.    Lest that the calibration of Fieldbus function is recommended by COMPANY. Make sure that the change of device parameters during calibration shall be put the control loop in Manual/Out of Service before applying any changes. Verify the output and device parameters are correct during the normalization state of the transmitter. Failure to do so may result on device damage.
6.    Calibration of Fieldbus devices is similar with calibration of HART function.
7.    Follow the calibration procedure of HART function.

8.2.        TEMPERATURE CALIBRATION
a)    CALIBRATION OF A DIAL THERMOMETER
1.    The standard test equipment use is a temperature dry-well calibrator, and temperature reference standard.
2.    Set the temperature of dry-well calibrator and wait that the temperature value to stabilize.
3.    The dial thermometer (UUT) sensor and reference standard thermometer shall be immersed in the temperature dry-well calibrator. Consider to correctly depth the immersion length of each thermometer.
4.    Simulate temperature signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT ranges both the upscale and downscale directions.
5.    Record the temperature “as-found” value of Reference Standard and UUT.
6.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
7.    Some thermometer (UUT) are not adjustable, in which case the UUT status shall be informed to CONTRACTOR for immediate resolution if the “as-found” data was not within the acceptable tolerance.
8.    In case the UUT can be adjusted, adjust the UUT based on the average error such that all readings are as close as possible.
9.    Once no further adjustment is required, repeat the 5-point test, verify that it is within tolerance over the defining specification and record “as-left” values.

b)    CALIBRATION OF TEMPERATURE SENSOR (RTD AND TC TYPE)
1.    The standard test equipment use is temperature dry-well calibrator, and temperature indicator reference standard.
2.    Set the temperature of dry-well calibrator and wait that the temperature value to stabilize.
3.    Hook-up the temperature sensor (UUT) in temperature indicator reference standard. Make sure that the temperature type is matching with type settings of reference standard.
4.    Immersed the UUT in the temperature dry-well calibrator. Consider to correctly depth the immersion length of sensor.
5.    Simulate temperature signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT ranges in upscale directions (linearity check).
6.    Evaluate the error against the acceptable tolerance to verify that it is within tolerance over the defining specification of the UUT
7.    Temperature sensors (UUT) are not adjustable, in which case the UUT status shall be informed to CONTRACTOR for immediate resolution if the “as-found” data was not within the acceptable tolerance.
8.    This will complete the calibration of temperature sensor.

c)    CALIBRATION OF RTD TYPE TEMPERATURE TRANSMITTER
1.    The standard test equipment use is a decade box or Resistance Temperature Detector (RTD) simulator.
2.    Commonly used RTD type temperature sensor in industrial-grade RTD is PT100, which is a 100 ohm at 0°C, platinum, with coefficient values of 0.00385 ohm/ohm/°C alpha.
3.    Hook-up the RTD type temperature transmitter (UUT) to reference standard test equipment (Decade box or RTD simulator).
Note: When using Decade Resistance Box as standard it will introduce error to wiring connection. Make sure that the test lead used of 3-wire system is the same size and length. For 2-wire system, make sure to eliminate error associated to the test lead resistance.
4.    Simulate temperature/resistance signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT ranges both the upscale and downscale directions.
5.    In case, a decade box has been-used as standard equipment. Record the resistance and temperature “as-found” values and check the correct corresponding temperature values per Temperature conversion table of RTD -PT100 type temperature.
6.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
7.    If adjustment is required, perform zero and span adjustment per the manufacturer’s procedures.
8.    Or use the general instructions of Zero and Span point adjustment, as follows:
a.    Using the Zero-and-Span adjustment screw
b.    Pressing the Zero and Span push button adjustment
c.    Others require the use of handheld interface or communicator to convey specific information to the UUT.
9.    Because some zero and span adjustment interact, it is important to recheck the zero and span until no further adjustment is required.
10.  Once no further adjustment is required, repeat the 5-point test, verify that it is within tolerance over the defining specification and record “as-left” values.

