Forged Cross Fitting

[upod111]

Hi all,

I am working on a project where we are installing vent lines in a system. We will be tying these vent lines into an existing header. A question arose as to whether it would be acceptable to use a forged cross fitting to tie into the existing piping. The portion of the line where this tie would happen is open to the atmosphere and therefore provides no pressure boundary. Are there any issues, from a code perspective, of using cross fittings in a situation like this? I am not sure if I have seen cross fittings in the ASME B31.3 branch table, but I may be wrong. Thanks in advance for the help.

 

[LittleInch]

If its manufactured to B16.9 it's Ok - see para 303.

I see no issues, but they are not very common in my experience.

I don't get the bit about a pressure boundary, but it doesn't impact the use of a fabricated fitting.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[upod111]

Thanks for the info. That really helps me out. Kind of what I was thinking as well. As far as the pressure boundary part of the post, I was trying to say that the cross will be placed in a part of the line which has no internal or operating pressure. Hope that clears up what I was trying to say, haha.

 

[KevinNZ]

The problem with a cross is finding as SIF to use for piping design.

https://www.eng-tips.com/viewthread.cfm?qid=229007