To assess whether periodic 10-year replacement of propane pressure relief valves (PRVs) is necessary to ensure safety, PERC initiated testing and analysis of the performance of pressure relief valves for customer tanks. Battelle Memorial Institute tested the following objectives:
- Evaluate the performance of the PRVs that have been in service.
- Determine whether the recommended service life for PRVs can be safely extended.
This study uses a 300-psig air compressor, supplemental compressed air from self-contained breathing apparatus (SCBA) tanks, 50-psig surge tank, automatic pressure regulator, solenoid valves, pressure transducers, a flow meter, piping and tubing, and a data acquisition system. The rig can be modified to accommodate the various PRV sizes and has the ability to monitor the PRV start-to-discharge and reseating pressure using a water seal. The automatic pressure regulator has the ability to control the pressure increase at a rate of no more than 2-psig per second to facilitate monitoring the start-to-discharge pressure.
Project In Progress
If the research demonstrated that the probability of PRV failure is extremely low, then periodic replacement will be unlikely to improve safety. PERC will share the project results once completed with NPGA and other industry representatives, who can determine if changes need to be made to existing or proposed regulations.
Working with the PERC Retail Operations Task Force and Research & Development Advisory Committee, the report authors identified three additional tasks to see how PRVs might perform under more “real world” conditions.
For a condensed look at the report’s findings, simply download the fact sheet here.