Connecting from imperial to metric copper pipes ?

Sep 19, 2006 8 Replies

(I'll assume you meant 15mm, not 12mm - metric are outside diameter, imperial are inside IIRC)

And for a followup, putting fittings on a pipe which has been expanded by frost.

(ans: get a solder fitting, press a suitably sized socket into it to make it larger. Maybe do this in a couple of stages)

(of course this won't work if 1/2" pipe is smaller - I don't know...)

cheers, clive

The message from "repro" contains these words:

Take a bit of each pipe to the plumbers' merchant and get an adaptor.

Is there a conventional way to join new 12mm copper pipes to old imperial



1/2" ? Is the difference too small to worry about ? Would compression be better than soldered? Opinions/wisdom welcomed Ta David

15mm to 1/2" you can use the same Yorkshire fitting * 22mm to 3/4 you need an adaptor fitting 28mm to 1" you can use the same Yorkshire fitting

(* I wouldn't recommend endfeed as the 15mm socket is a tad tight on the 1/2" pipe so nice that the solder is already in there)

AWEM

oops, yes 15mm, sorry. Thanks for the tip Clive. David

It is smaller. The difference is small enough that metric fittings generally work on imperial 1/2" pipe. This is less true for 3/4" where some form of adaptor is usually required to 22mm.

On Tue, 19 Sep 2006 19:12:00 -0000 someone who may be "repro" wrote this:-

In addition to the answer on soldered fittings, from memory with compression fittings special olives are sold for 22mm fittings to go on to 3/4" pipe but the other sizes will work as they are.

On the rare occasions I've come across 1/2" copper pipe I have found that it is very slightly bigger than 15mm, so that fittings are hard to mount.

In message , Ed Sirett writes

Yup, I used to sand down the outside of the pipe and the inside of the fitting but TBH it's a lot quicker and easier to keep some adapters in the plumbing box.

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