Difference between leak testing (Section ASME V) & hydrotest / pneumatic test ( ASME Section VII

[Jaivishnu]

Hi I am newbie. I want to know if leak testing of pressure vessel as per Article 10 of Section V is different from hydrotest / pneumatic test of pressure vessels mentioned in UG 99 & 100 of ASME Section VIII Div 1 . Can i say that hydrotest of pressure vessels is a one-time activity or an activity performed annually or larger intervals, whereas leak testing of joints in pressure vessels is a more regular routine activity.
Basically i want to know if both these methods are applicable to pressure vessels and when to apply each method

 

[Geoff13]

Section V describes how to do NDE. The design code, such as Section VIII Division 1, describes what NDE is required.

Section VIII Division 1 is a new vessel construction code. The hydrotest is an over-stress test (1.3 times design pressure) and is only done once just before the vessel is turned over to the Owner.

NDE during the operating life of the vessel is not addressed by either of these codes. Doing an over-pressure hydrotest after the vessel has been in service is very, very rare. It is also very risky and should only be done after a thorough review by an experienced pressure vessel engineer.

 

[r6155]

1) Pressure test is not a NDE. The Manufacturer is responsible for the structural and pressure-retaining integrity (with pressure test)
2) Leak testing is a NDE and may be performed using vaccum. Please read ASME V

Regards