ASME B31.1 Paragraph B.4.1.1

[pflow]

ASME B31.1 Paragraph B.4.1.1 indicates that for socket weld connections the branch size must be the smaller of NPS 2 or 1/4 the nominal size of the run.

Would this prohibit, for example, installing a 1/2" sockolet on a NPS 1.5 pipe? Is there a difference if the branch terminates in a drain valve or instrument ?

 

[gr2vessels]

According to B.4.1.1, the maximum size of the branch is 3/8", if welded on a 1.5" pipe run. There is no mention of exception for drains and instruments. Sorry...

 

[Duwe6]

Just use a 1/2 or 3/4" Thread O'let -- the pipe-to-O'let weld is a full-penetration branch connection weld [not a socket weld], then use a threaded swagelok fitting to run tubing down to the drain valve. No socket-welding required.

 

[StevenHPerry]

I think you may not be considering the full context of "b.4.1.1". It's actually 104.3.1(B.4.1.1). I recommend reading the preceeding entries that get you to the 7th hierarchy level in!

I do not see a prohibition against 1/2" SOLs on 1.5" pipe. I think it is explicitly permitted by 104.3.1(B.2).

- Steve Perry

http://www.linkedin.com/in/stevenhperry

This post is designed to provide accurate and authoritative information in regard to the subject matter covered. It is offered with the understanding that the author is not engaged in rendering engineering or other professional service. If you need help, get help, and PAY FOR IT.

 

[gr2vessels]

Yep, Steve is right. I should have read the entire clause, not only the B.4.1.1.
Cheers,
gr2vessels