ASME B31.3 PWHT min thickness for Carbon steel

Question

ASME B31.3 PWHT min thickness for Carbon steel

engr2GW (Petroleum)

(OP)

25 Jun 23 16:07

Hello, The min thickness for PWHT to be required used to be 3/4 inches. I only have the 2012 version of the document. Has it increased? I saw a document where 0.98 inches was required as minimum, but there was no reference. Has it changed from 0.75 inches?

Thank you in advance

As much as possible, do it right the first time...

weldstan (Materials) · Answer 1 · 2023-06-25 17:30:30

For PNo 1 no minimum thickness provided 200 F preheat for T > 1" as I recall. Pretty much unchanged for other P Nos.

weldstan (Materials) · Answer 2 · 2023-06-25 17:35:42

You must use proper engineering judgement regarding the operating parameters as to whether you should PWHT.

engr2GW (Petroleum) · Answer 3 · 2023-06-25 17:45:49

Thank you for the response and advise. Much appreciated.

As much as possible, do it right the first time...

Dhurjati Sen (Materials) · Answer 4 · 2023-06-25 21:28:08

It is greater than 19 mm (3/4 inch) still.

DHURJATI SEN
Kolkata, India

DekDee (Petroleum) · Answer 5 · 2023-06-28 15:55:54

Read Table 331.1.3 in the 2020 / 2022 editions and you will have your answer.

SJones (Petroleum) · Answer 6 · 2023-06-28 17:52:23

https://www.eemua.org/News/New-EEMUA-guidance-on-P...

Steve Jones
Corrosion Management Consultant

www.linkedin.com/in/drstevejones

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ASME B31.3 PWHT min thickness for Carbon steel