X ray after stress relief in sphere
X ray after stress relief in sphere
(OP)
Hello, acording to ASME VIII section 1 and 2, after performing the Stress relief procedure, does it comand to do more X ray?
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X ray after stress relief in sphere
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X ray after stress relief in sphereX ray after stress relief in sphere(OP)
Hello, acording to ASME VIII section 1 and 2, after performing the Stress relief procedure, does it comand to do more X ray?
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RE: X ray after stress relief in sphere
RE: X ray after stress relief in sphere
RE: X ray after stress relief in sphere
jt
RE: X ray after stress relief in sphere
RE: X ray after stress relief in sphere
Just depends on how critical the vessel is perceived to be. Or if it's fabricated of V-modified materials. Though I hear claims that the cracking issues of a few years ago have been resolved.
But... the OP's question was strictly Code requirements, not "good practice" or owner's specification related.
jt
RE: X ray after stress relief in sphere
My initial question was: If the code orders or not to RT after PWHT?
RE: X ray after stress relief in sphere
RE: X ray after stress relief in sphere
especially on heavy wall where RT is so expensive
RE: X ray after stress relief in sphere
For Section VIII, Div 1; NO!
RE: X ray after stress relief in sphere
You either read the PWHT charts to understand what time and temperature was applied to the pressure retaining item or you can use hardness testing to check if the weld and surrounding base metal heat affected zone have been tempered from PWHT.
RE: X ray after stress relief in sphere
You said some specifications call for NDE before and after, can mention wich ones please?
RE: X ray after stress relief in sphere
jt
RE: X ray after stress relief in sphere
This is no joke....after hydrotest
RE: X ray after stress relief in sphere
Patricia Lougheed
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RE: X ray after stress relief in sphere
RE: X ray after stress relief in sphere
Would that job you currently have be fabricated of a PWHT limited material - perhaps one for which the welding procedures are only qualified to three or four PWHT cycles?
That's typically where I'd expect pre-PWHT RT requirements. When you perform pre-PWHT RT, then it is not unreasonable to ask for post-PWHT NDE - whether thats RT, PT, MT, shear wave, etc. is up to the spec writer. As mentioned, if its in the spec, then the owner is willing to pay for the extra effort in order to receive a more reliable / maintainable vessel.
jt
RE: X ray after stress relief in sphere
Luis,
According to ASME Sec VIII,DIV-1,welds have to be radiographed,as a part of the design efficiency, e.g RT-1,RT-2.... and others. No code will specify at what point of fabrication NDE (such as RT) has to be done, if so that becomes too binding. Often clients spefication, which is more suited to service conditions, specify if RT shall be done before or after PWHT.
Usually from codes perspectives for steels which are not prone to serious cracking (e.g P1,P3,P4,P5A) RT shall be done on completion of fabrication, prior to PWHT. For steels which may develop cracking upon PWHT, through secondary hardening, such as P5B, P5C additional NDE (RT/UT or others) should be done following PWHT, to safeguard the components.
From ASME perspectives, for PI materials RT shall be done prior to PWHT. If there is any additional project requirement of RT after PWHT it is above the code requirements.
RE: X ray after stress relief in sphere
we are used to RT after PWHT as it is not all that uncommon.
But after Hydrotest?
we have had to WFMT after hydrotest before for the same Wet H2S.
RE: X ray after stress relief in sphere
jt
RE: X ray after stress relief in sphere
For other P group materials, ASME B31.3 does not specify whether before or after PWHT so either would be permissible.
In sour service (both vessels and piping) I have seen many end user specifications that require that examinations be performed both before and after PWHT or that the be performed after PWHT. Some require that these examinations shall be no sooner than 24 hrs after PWHT and some specify 48 hrs.