Hello, Guys. I am new here and have
Hello, Guys. I am new here and have
(OP)
Hello, Guys. I am new here and have, hope so, a silly question.
In a branch connection for a pipeline that I am checking for pre-commissioning I found that the run pipe is API 5L, X-52 and the branch pipe is API 5L, grade B.
Looking at the construction code, ANSI B31.3, and associated specifications I didn´t find no information about this but, four out five examples shown in the code´s Appendix H highlight that both pipes have the same specification.
Treating this with the designer has take some seriuous discussions but no agreement has arouse.
Please, I´d like to know your comments. Thanks in advance.
In a branch connection for a pipeline that I am checking for pre-commissioning I found that the run pipe is API 5L, X-52 and the branch pipe is API 5L, grade B.
Looking at the construction code, ANSI B31.3, and associated specifications I didn´t find no information about this but, four out five examples shown in the code´s Appendix H highlight that both pipes have the same specification.
Treating this with the designer has take some seriuous discussions but no agreement has arouse.
Please, I´d like to know your comments. Thanks in advance.





RE: Hello, Guys. I am new here and have
What is the size of the Run Pipe?
What is the size of the Branch Pipe?
Is this pipe already purchased and at the jobsite?
Sometimes its possible to do all the right things and still get bad results
RE: Hello, Guys. I am new here and have
As I wrote, we are in the pre-commissioning stage, so the pipeline is already constructed.
The run pipe is 26" and 0,4382" thick. The branch is 6" STD. The reinforcing pad is the same material and thickness as the run pipe, in accordance with the available records.
Thank you for your fast reply.
RE: Hello, Guys. I am new here and have
If this is a pipeline then it should be B 31.4 or 31.8 as the design code, not 31.3 which is a piping code.
I can't see a big issue, but "branch connection" is a bit vague. Do you mean literally a pipe and re-pad or are you using a weldolet.
A drawing, sketch or some design info like penn piper says makes it all much clearer.
What is your concern?
So long as the branch pipe is properly sized, the different material grade is irrelevant as far as I can see.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Hello, Guys. I am new here and have
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Hello, Guys. I am new here and have
Here's a picture of the mentioned branch connection. The pipe run is 26" grade X-52 and the branch is 6" STD, grade B.
This is a valve station that the customer required to be constructed in accordance with ANSI B31.3 since it is inside a cryogenic complex. The pipeline was constructed in accordance with ANSI B31.4
My concern is related to the materials compatibility from the mechanical point of view. The project´s piping class asks to mantain this during the pipeline (NGL) construction.
I agree with Mr. David´s comment related to the WPS.
Again, thank you all.
RE: Hello, Guys. I am new here and have
RE: Hello, Guys. I am new here and have
Do you actually mean designed and constructed?
If so the wall thickness of this section of pipeline will be thicker than the B 31.4 section due to the way the two codes work. This is normally not a good idea as it can impact of the potential for pigging due to change in ID.
Also these types of branch connections are not a preferred technique due to the potential for either the pipe or bits of the welding to stick down into the main pipeline thus causing damage to any pigs. On piping no one really cares but pipeline does. Use of a reducing tee or a weldolet is preferred.
The fact that this thing is inside a facility should be irrelevant.
So long as the design and the WPS is Ok, then there shouldn't be an issue. Having a smaller diameter pipe with a lower SMYS isn't unusual.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Hello, Guys. I am new here and have
RE: Hello, Guys. I am new here and have
Your comments made me to see it better.
RE: Hello, Guys. I am new here and have
1) Put something decent in the title box - this one should be " Header and branch design"
2) Try to put relevant information and pictures, drawings etc in the OP. Which design codes matters and pictures / drawings tell a thousand words.
3) Some sort of background and what the issue is and what you've already considered helps to focus the answers or they can go a bit off the wall, or not get very many.
4) some feedback on what you're going to do or did do, even if it's weeks later is much appreciated - all the comments come free so decent feedback is part of the bargain you strike.
LI
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Hello, Guys. I am new here and have
RE: Hello, Guys. I am new here and have
RE: Hello, Guys. I am new here and have
"My concern is related to the materials compatibility from the mechanical point of view. "
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Hello, Guys. I am new here and have
RE: Hello, Guys. I am new here and have