Valve leak testing

[didi42]

Hello,

I am looking for a method to perform in line valve leak test, tipically for Emergency Shutdown Valves. I've been looking in many sources API, forums..., but I didn't manage to find an answer. I hope will find it here...

I have no issue for ESDV on gas lines for which we can use the pressure build up method (close ESDV, depressurize a section of pipe downstream the ESDV, monitor P and T and, using the equation of state PV= nzRT calculate the leak rate).
For liquid lines, I guess we can also follow the pressure build up method and use the equation provided in API 14B for SSSV leak testing (leak rate = V*ΔP /Δt*M).

So my questions are:
- Is it the correct way to proceed for liquid lines ?
- How do you proceed when multiphase fluid is concerned ?
- Do you have any feedback on valve acoustic leak testing ?

Thanks in advance for your help,

Didi