Tolerance for pressure test

Hi Expert,
Please help me shown standard or code for tolerance for pressure test ?

I has a problem like this : Test pressure acc to drawing is 376 bar, but actual I carry out test pressure at 386 bar, this mean higher 10 bar. My client has question me that must be show tolerance for this issue.

Anybody help me. Many thank.

  1. Which standard subject to test? ASME B31.3 or API Spec 6A.
    Test pressure at holding time, the monitored shall not drop below the specified pressure, not mentioned above; even make sure no leakage found, no deformation …

  2. Did the test package install safety device at the test period or not?, please check this equipment.

In my opinion, your client may have concern at unit such bar or barg

Actual pressure test values should record of 386 barg in the pressure test certificate, in lieu of 386 bar, whereas barg are for gauge pressures, recorded from the gauge.

Thank You for your advise, Mr.Bien.
My Client has mention to tolerance for pressure test shown in Asme 31.3 para 302.2.4 (f) allowance pressure . I don’t know that is this correct ? If correctly , that mean pressure test may be over 33% ?


ASME 31.3 2016 para 302.2.4 (f), design pressure, it is a scope of design engineering.
Inspection and testing, acceptance criteria are in accordance with para. 345.4.

So now, I understand. Thank you Mr.Bien

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