How often do PSVs need to be tested?

We get asked for a single number, and there isn't one. A pressure safety valve in clean, steady service can run for years. The same valve in dirty, corrosive, or cycling service can foul up in months. The right interval comes from the service it sees, its own history, and the inspection program you have to answer to.

What drives the interval

• Service severity. Corrosive, high-sulfur, or particulate-laden streams foul valves faster and shorten the interval.
• History. If a valve has come in stuck, off set-point, or chattering before, it earns a shorter interval until it proves itself.
• Jurisdiction and RAGAGEP. Many operators align PSV intervals with their API 510 pressure-vessel inspection cycle and whatever their state or recognized good-engineering practice requires.
• Consequence. The more critical the vessel it protects, the more conservative the interval.

A common starting point is to tie PSV testing to the vessel's inspection cycle and tighten it for any valve in tough service or with a bad track record. The goal is simple: never let a valve go so long that you're trusting a relief device you haven't verified.

What a bench test actually involves

• Set pressure. Confirm the valve opens at its stamped set pressure.
• Blowdown. Verify how far pressure has to drop before it reseats.
• Reseat and seat tightness. Confirm it closes cleanly and holds.
• Certify in writing. Every valve gets documented as-found and as-left, and that paperwork goes into your inspection records.

How we handle it

We bench-test and certify PSVs and PRVs and schedule the work to line up with your inspection cycle — that's our PSV / PRV service. If you're still untangling the terminology, we also wrote up the difference between a PSV and a PRV. Tell us when your next inspection lands and we'll build the testing schedule around it.