Stop cock

[marsaday]

I have bought a new house which i am renovating.

The water pipe comes up through the floor in the corner of the kitchen and has the stop cock attached to it.

This looks pretty old to me and i think it needs renewing. What will the pipe feeding the water be do you think. It was not blue plastic, but rather a black pipe.

I will get a photo next week, but i think this definitley needs renewing (stop cock i mean). So if i take it off will i be able to slip a new one back on ?

The house is brick built 1950's i think.

 

[HERTS P&D]

The question is, can you turn your water off outside on the pavement/garden?

Andy

 

[Charnwood]

What makes you think it needs renewing?
IIABDFI

 

[marsaday]

Well it looks very old and is currently off at mo as house has been a repo. Just think it needs to be a decent new stop cock.

I will be putting it on next week and hope i can access the stop cock on the street.

 

[Bosswhite]

Well it looks very old and is currently off at mo as house has been a repo. Just think it needs to be a decent new stop cock.

I will be putting it on next week and hope i can access the stop cock on the street.

Never like mucking around with the stop cock in the street, they have a tendancy to sieze up and cause a lot of problems.

 

[Homesafe]

Can you not turn off old one and install new above it and leave the old one open in situ?

 

[JohnD]

very often you can buy a new stop-cock in the same size as even a very very very old one, unscrew the headworks from the old one, and the new headworks will screw into the shell of the old valve. Plumbing is very traditional. Practice taking the old one apart on the kitchen table so you see how it is assembled.

Put a few turns of PTFE on the thread of the new part before you screw it in, and rub it slightly over the end with your finger to discourage it coming off.

Black plastic is probably Alkathene and much the same as the blue polythene used now, except that it is likely to be in Imperial pipe sizes, which are very close, but not quite identical, to current metric sizes, but if you can leave the old shell in place and just change the headworks, it will save you the trouble of finding an exact match. You can easily get brass stopcocks for 20mm and 25mm plastic, which will be similar to the one you have.

You may find that running down the side of the pipe, the maker, size and possibly year are embossed into the old plastic pipe.

If the new headworks don't fit, then by dismantling and polishing up the old brass, lubricating with Silicone grease, and possibly putting some PTFE tape on the spindle to help it seal in the gland, as well as on the threads, you can probably make it work and seal as good as new.

BTW to prevent a stopcock or other valve from seizing when it is going to be left untouched for many years, open it fully, then turn it back just a quarter or half a turn.

 

[marsaday]

Great post. Thanks for info. Also post on adding a new stop cock after the old one.

Yes i could do this as the stop cock is then on 15mm pipe. Will clean it up next week and have a closer look.

 

[yiano1234]

Yes, you can buy an adapter that fits on the black pipe and converts to copper. This is usually a type of push fit fitting, so you have to make sure there is enough black plastic sticking up from the ground. Also that it is free from any major scratches, as this will make it leak. You can get rid of any minor scratches by using wire wool.

Your local plumbing merchants should stock this fitting, make sure you know what diameter the pipe, as there are various sizes. Also as someone else said, you will need to turn water off in road to do this job. If the water turns off ok, and you have enough pipe sticking up from floor. Cut a small section and take it with you to the plumbing merchants.

http://www.drainagepipe.co.uk/products/mdpe-fittings-157/ this site also stocks the fitting you need.

Finally - make sure you use plastic cutters to cut pipe and not a hack saw. Push fit fittings like clean cuts.

Hope that helped - good luck!

 

[marsaday]

Thanks for this. Useful to know i can use a MDPE fittings.