2 replies to this topic

[black friday]

Hi All,
I'm relatively new in the industry and have been assigned a project to bring all the sites PSV's up to date. I was hoping you could point me towards some existing procedures for field testing PSV's.
Is it sufficient to pressurise the vessel to the set pressure +10% and then check the vessel pressure gauge for indication of lifting? I'm concerned that as it's a gas change in pressure might not be to noticable. How should I quantify the flowrate? Is this necessary? When field testing should it relieve into the exhaust system for safety or to atmosphere so I can observe the lifting?
I'm working under Australian standards so while I've been using 521 for sizing, AS1271 is what I have to comply to.
The process situation is N2 gas at 120-800kPaa relieving to an atmospheric exhaust system.
Any and all help is greatly appreciated.

[Absolute Zero]

Your should refer to "Inspection of Pressure-Relieving Devices API RP 576." The test procedures are given in Appendix-B.

Regards

[bevjones]

Is it sufficient to pressurise the vessel to the set pressure +10% and then check the vessel pressure gauge for indication of lifting?

This is called hot floating, We sometimes do this when we cannot attach our inline testing equipment to the PSV. I have found this to be acceptable when the insurance inspector is in agreement that this test is ok.

The equipment I use tests the PSV when the vessel is at 80%+ pressure and give a readout of force, acoustic lift and also actual spindle lift. We test the PSV three times and from these indicators we can determin the average confirmed set pressure, and as long as the PSV is within Section I standards, I give a certificate for it, or adjust and retest.

Hope this helps.

bevjones
Tyco Flow Control