Most inspection programs do an adequate job of managing Pressure Relieving Devices (PRDs), without giving much consideration to the potential consequences of PRD failure to open or leak. Many plants inspect PRDs on preset intervals as recommended by inspection code API 510, and implement inspection practices such as API RP 576. But with the introduction of PRD risk-based inspection (RBI), these delicate instruments (yes, PRD’s are delicate & they are instruments) should be receiving much more dedicated attention. Are we really giving those PRD’s the appropriate amount of care they need?
Just seeking PRD compliance with codes and standards usually results in mediocre mechanical integrity and process safety. Companies must go further to climb the ladder to “excellence.”
- Don’t wait until a fire or explosion or injury to implement an effective PRD program.
- PRD “Excellence” does not mean “overdone or excessive.”
- PRD excellence consists of QA/QC, procedures, training, discipline, effective implementation, and constant re-evaluation.
- PRD excellence means your pressure-relieving system is adequate for the protected equipment.
- PRD excellence means you have an excellent relationship, communications, and QA process in place with testing and refurbishment shops, that conforms to your company standards.
Assessing Your PRD System
Rarely does our industry experience a failure, explosion or fire because of something that was caused by some new unknown phenomena. Failure incidents are obvious once you see them. We have a tendency to assume what we think, or what we want to believe, rather than what is actually there. We have the tendency to see what our minds want us to see rather than what’s really there. It's the same problem all of us run up against when we try to proof-read our own text. We see what we know the text means, rather than what is actually printed on the page. We become so familiar with what we are looking at, that we no longer see the problem.
People can look at PRD opportunities again and again without being able to see what can be improved. The real reason that Third Party Reviews (TPR's) and Cold Eyes Reviews (CER's) can detect issues that have been missed by on-site staff for years is that they don't know the routine. TPR’s provide a fresh set of eyes that have not been influenced by that attitude of, “we have always done it that way”.