PR-2139 – Process Safety Relief Valve Testing and Certification – PDO

Safety Relief Valve (Pressure Safety Valve) testing is one of the most important elements of an effective maintenance program because the PRV is the last protection of equipment and associated piping and pipeline.
This document gives a detailed description of the methodologies to be followed in carrying out On-stream and Off-stream testing of the spring-loaded pressure safety relief valve and pop-test recommended practice.
This document should be adopted in combination with Shell-RBI which gives a detailed strategy to be followed for the inspection/ testing frequency.

The objective of this document is to provide a description of the steps to be followed for performing tests on the spring-loaded safety relief valves.

This document is applicable to all spring-loaded relief valves of conventional and pilot-operated design, capable of having their set-point verified by online or bench testing. Other over-and-under pressure protection devices such as bursting discs, buckling pins, vacuum breakers, pressure-vacuum valves, and anti-surge valves are outside the scope.

In the context of this document, no distinction is made between relief valves, safety relief valves, pressure relief valves, and pressure safety valves as defined in API RP 520. All new and used valves are included within its scope.
Relief valves protecting installations such as transmission pipelines and pressurized storage tanks, which represent major investments protected by relatively few valves, are outside its scope. The risks associated with these valves are considered to be best assessed on an individual basis using a methodology that models the consequences of “Failure-to-Operate-On-Demand” in a more rigorous way.