[meupton]

I am replacing a sink and the plumbing is steel pipe. I bought a new set of valves that and nickel plated and a compression fitting. WHat is the best way to convert?

[massplumber2008]

Meupton:

What kind of sink here?

Working on water or waste lines or both?

Let me know.

MARK

[meupton]

Water supply. Kohler Kathyrn bathroom sink. Toilet too.

[massplumber2008]

Hi again...

Are your stops threaded?

Best here would be if you could post a picture of your setup... then can tell you exactly what fittings/shutoffs/tools, etc. will be needed.

Glad to help.

Let me know... MARK

[meupton]

Yes. They are threaded.

[meupton]

It has a multi valve that I bought at home depot on it now.

[massplumber2008]

OK... picture would really help here.

When you said steel... you mean pipes have threads and old shutoffs have threads and you just want to replace them... let me know.

[meupton]

Sorry. Not near the sink at the moment or I would send you a picture. Yes the shutoffs have threads just like the pipe coming out of the wall. The problem is I have purchased a fancier set of shutoffs that are compression fittings.

[letmetellu]

The iron pipes that the screw on valves are connected are probably 1/2 inch inside diameter, which is an out side diameter of 3/4 inch. The new valves you bought that are installed with a compression ring are probably for 1/2 inch inside diameter copper pipe and the outside diameter of the copper is 5/8 inch. Therefore you have a misfit, if you are only planning on replacing the valves and not any of the pipe I would suggest that you take back the valves you have and trade them for a 1/2 inch iron pipe thread valve. You can get them in a 1/4 turn ball valve, which I think are great, also you can get them in different outlet sizes. I would think that you outlet supply pipe is 3/8 inch outside diameter.

[massplumber2008]

I agree with letmetellu except that I am thinking that you have a 3/8" IPS brass piping there...not 1/2"... but still as he said, the particular kind of compression shutoff you have there simply won't work.

Best approach to this may be to see if you can positively shut the main water supply off to the house (open faucets to drain to lowest fixture in house) and then remove one of the shutoffs by holding the brass pipe with a small wrench and then loosening the old shutoff by unscrewing it counterclockwise with another wrench or pair of pliers. Then take that to local home repair store and match it up best you can and purchase what you need.

With threaded brass pipe/fittings, it is difficult to remove all the old stuff because you need to remove the last piece of pipe that stubs through the wall and that is not a good thing to do as you could disturb another joint behind the wall... and that can be disaterous! This is why I say you replace with a threaded type to match up to older type. If necessary can also check out things with a local plumbing supply house and see if they have any better suggestions.

Otherwise post a pic. When you can... ;)

Good day all...

MARK