ASME B31.3 Section 323.2.2 (d) (1) (a)

[cmason]

Hello all,

I have a question regarding installation of non-impact tested materials at low temperatures. I have an A106B line that was installed incorrectly (should have been A333 gr 6). The line is low stress (<0.3 stress ratio), and so the minimum line temperature can be lowered in Curve B of Fig 323.2.2A. The minimum temperature for the line is -46C. This appears to meet all the requirements of B31.3 323.2.2, except for 323.2.2(d)(1)(a) - the line was originally pneumatically tested at 1.1x the design pressure, per code. However, 323.2.2(d)(1)(a) shows that the piping must be hydrostatically tested at 1.5x design pressure.

Since B31.3 states that regular hydrotesting occurs at 1.5x MAWP and regular pneumatic testing of lines occurs at 1.1x MAWP, is it inferred in 323.2.2(d)(1)(a) could have 1.1x design pressure pneumatic test substituted for the 1.5x hydrotest specified there? I do not think this is a safe thing to assume, but wanted to double check.

Thanks.

 

[BigInch]

I think you can do it, if you get your client's written permission.
Read up on the B31.3 code paragraphs specifying when testing is required and what all the alternatives are.

Learn from the mistakes of others. You don't have time to make them all yourself.

 

[DekDee]

cmason,
Hope this helps

Interpretation: 19-47
Subject: ASME B31.3-2002, Para. 323.2.2, Lower Temperature Limits
Date Issued: October 9, 2003
File: B31-o3-01347
ASME 831.3·2004
Question (1): In accordance with ASME B31.3-2002, when using a reduced stress ratio per Fig.
323.2.2B to permit use of non-impact tested materials per para. 323.2.2(d), can the hydrostatic
test required by para. 323.2.2(d)(1)(a) be substituted with the pneumatic test as permitted by
para. 345.1(b)?
Reply (1): No.

Regards,
DD

 

[cmason]

Perfect, exactly what I was looking for.

Thanks DD.

 

[CHouston]

I have a question regarding new to in-service piping. it is a 106B 2" and was wondering if it is mandatory to MT test the in-service pipe before you weld the two. I am working with the ASME b31.3 code?

 

[CHouston]

I have a question regarding new to in-service piping. it is a 106B 2" and was wondering if it is mandatory to MT test the in-service pipe before you weld the two. I am working with the ASME b31.3 code?

 

[metengr]

For in-service piping, mandatory no. Is it good design engineering? Yes. So, I would say yes.

 

[CHouston]

That's what I thought! I had a hard time finding it in the code. Thanks.