ASME B31.3-PWHT on the same joint twice

[4872]

Dear Friends
Process Piping - Carbon Steel Piping - 6" Sch XXS ( 21.9mm )- PWHT done on the same butt joint twice. RT done after 1st PWHT-It passed.Is it acceptable to ASME B31.3?
What harm done to the joint ( weld metal & HAZ ) undergone PWHT twice, in terms of Mechanical Properties.... etc.
Thanks

 

[unclesyd]

You didn't mention the material as you know CS covers a lot of materials.
If your material is A106 no harm done.

Please comeback with the piping specification for a more definitive answer..

 

[SJones]

The only issue should be if supplementary essential variables are being applied and QW-407.2 of ASME IX has to be invoked: the original PQR may not have achieved the requisite 80% of the total time at temperature.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[stanweld]

RT after PWHT is not required for carbon steel under B31.3. refer to 341.3.1 (a).

 

[JAYDEE23]

Rt may not be required AFTER pwht but it is still required if dictated by the code...yes?

 

[JAYDEE23]

I think i see what you mean now Stanweld...it is not required again...sorry...

 

[4872]

Hi, Friends
MATERIAL - ASTM A106 / ASTM A53 x 6" x 21.95mm.
Pls explain "QW-407.8(b)a change of more than 10% in the no of PWHT heat cycle following the welding cyscle"

Thanks

 

[SJones]

Will you be flash welding the items? If not, don't worry too much about QW-407.8

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[4872]

Steve
I don't get your points. Pls explain Thanks

 

[SJones]

Look in QW-250 and identify where QW-407.8 is specifically invoked as a requirement.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[4872]

Dear Friends
Material - ASTM A106/A3
I've been going through ASME B31.3 Chapter VI- Try to confirm extent of MPI if any required beside RT/UT for Process Piping Butt Welds.
If MPI required, please advise respective section(s).

I've concluded RT as per ABS Rules.ABS Rules do not require MPI.
Thanks in advance.

 

[stanweld]

4872,
For MPI, refer to 341.4.3(b) and 302.3.3 (for castings).