d)    CALIBRATION OF THERMOCOUPLE (TC) TYPE TEMPERATURE TRANSMITTER
1.    The standard test equipment use is a thermocouple simulator of correct type.
2.    Connect the TC type temperature transmitter (UUT) to reference standard test equipment. Make sure that the UUT typesetting is matching with reference standard thermocouple simulator.
3.    Simulate temperature signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT range in both the upscale and downscale directions.
4.    Repeat procedure for remaining temperature type of the UUT.
5.    Once the “as-found” data has been recorded evaluate the error against the acceptable tolerance to determine if adjustment is required.
6.    If adjustment is required, perform zero and span adjustment per the manufacturer’s procedures.
7.    Or use the general instructions of Zero and Span point adjustment, as follows:
a.    Using the Zero-and-Span adjustment screw
b.    Pressing the Zero and Span push button adjustment
c.    Others require the use of handheld interface or communicator to convey specific information to the UUT.
8.    Because some zero and span adjustment interact, it is important to recheck the zero and span until no further adjustment is required.
9.    Once no further adjustment is required, repeat the 5-point test, verify that it is within tolerance over the defining specification and record “as-left” values.



8.3.        PRESSURE CALIBRATION
a)    CALIBRATION OF PRESSURE GAUGES
1.    Pressure gauges (UUT) shall be calibrated using a source of pressure such as a hand pump or regulated pressure source, precision gauge or digital test standard with the correct module, Comparator, manometer or dead weight tester
2.    Use a Tee to connect the input reference standard to the pressure source and the UUT. Mounting of UUT during calibration to be followed as per site installation. In case, you are unsure for mounting direction, vertical position is the prepared method.
3.    Simulate a 50% pressure and locked-in signal pressure-check system for leaks, then reset to zero.
4.    For any mechanical instrument, it is important to determine whether hysteresis error is present in the UUT. This means you will begin your upscale check from 0% and approach the first test point, 10% from below. Approach each increasing test point from below and do not overshoot.
5.    Similarly, start the downscale check by increasing the input to 100%, then approach 90% from above.
6.    Once the “as-found” data has been recorded evaluate the error against the acceptable tolerance to determine if adjustment is required.
7.    If the result is outside the allowable tolerance, determine the type of error present (linearity, zero, span, and hysteresis), and adjust per the manufacturer’s instructions or use the general instructions, as applicable, that follow.
a.    For motion balance instruments, linearity adjustment shall be done first. The movement of the elastic element in a pressure gauge causes a proportional movement in the linkage.
b.    On a properly calibrated gauge, the linkage angle will be exactly 90 degree when the input to the gauge is 50% of total range. Therefore, apply 50% input and       use a template to check the 90 degree angle.
c.    With linearity adjusted, position the pointer so the gauge reads mid-scale. You may need to remove the pointer and reposition it on the shaft. If removing the pointer is necessary, be sure to use the proper tool. Adjust the pressure input to 10% and adjust the zero so the gauge reading equals the applied input.
d.    Now correct the span error. Increase the input pressure to 90% and adjust the gauge to read the input value. For span adjustment, loosen the crews and rotate the entire adjustment mechanism.
e.    Repeat the zero and span adjustment until the reading of 10% and 90% are accurate. Zero and span interact in the mechanical device, so rechecking them is necessary. When zero and span require no further adjustments, recheck the linearity to make sure it is still properly adjusted.
f.     There is no adjustment for hysteresis.
8.    After adjusting linearity, zero and span, perform another full scale check, verify that it is within tolerance over the defining specification and record “as-left” values.

b)    CALIBRATION OF PRESSURE TRANSMITTER
1.    Connect the pressure transmitter (UUT) to applicable standards.
2.    Simulate pressure signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT ranges both the upscale and downscale directions.
3.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
4.    If adjustment is required, perform zero and span adjustment per the manufacturer’s procedures.
5.    Or use the general instructions of Zero and Span point adjustment, as follows:
a.    Using the Zero-and-Span adjustment screw
b.    Pressing the Zero and Span push button adjustment
c.    Others require the use of handheld interface or communicator to convey specific information to the UUT.
6.    Because some zero and span adjustment interact, it is important to recheck the zero and span until no further adjustment is required.
7.    Once no further adjustment is required, repeat the 5-point test, verify that it is within tolerance over the defining specification and record “as-left” values.

