RT/UT before PWHT for P1 material

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ranajit chatterjee

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Dec 29, 2025, 2:39:40 AM (6 days ago) 12/29/25
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Dear Sirs,

As per ASME B31.3 clause no.341.3.1(a) mentioned P Nos.3,4,5A,5B,5C AND 15 materials examination(RT/UT) shall be performed after completion of heat treatment. But no information for P1 material whether NDT performed before or after PWHT.

Please advise can we perform NDT(RT/UT) before PWHT activity for P1(NACE/H2 service) material or not.


Regards,
Ranajit Chatterjee
9995018265

venkateswara reddy Desireddy

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Dec 29, 2025, 3:08:34 AM (6 days ago) 12/29/25
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Hi,
For H2 service you have to NDT RT/UT after PWHT. Better to do hardens also.





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james gerald

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Dec 29, 2025, 4:43:14 AM (6 days ago) 12/29/25
to 'ranajit chatterjee' via Materials & Welding
Just to share. As per ASME B31.3, PWHT is not mandatory for P! material provided certain conditions are fulfilled and not considered a service requirement. If it is a service requirement it is preferable to perform UT before PWHT & RT after PWHT since repair welds need PWHT if PWHT is a service requirement..

If it is ASME Sec.VIII Div.I, for P1 material as per UCS-56 Repairs are permitted after PWHT. Snap shot below.


Inline image
Inline image


Thanks & Regards

J.Gerald Jayakumar

0091-8838619635



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james gerald

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Dec 30, 2025, 12:28:23 AM (5 days ago) 12/30/25
to 'ranajit chatterjee' via Materials & Welding
Just be specific to question.

1. NACE MR0175 do not require mandatory PWHT unless Hardness requirements are met.
2. NACE MR0103 for Refinery sour service & associated NACE SP0472 for environmental cracking do not mandate PWHT for sour service snap shot below.
2. For H2 service PWHT is not a mandatory requirement as material selection are governed by Nelson curves (API 941).

PWHT for P1 material is optional and though if performed for P1 material due to service requirement (as dictated in the specification), UT/RT after PWHT is recommended for mainly Repair occurring after PWHT .

Inline image


Thanks & Regards

J.Gerald Jayakumar

0091-8838619635

On Monday, 29 December 2025 at 01:09:24 pm IST, 'ranajit chatterjee' via Materials & Welding <material...@googlegroups.com> wrote:


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ranajit chatterjee

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Dec 31, 2025, 3:09:39 AM (4 days ago) 12/31/25
to venkateswara reddy Desireddy, material...@googlegroups.com
For NACE service can we do RT/UT before PWHT ?

Regards, Ranajit Chatterjee
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