Iron to copper pipe seal - replacing Stopcock

[silvergrowler]

Any advice on how to seal an iron to copper adapter onto an iron incoming mains water pipe in a house (1959 built in this case) in order to replace a stopcock?

The stopcock (Iron to copper) was seized and so had to be removed and a new stopcock fitted, but it appears almost impossible to seal a new stopcock onto the Iron (female) connector without a minor weep developing. An alternate solution would be to fit an adapter (male 1/2" iron to 15mm compression).

I understand hemp shouldn't be used anymore with sealant but are there alternatives? is PTFE tape better. For jointing compounds are Boss Supergreen or Jet Lube V2 plus OK or are there better products for this? Should a washer be used between the flange on a male adapter and the end face of the female pipe as the adapter thread doesn't seem to go to the end of the adapter.

Any Tips? e.g does the pipe thread need to be dry etc.

Is a ball valve suitable/legal as a stopcock, or do they have to be the sort with washers in?

Any suggestions would be helpful as the leaks are driving me and the plumber who is doing the job mad!

Thanks

 

[AWheating]

use ptfe tape. dont mix iron and copper fittings. fit a normal stop tap if possible as it gives more control over flow rates.

 

[mountainman]

Youve got a plumber on site and he doesn't know how to fix it ??????

 

[JCplumb]

:iagree: I was thinking the same thing. Plumber on site, but customer coming online to find how to sort it...

 

[Mike Jackson]

Perhaps the builder sorry plumber hasn't come across iron pipe before.

 

[AWheating]

probably inexperienced in dealing with these things, we all need to learn and ask advise.

 

[silvergrowler]

use ptfe tape. dont mix iron and copper fittings.

PTFE did the job. Thanks.

If Copper and Iron shouldn't be mixed (in this case like for like replacement iron to copper- the old stopcock was copper direct into Iron unless it just looked like copper but then it was connected to copper) then for my own interest how should the incoming Iron pipe to the stopcock be attached to all the copper inside the house? is there some sort of special connector or isolating bush to be used? Theres no iron piping in the house just the rising main.

Thanks for replies the plumber has the qualifications but not much experience with Iron so we just wanted to check.

I do little thing like replacing washers and taps myself but jobs like this are WAY beyond me.

 

[PlumbBobBob]

i'm sure the stopcock would have been brass which is fine for separating iron and copper imho.

 

[silvergrowler]

i'm sure the stopcock would have been brass which is fine for separating iron and copper imho.

The adapter used was described as male iron to copper conversion so may well be brass and not copper.