NDT's Mandatory/Required by ASME Code 5

[rogervm]

I need help to understand what is mandatory by the ASME Code about Non Destructive Testing (NDT) during the fabrication of pressure vessels. When a technical specification for a Pressure Vessel is prepared, How to know exactly what NDT’s have to be included in that specification as mandatory?, What part of the ASME Code describe the NDT’s requirement?

Thanks in advance.

 

[davefitz]

"...local strain hardening increases the strength".. if the hydrotest was conducted at a temperature for which the material is ductile, and if both the design and fabrication were correct.

typical stress concentration factors for holes , branches, transitions is on the order of magnitude of 1.8 to 3.0, and for pre-existing cracks ( from welding process) is approximately 5. If the material is not ductile ( either because of too low a hydrotest temp, or incorrect fabrication , including lack of PWHT , lack of N+T ( when required), wrong weld electrode, "poisoning" of alloys ) then the stress at the tip of the pre-existing carck can grow to catastrophic failure during hydro test. So, if it down't fail, there is "proof" that the desing and fab and test was correctly accomplished.