c)    PRESSURE SWITCHES CALIBRATION
1.    A pressure switch (UUT) is a device that senses pressure and changes state at the programmed or adjusted set-point.
2.    Connect variable pressure source to reference test gauge and Hi-side pressure switch (UUT) port.
3.    Connect a Multimeter set to continuity range across Common “C” and Normally Open “NO” switching element contacts. The meter should read an open circuit.
4.    Increase the pressure to the set-point of the pressure switch (UUT) until the contacts change over. The meter should read “short circuit”. Record the “as-found” pressure value for a rising pressure.
5.    Increase the pressure to the switch maximum rating. Slowly reduce the pressure to the UUT until the switch changes over from closed to normally open position. Record the “as-found” pressure value for a falling pressure.
6.    From the two readings been taken, the pressure difference between the rising and falling pressure settings. This is called “dead-band” of the switch.
7.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
8.    If adjustment is required, follow the manufacturer’s procedures for adjustment of set-point.
9.    Once no further adjustment is required, repeat the procedure, verify that it is within tolerance over the defining specification and record “as-left” values.

d)    PRESSURE METERS
(Displacement type Pressure meter)
1.    Workshop calibration is not essential but data record is required.
2.    Ensure that the UUT and its accessories are in good conditions and no physical damage on the body.
3.    Record data such Tag number, Maker, model number, etc on the calibration data sheet.
4.    The UUT shall be tested as part of loop test.

8.4.        LEVEL CALIBRATION

8.4.1.    SPECIAL CONSIDERATIONS WITH LEVEL CALIBRATION
a)    SUPPRESSED/ELEVATED ZERO
1.    If the D/P cell is not located at an elevation that corresponds to 0% level in the tank, it must be calibrated to account for the difference in elevation. This calibration adjustment is called zero elevation when the cell is located above the lower tap; it is called zero suppression when the cell is located below lower tap.
2.    To calculate the amount of elevation or suppression, the distance between the zero reference level and the high pressure port of the D/P cell must be accurately measured.

b)    SPECIFIC GRAVITY
1.    During calibration of DP level devices, it is important to consider the specific gravity of the process material to avoid error during the calibration.
2.    To calibrate a D/P transmitter for a sensor monitoring. The nominal test point for input pressure must be multiplied with equivalent process fluid specific gravity

c)    DRY AND WET LEGS
1.    For differential pressure measurements, the pressure of the vapor in pressurized vessels is connected to the low pressure side of the D/P cell. When process vapor are non-condensing, non-corrosive, non-plugging, the leg external to the vessel that is connected to the D/P cell is a dry leg. If any condensate accumulates in the leg, significant error would result in the level indication. This would reduce the D/P sensed and result in a level indication or output that is lower than the actual level. If the process vapors condense, the reference leg can be filled to form a wet leg. The specific gravity and height of the reference column must be accurately determined and accounted for in any calibration of the D/P cell.


8.4.2.    LEVEL CALIBRATION

a)    CALIBRATION OF DIFFERENTIAL PRESSURE (D/P) LEVEL TRANSMITTER
1.    Connect the D/P Transmitter (UUT) to applicable standards.
2.    Calibration of UUT is similar to calibrating a pressure transmitter.
3.    Measured pressure is applied to the high pressure port of the D/P cell, and low pressure side is vented to atmosphere.
4.    Be sure to remove any caps, and the low pressure side is vented to atmosphere. Be sure to remove any caps, cleanliness plugs, or obstructions from the low pressure port.
5.    Simulate pressure signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT ranges both the upscale and downscale directions.
6.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
7.    If adjustment is required, perform zero and span adjustment per the manufacturer’s procedures.
8.    Or use the general instructions of Zero and Span point adjustment, as follows:
a.    Using the Zero-and-Span adjustment screw
b.    Pressing the Zero and Span push button adjustment
c.    Others require the use of handheld interface or communicator to convey specific information to the UUT.
9.    Because some zero and span adjustment interact, it is important to recheck the zero and span until no further adjustment is required.
10.  Once no further adjustments are required, repeat the 5-point test and verify that it is within specification over the defined operating range. Record “as-left” values in calibration data sheet.

