How to decide the face to face dimension of a NPT/SW Type Coupling

[qiuniu]

In our project, a coulping with NPT/SW connection is used.
In B16.11, dimension for threaded or SW connection on both ends is defined. However, for the dimension of NPT/SW type coupling, how to define the face to face dimension?

Thanks.

 

[GenB]

check mfr's data bonny forge to start
it should be the same as threaded coupling

 

[qiuniu]

Thanks for your reply.
Can you be more specific about mfr's data bonny forge?
I looked up the homepage of Bonny forge and did not find relevant information.

 

[pennpiper]

Go here and look at all of the dimensions for Couplings.

http://www.pennusa.com/pennpage/directory/forgecat/forgcatl.htm

Look at the same size across the board:
a). all the Threaded Couplings have the same end-to-end dimension for a given size
and
b). all the Socket-Weld Couplings all have the same but different end-to-end dimension for the same given size

c). this suggests to me that the manufacturer makes one length "Blank" for Threaded Couplings and a different length "Blank" for Socket-Weld Couplings

d). what you want is a mix, Threaded on one end and Socket-Weld on the other end.

d). Contact your supplier and ask if a Threaded by Socket-Weld Coupling is available. If it is not made then you need to find a different method to change construction.

e). The different method might be to make the transition from Threaded to Socket-Weld is via a Threaded-one-end (TOE)Nipple.

 

[qiuniu]

Thank you very much for you reply.
Actually, the reason for this one is that we are trying to establish a standard database for piping components. I wanted that for vendors, what is the common practice for this kind of situation.

Thanks anyway.

 

[pennpiper]

I repeat,
Make the transition from Threaded to Socket-Weld via a Threaded-one-end(TOE) Nipple.