I asked some ChemEs and MEs the following questions about relief valve testing. We come across some RV programs and practices that we feel fall short of following any RAGAGEPs and thought it would be helpful to hear from engineers who manage these programs on a daily basis. Here is my scenario, and their responses follow.
Hypothetical Situation:
I have a PSM-covered process with a refrigerant as my highly hazardous chemical. I practice removing all my RVs every five years, throwing them in a dumpster, and installing new ones. The practice has shown that it is “cheaper” to replace the old RVs rather than have them tested with the chances they may fail and I would have to buy new ones anyway (e.g., the cost of a new RV is less than the price of testing and a new RV). The old RV gets no type of inspection, and neither does the vent pipe to the RV nor the vent pipe on the discharge of the RV. I do this every five years, as per an Industry Trade Association safety bulletin that OSHA has deemed a Recognized and Generally Accepted Good Engineering Practice (RAGAGEP). These industry bulletins (2 different ones from the same organization) state the following regarding the inspection and testing of RVs:
6.5.4 Pressure relief valves shall be replaced with a recalibrated valve or cartridge at intervals not exceeding five years.
and
4.9.7 Pressure-relief valves discharging to the atmosphere should be replaced or inspected, cleaned and tested every five years of service. Testing should be done by an authorized testing facility.
The questions for this group are…