safety valve shall be installed in vessel during hydrostatic test?

[YuJie_PV]

i have a vessel constructed per ASME VIII-1, it is designed with a Presssure relief valve.
the manufacturer is checking with us if the PSV shall be installed during hydrostatic test, some engineers says it is required. i look through the ASME VIII-1, and find nothing related to this topic.
and now, i am confused.
Does ASME VIII-1 mandate the PSV to be installed during hydrostatic test? shall the PSV be tested together with the vessel?

Thanks in advance.

 

[LittleInch]

The test pressure must be higher than the set pressure of the relief valve so what do you think??

Some numbers would help here....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[YuJie_PV]

LittleInch,
Thanks for your response which remind me that the quesiton is obviously stupid.
i checked it again, and find that i have mistaken leak test with hydrostatic test.
sorry.
so my question is:
Does ASME VIII-1 mandate the PSV to be installed during leak test? shall the PSV be tested together with the vessel during leak test?

looking forward to your reply.

 

[r6155]

Always use PSV.

Regards

 

[YuJie_PV]

hi r6155,
thanks for your reply.
concur with you.
i just wonder if there are any clause in ASME code relating this topic.

Thanks

 

[Geoff13]

I'm used to large, field erected pressure vessels. Not sure my comments make sense in a mass-produced shop environment.

Assuming you are doing a standard UG-99 hydrotest, after holding the vessel at the test pressure to the AI's satisfaction, the pressure is reduced per UG-99(g) and inspected for leaks. The pressure test and leak test are the same event, and thus the operating PSV cannot be in place. As a result the Code doesn't discuss if a PSV should be used during the leak test.

These field pressure tests are highly monitored events. A PSV is great for preventing over-pressure during operation when no one may be watching minute by minute. However, many eyes are watching the pressure gauges during these field tests, and will be prepared to manually stop the pumps or open a value as the situation dictates.

 

[LittleInch]

My question is give me pressures.

MAWP?
LEAK TEST pressure?
PSV set pressure?
Type of PSV?

If your test pressure is within 10 % of the PSV, isolate the PSV, but monitor pressure very closely and use a small pressurising pump.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[r6155]

a) ASME VIII Div 1 UG-99 (g) The visual inspection of joints and connections for
leaks at the test pressure divided by 1.3 may be waived,
provided:
(1) a suitable gas leak test is applied
----------------------------------------------------------------
The hydrostatic pressure test can only detect water leaks, obviously. But this is not called "leak test". See ASME V.
The leak test is detected with gas.
There may be leaks during the pressure test not detected with water.

b) ASME V LEAK TESTING
T-1052 TEST SEQUENCE
It is recommended that leak testing be performed be?fore
hydrostatic or hydropneumatic testing.

Always Relief/Safety valve is present

Regards