Recommended sizes for copper pipe unions & nipples

[GreensandsParticipant @greensands]

I am sure this question has been asked many times before but can anyone suggest a useful source of information on the sizing and making of brass union nuts and pipe nipples for the typical range of copper tubing used in ME. My immediate requirement is for use with 3/16" diameter copper pipe using nuts turned from 3/8" brass hex.

[GreensandsParticipant @greensands]

[Simon CollierParticipant @simoncollier74340]

Union nuts for 3/16 pipe are 7/16 Hex with 5/16 32 ME threads. You should find information on line. Maybe have a look at Steam fittings.co.uk website for the sizes. The detailed info is in Stan Bray's book on building locos and probably Kozo's books too.

[GreensandsParticipant @greensands]

Hi Simon – Thanks for the info. I was rather hoping to use 3/8" Hex as in my opinion 7/16" hex nuts can look a bit 'clunky' on a 5"G model. One way around this I know is to use a stub or short length nipple in place of the standard design where the tail of the nipple passes out through the hex nut. The problem with usingthe standard design of nipple however is the precious lack space when using a 3/8" Hex nut.

[MichaelRParticipant @michaelr]

This was posted for a similar question on this forum, it may help you.

[Simon CollierParticipant @simoncollier74340]

How about nipples and olives rather than standard pipe tails. You could try 1/4 olives parted off with 45 degree tool, 5/16 x 40 threads as you will have very little wall thickness, and nipples with a 3/16 hole opening to 1/4 for the olive and threaded to match the 3/8 nut. Brian Wilson uses this system in his gauge 1 Eric book.

[GreensandsParticipant @greensands]

Hi Simon – Thanks for the info. Does anyone have a copy of Brian Wilson's book on the building of Eric? Have done a search oe ebay and other likely sources but to no avail. A previous post suggested that Brian Wilson was at one time a member of this forum. Has anyone had any recent contacts with him?

[Simon CollierParticipant @simoncollier74340]

PM me with your email address, and I can send you relevant bits.

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