ASME B31.3-Process Piping-Is MPI Mandatory on Butt Welds

Date 12-14-2009 13:34

Dear Friends
Pardon me if my question sound silly and please answer in detail as much as possible
Project - Conversion of Tanker Vessel to FPSO Platform
Base Material - ASTM A106 x 8" x Sch XXS ( Group No P1 x P1 Butt Joints )
Visual Inspection prior to NDT done and Accepted.
RT >> PWHT >> RT-ASR Done and Test Results-Accepted. Is MPI Mandatory on Butt Welds Joints after RT-ASR?
What can possibly missout by RT which can be detected by MPI?
Thanks

By 3.2 Inspector (***)

Date 12-14-2009 14:29

Nalla,
Tight cracks can easy be missed on RT, so can lack of fusion.
Is RT >> PWHT >> RT-ASR required by project specs?

To the best of my understanding MT (or any NDT) after PWHT is not mandatory for P1 materials, unless of course if it is part of the specified random control.

3.2

By Nalla

Date 12-15-2009 05:26

Dear Sir
Can you pls refer me to the respective section of ASME B31.3?
Thanks

By 3.2 Inspector (***)

Date 12-15-2009 06:23

341.3.1,a

By Mikeqc1 (****)

Date 12-14-2009 19:55

Surface cracks.
MDK

By Danny Thornton Date 12-15-2009 17:01

The areas that were flat topped for the thermal couple have to be NDE for the porosity that can be aquired from the connection. I am just guessing here.