Required testing of PRD's on Positive Displacement Pumps

I would assume they'd fall under the plants general relief device testing/maintenance program.

Note - it's generally a good idea to not rely on the internal relief valves to protect the system. They're there to protect the pump not stop you from damaging your system.

No codes, just whatever the vendor recommended in his maintenance schedule.

As said these are rarely used as the primary relief path or at least shouldn't be precisely because they are not really "certified" and are sometimes very difficult to get at, never mind test or calibrate.

Asphalt is horrible stuff to pump and maintain a good path for pressure relief purposes due to it tendency to go solid... You need to steam or electric trac heat the proper pressure reliefs, but the pump is often not included.

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