Welding Different NPS Together W/O Reducer
Welding Different NPS Together W/O Reducer
(OP)
Good morning everyone,
I have a quick question regarding the image below. The line below is part of a glycol-water system, 304 SS material. The silver piping is 1" NPS SW and the magenta valves are 3/4" NPS SW. Operating conditions are 44 psig and 25 deg. F. The valve on the left side will transition to tubing and continue running back to two separate compressor KO drums. The valve on the bottom is just a bleed.
We recently sent the package off for approval and part of the Client's comments were that they wanted to change the 3/4" SW valves to MSW x FSW, and eliminate the 1"x3/4" swages. What they're thinking is that the MSW end will just fit inside the 1" socket on the cross and they'll just weld that together. I honestly don't think I've ever heard of someone wanting to eliminate the reduction fitting and just weld two different size pipes together. Obviously, I know the 3/4" MSW end will fit inside the 1" socket, but are there any welding concerns that I may not be aware of.
Since this is such an oddball request for me, it's one of those situations where I don't know what I don't know, so I'd just like to do my due diligence before proceeding.
Thanks for all your help.
I have a quick question regarding the image below. The line below is part of a glycol-water system, 304 SS material. The silver piping is 1" NPS SW and the magenta valves are 3/4" NPS SW. Operating conditions are 44 psig and 25 deg. F. The valve on the left side will transition to tubing and continue running back to two separate compressor KO drums. The valve on the bottom is just a bleed.
We recently sent the package off for approval and part of the Client's comments were that they wanted to change the 3/4" SW valves to MSW x FSW, and eliminate the 1"x3/4" swages. What they're thinking is that the MSW end will just fit inside the 1" socket on the cross and they'll just weld that together. I honestly don't think I've ever heard of someone wanting to eliminate the reduction fitting and just weld two different size pipes together. Obviously, I know the 3/4" MSW end will fit inside the 1" socket, but are there any welding concerns that I may not be aware of.
Since this is such an oddball request for me, it's one of those situations where I don't know what I don't know, so I'd just like to do my due diligence before proceeding.
Thanks for all your help.
"The only limits in life are those which we impose upon ourselves."
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RE: Welding Different NPS Together W/O Reducer
From a design standpoint, in my opinion, that is a question for the valve manufacturer.
Honestly, the pressure and temperature you stated seem well within reason to approve such a request.
The devil is in the details; she also wears prada.
RE: Welding Different NPS Together W/O Reducer
RE: Welding Different NPS Together W/O Reducer
I'm trying to get clarification as to what the reasoning is. If the reasoning is simply to keep all the 3/4" valves consistent as MSX x FSW (there are others in the project that have these same end conditions), then I would still suggest at least adding a 1"x3/4" SW reducing insert. I'm just not sure either why you'd want to skimp on such a minor thing like 2 swages.
"The only limits in life are those which we impose upon ourselves."
RE: Welding Different NPS Together W/O Reducer
I have seen people swage the end of pipe down so that they can butt it to another without an additional fitting.
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P.E. Metallurgy, Plymouth Tube
RE: Welding Different NPS Together W/O Reducer
Good communication is always key. Thanks again for all your help.
"The only limits in life are those which we impose upon ourselves."