odd pipe size

[Elkato531]

I need to connect onto an old stopcock with an unusual pipe size. The end I need to connect to has a male thread which is larger than 1/2" but smaller than 3/4". I'm guessing it might be 5/8" but I can't find any 5/8" fittings anywhere to test this. Unfortunately, removing and replacing the stopcock is unfeasible due to its location. At the moment, there is a piece of brass pipe with a brazed female fitting attached. This has been bodged into an old black pushfit fitting by filing down the pipe and widening the socket of the fitting. Its carrying mains pressure and has got to be a disaster waiting to happen.

Any ideas anyone?

 

[JimCrow]

solder a cutting of copper tube to the brass pipe you have

 

[Elkato531]

Can't get a 15mm fitting on. I've tried swaging a bit of tube and hammering it on but it won't go. Just had a thought though. I may be able to cut a 3/8" thread onto the brass. I think I'm right that 3/8 pipe is approx 17mm OD. I'll get back there next week and check it. Problem is that I can't afford to compromise the current arrangement until I have a guaranteed solution.

 

[newbuildinstaller]

http://www.ebay.co.uk/itm/Hydraulic...t=LH_DefaultDomain_3&var=&hash=item3a815df8a0

they do 5/8 - 1/2 adaptor

 

[Elkato531]

Thanks, that may be just what I need if its stainless steel plated. I'll give them a ring and check if its ok for potable.

 

[Jackrae]

That fitting will be mild steel with a zinc or cadmium plating since it's intended for hydraulic (oil) service.

Your best bet is to find a model engineer (with a lathe) and get him to turn you up a brass adapter piece to permit the transition from either the valve's 5/8"BSP to 15mm copper or to transition from your brass end to 15mm copper.

 

[HERTS P&D]

OP post pictures of the pipe work, is there another stopcock that can be turned off? allowing you to work on the pipework?

Andy

 

[Nige F]

Can't get a 15mm fitting on. I've tried swaging a bit of tube and hammering it on but it won't go. Just had a .

Anneal the copper then swage it and hammer it on . A pic would be good - it sounds like an old lead wiped connection -brass tail/lead pipe

 

[Jackrae]

In case you do not know - to anneal copper you heat it to what effectively is red hot then plunge into cold water. Steam will be generated and may shoot up the pipe, so be aware. Also the annealing process will leave a scale on the pipe to which solder will not take. So, to ensure there is good capillary action of the solder between the outer copper and the inner brass you need to clean up the inside of the copper before you fit it over the brass (which must also be scrupulously clean). Flux smeared onto the brass and copper before fitting together will also help.