b)    CALIBRATION OF DISPLACEMENT TYPE LEVEL GAUGE
1.    Establish an independent method for determining the actual level in the tank
2.    Fill the level gauge chamber (UUT) with clean water using plastic tubes at the bottom of the drain, similar to the gauge glass.
3.    Simulate level that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the readings “as-found” at each test point.
4.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
5.    Some level gauge are not adjustable, in which case the gauge status shall be informed to CONTRACTOR for immediate resolution if the “as-found” data was not within the acceptable tolerance.
6.    In case the UUT can be adjusted, adjust the UUT as per manufacturer’s recommendation.
7.    Once no further adjustments are required, repeat the 5-point test and record “as-left” values.
c)    LIQUID LEVEL METERS
(Displacement, Ultrasonic, Capacitance and Diaphragm type Level meter)
5.    Workshop calibration is not essential but data record is required.
6.    Ensure that the UUT and its accessories are in good conditions and no physical damage on the body.
7.    Record data such Tag number, Maker, model number, etc on the calibration data sheet.
8.    The UUT shall be tested as part of loop test.

8.5.        FLOWMETER CALIBRATION

a)    DIFFERENTIAL PRESSURE FLOWMETERS
1.    Calibration of D/P Flowmeter is similar with a D/P pressure transmitter.
2.    Follow the calibration procedure of D/P pressure transmitter.

b)    FLOWMETER
(Turbine and Static Capacity, Ultrasonic, Magnetic, Vortex Shedding, Rotameter, Coriolis and Diaphragm type Flow meter)
1.    Workshop calibration is not essential but data record is required.
2.    Ensure that the UUT and its accessories are in good conditions and no physical damage on the body.
3.    Record data such Tag number, Maker, model number, etc on the calibration data sheet.
4.    The UUT shall be tested as part of loop test.

8.6.        CONTROL VALVE (FINAL CONTROL DEVICE) CALIBRATION
1.    The control valve (UUT) is set with chain Block or Pulley, to the identical condition or actual installation.
2.    Control valves (UUT) operated by diaphragm or piston are operated with air (oil free) or using a nitrogen by using pressure regulator, test gauge, and direct current supply device, milli-ampere simulator.
3.    Inspect accessory material operations such as hand wheel, amplifier, relay, and lockup valve.
4.    Set-up the UUT and makes sure that it is secure.
5.    Simulate signal that corresponds to 0%, 25%, 50%, 75% and 100% (5-point test) of the UUT measurement range and record the “as-found” value. Check the UUT range in both the upscale and downscale directions.
6.    Test the following performance of control valve (UUT) as follows:
a.    Valve action
b.    Air and power supply fail action
c.    Stroke Test
d.    Stroking time
e.    Limit Switch function
f.     Other function test that is required for specific control valve.
7.    Evaluate the error against the acceptable tolerance to determine if adjustment is required.
8.    If necessary, adjust the UUT in accordance with the manufacturer’s instruction.
9.    Once no further adjustments are required, repeat the 5-point test and record “as-left” values.


9.    QUALITY ASSURANCE AND TESTING
a)    A Quality Assurance System shall be operated conforming to related Standards, Specifications and Procedures.
b)    Controls and checks shall be established and documented Manufacturer’s recommendation for products and materials that used needs special attention.
c)    Quality Control, Inspection and Testing are covered under the Quality Control Procedure.
d)    Inspections and tests shall be carried out in accordance with the approved ITP and procedures and in accordance with the project specification.
e)    Request for Inspection (RFI) and material testing to be raised as per procedures.
f)     The inspection result shall be documented on the related reports/checklist.


10.  ATTACHMENTS

a)    Job Safety Analysis (JSA)

No comments:

Post a Comment