Calibration and Validation of Pressure Relief Valve

This article is about how to perform calibration of Pressure Relief Valve or validation and setting the pressure of relief valves.

Calibration of Pressure Relief Valve

Prior to testing the relief valve shall be subject to thorough visual inspection for any obvious surface
The valve shall be mounted on the rig.
Test gauges for checking the set shall bear± 3 %.
The testing pressure shall be increased gradually until the valve lifts at the cold set pressure specified on the data sheet.
After successful testing of the cold set pressure, the valve shall be subject to a seat tightness test.
The applied pressure of the testing medium shall increase gradually to 90% of the “COLD SET PRESSURE”.
The test result shall be recorded.
Acceptance criteria for a valve with metal sat the leakage rate in bubbles per minute shall not exceed in 50 % of the appropriate value in API standard Table 1. For soft seated valve there shall be no leakage for 1 minute (0 bubbles per minute).
All tested PRVs should be mechanically sealed immediately after testing has been completed with seal wire lock punch.
Each PRVs shall assigned with serial number for tracking and record (SAEP-318).
Each PRESSURE RELIEF VALVE shall have a history log file in Calibration Shop. This file should include the PRESSURE RELIEF VALVE Engineering date, and components (i.e. spring), changes and
Test PRESSURE RELIEF VALVE used for PRESSURE TESTING shall be identified with corrosion resistant metal tag as description, and stamped as follows:

“TEST PRESSURE RELIEF VALVE”

Spring Number————————-

Set Pressure———————————

Test Date——————————————

Gently operate the pnuematic pump comparator to achieve the desired set pressure.
Once reach the desired set pressure, the PRESSURE RELIEF VALVE should open or The PRESSURE RELIEF VALVE shall open or pop ONLY at the desired set pressure.
In case the PRV does not open or pop on the desired set pressure ( more or less then the desired pressure), depressurized the pneumatic pump comparator and carefully remove the PRESSURE RELIEF VALVE from the test ri
Subcontractor are not allowed to modify spring ranges or any modification, subcontractor has to go third party calibration agency if PRV fail due to spring/technical issues.
Result of the test shall be filed and recorded on the applicable test result form.
All successfully tested PRV shall be identified with a color code
The calibration validity will be 7 days from the start of calibration acceptance.

We linked following video for your practical consideration and theoretical consideration.