Dear All

MPT of tube to tubesheet seal before and after hudrotest is normally performed. Now i would share some deviation from above method due to some geometrical reasons.
LPT is to be peformed instead of MPT and the same is more reliable than MPT if DPT is peformed after 1st pass & last pass, after expanding and after PWHT.

Is the above reasonig is valid, if yes then why. If No, then advice to go for our normal practice.

Best Regards

Ikram

1. I suggest to use MT (Magnetic Particle Examination) and PT (Liquid Penetrant Examination), or at
least, be consistent with terms: I assume LPT and DPT mean the same examination method.
2. I do not see requirement of PT nor MT in tube to tubesheet welds in Sect.VIII press. vessels
3. I do see the requirement in Sect.III (Nuclear) NB-5274 for PT of tube to tubesheet welds.

Mauro

Can you please provide the reason of neglecting the Magnetic particle test and liquid penetrant test. Also, please provide the alternative method of testing of tube to tubesheet weld after hydrotest as the exhanger is assembled.

Ikram

Ikram,

Please reverse your argumentation: Mauro is not suggesting to NEGLECT an examination, he is just stating that the questioned NDE is NOT required in Section VIII or Section III.

You need to check your Construction Code for the required NDE.
If in your case the NDE of tube to tubesheet welds is required by the Code or the Design Specification, just do it.
Certainly some materials or service conditions can make the NDE reasonable and useful.

The question wheter MT or PT is the "better" method could be discussed in this forum. I usually reject the use of MT on non-magnetic materials, and require PT in such cases The Code does not prefer any method, some purchasers do so.

DK