We want to use 1-1/2" 6000# threade
We want to use 1-1/2" 6000# threade
(OP)
We want to use 1-1/2" 6000# threaded half coupling welded into a 4" sch 80 pipe and use it for a level control float style switch. The half coupling interferes with the float movement. Can we reduce the length of the non threaded end of the coupling by 0.25" as long as we do not reduce the length of internal threads? If so how much of the non threaded end can we remove?





RE: We want to use 1-1/2" 6000# threade
One important aspect is the area reinforcement calculation. As per para 304.3.2 (b), calculation is required for this opening in the run pipe. Removing the end may make the fittings a non-listed one, requiring analysis per para. 304.7.2, but I think that's overkill. In the end, you couldve also made this modified half coupling from pipe. The 1.1/2" half coupling roughly equals a 2.1/2" Sch XXS pipe. Either way, you satisfy Code requirement as long as the calcs show there´s sufficient reinforcement. I dont see a problem with removing the 0.25" end. Make sure the internal weld reinforcement doesnt protrude too much into the half coupling causing the level switch to jam when inserting it.
Another aspect to consider, which cant be answered from your OP, is the service with respect to use of threading. B31.3 has provisions for the application of threads. However, the Code doesnt consider all aspects of your service. Therefore, threading should not be considered for certain critical services, like high temperature, lethal service, cyclic, etc.
RE: We want to use 1-1/2" 6000# threade
It's been said here before and is worth repeating: The value of the advice you get from the internet is worth every penny you paid for it.
RE: We want to use 1-1/2" 6000# threade
RE: We want to use 1-1/2" 6000# threade
http://www.bonneyforge.com/products.php?pg=branch&...
Notice that these items are Full-Penetration welded, and do not infringe on the ID of the main line. You've gotta stop using plumbers to build your pressure systems.
RE: We want to use 1-1/2" 6000# threade
A half coupling is designed to connect pipe to a screwed end.
It is not designed to connect a curved object ( your 4" pipe) to a screwed connection.
This is called a "threadolet" or a threaded integrally reinforced connection as per duwe6
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RE: We want to use 1-1/2" 6000# threade
Attaching a threadolet is overkill, and in some designs even inferior to a half coupling from a construction and cost point of view. Think of all those layers of weld metal that are needed. And what if the run pipe is 4" Sch 10S stainless steel? The pipe will show excessive deformation due to heat input. Just make sure the Code requirements for area replacement are cosnidered and that due consideration is given for the aforementioned service conditions.
RE: We want to use 1-1/2" 6000# threade
Hence, like many things here "It depends". I note your further points about review and area replacement etc, but without knowing all these crucial details is it not better to advise doing something which is more technically correct, safer and more robust?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: We want to use 1-1/2" 6000# threade
RE: We want to use 1-1/2" 6000# threade
A 1 1/2" on say a 24" line / vessel would be much more like it or even just a reducing tee for heavens sake.
There's too much doing things just because someone thinks its easier / cheaper / faster when in fact it's actually harder / costlier / less safe than doing it properly.
Anyway it's all IMHO.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: We want to use 1-1/2" 6000# threade
But I agree, from what I can ferret out, an olet or reducing tee is the way to go...
Nathan Brink