Pressure Transmitter SOP [PDF]

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STANDARD OPERATING PROCEDURE TITLE PROCEDURE NO. EFFECTIVE DATE



CALIBRATION OF PT RSPL/PT/ 006 01st June 2019



1. OBJECTIVE: TO DESCRIBE THE PROCEDURE FOR THE CALIBRATION OF PRESSURE TRANSMITTER 2.



MAIN STEPS TO BE FOLLOWED :  First step to be followed is proper permit should be taken and ensure the interlocks should be by passed as well as MOS (Maintenance override to be put ON condition in DCS) for the particular tag.  Use Tool box meeting & proper PPE’S.



3.



INSTRUMENT REQUIRED:  Required tools and suitable fittings (Such as connector and union) for calibration.  24 VDC power supply  Multimeter, HART communicator, hand pump Calibrator ( Pressure range should be greater than the transmitter)



4.



PROCEDURE:



The Pressure Transmitter calibrated by competent technical person of Instrument Department under supervision of Operation person by Standard calibrator 4.0 ZERO CALIBRATION  First isolate the main process isolation valve.  De-pressurize the pressure transmitter by opening the vent valve.  Isolate the manifold valve and open the vent plug.  Fix proper instrument fitting ( for eg:1/4”npt fitting).  Connect the calibrator fitting to the transmitter.  The HART communicator cable should be placed as per transmitter wiring diagram.  Check the Zero calibration by keeping the vent valve in open condition.  If zero calibration found disturbed then zero trim can be done by using HART communicator. 4.1 SPAN CALIBRATION          



Apply pressure as per the range given in the transmitter or check with the HART communicator. Check the transmitter reading by applying pressure for 25%, 50%, 75%, and span range. After calibration checking remove the pressure calibrator from the transmitter and flush the line. So that hydraulic oil or water will not be inside the transmitter. Isolate the vent valve and open the main isolation valve. Open the manifold isolation valve slowly, if u open fast sudden pressure may damage the transmitter diaphragm. After completion of the calibration ensure the transmitter is reading showing properly. Then enter the reading in calibration  report format. Check the reading in DCS also. Close the work permit from field operator and shift Engineer.



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ABBREVIATION: PT- Pressure Transmitter



PREPARED BY:



CHECKED BY:



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