A pressure safety valve (PSV) guards piping systems and pressure vessels against extreme internal pressure. When the pressure in a system reaches a preset value, the PSV opens, a part of the media is discharged, and the pressure inside falls to a safe limit. The valve closes as soon as the pressure reaches the valve’s reseating set point.
Periodic testing and adjustment of pressure safety valves are vital to preserve overall safety in Aerospace/Aviation, Oil and Gas, Chemical/Plastics, Power Generation, Steel Manufacturing, Water/Wastewater, and several other industries. A bench test conducted in a workshop is the most common test method for relief valves and safety valves. These tests typically involve disassembly, inspection and repair.
- Accuracy of recorded data — In the course of a standard PSV test, certain technicians cautiously observe an analog test gauge to obtain the PSV’s vent and reseat pressure. There is naturally a potential for human error to occur. Possibilities are that two highly skilled technicians watching the same test might record different results.
- Calibration record — Standard PSV tests have no documentation apart from the manual recording from a technician. In crucial industries like petrochemical, nuclear, and chemical industries, an archived, electronic record of PSV testing may be vital to validate proper safety precautions.
A Better Approach
Crystal offers an optimized solution. Upon enabling the PSV mode in ConfigXP, the customer’s XP2i increases the peak update rate from 4 to 8 readings/second. The steps below can be followed for testing pressure safety valves with an XP2i:
- Connect the XP2i to the computer using a USB to RS-232 cable
- Turn on the XP2i, open ConfigXP, and connect to the gauge
- Select Enable PSVtest mode and Enable Peaks
- Click Update Gauge
- Set up the test as normal, with the XP2i as the test gauge
- Repeatedly press the (peak) button until the “HI” indicator blinks in the upper left of the XP2i’s display. Now, the XP2i updates at 8 readings per second, constantly capturing and displaying the highest pressure it reads.
- Reset the peak value by pressing the (zero) button during venting of the system
- Increase pressure until the safety valve opens. It is not necessary to observe the gauge display during the test. The XP2i will display the opening pressure.
Once the test is complete, the pressure safety valve can be adjusted as normal, and then steps 7 and 8 must be repeated.
Options for an XP2i
Dual Line Display — The XP2i can be ordered with the DD option to simultaneously observe the valve vent pressure and the live pressure.
DataLoggerXP — This option can be purchased and activated to convert the XP2i into a 32,000 point data logger with an update rate of 1 reading per second, and a peak capture rate of 4 readings per second.
This information has been sourced, reviewed and adapted from materials provided by AMETEK Sensors, Test & Calibration.
For more information on this source, please visit AMETEK Sensors, Test & Calibration.