Testing (Hydro) of a spare valve 1

For us in the marine industry, a valve needs to tested prior to installation. The classification society will witness the test. Contact pattern or hydrostatic testing are acceptable.

I don't think ASME has jurisdiction here as they're mostly involved in the construction of the valve.

What type of valve are you discussing? Generally a hydro test would have already been done and certified by the original manufacturer. Why do it again? unless its design requires it.


*** Per ISO-4126, the generic term
'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

This falls into the custom and practice part of life.

There is no real reason why this valve needs a hydro test unless someone has lost the previous test results.

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Also: If you get a response it's polite to respond to it.

I suggest that the reason I would recommend testing a valve that has been in store for a period of time is that (often) valves are not stored particularly well and it is much better to find out that the valve is not working as it should BEFORE it is installed into line and NOT afterwards! The problem with hydrotesting is that it is not always possible to get all the test water out after testing, so residual test fluid will remain in the valve and, potentially, corrode sealing faces whilst it sits quietly in store, awaiting its time to shine. Indeed I suggest that with a trunnion mounted ball valve it is impossible to get all the test water out unless it is purged on dry gas or similar.

These days there are a lot of good preservation products on the market that can inhibit corrosion in the store, but they need to be applied correctly and maintained, and each of these aspects is as important as the other. Irrespective, I think that a quick pressure test prior to installation pays dividends.