Water pouring out of inside mains stopcock !

[flutterbye]

Hi

As title said this happened because (despite all advice) I stupidly tried to close a stopcock shut. Actually, I was able to start the turning and loosened it up to about 3/4 of a turn with wd40 and opening/closing.

Then all hell broke lose as the 15mm pipe on the house side worked its way free. For all the water I didn't really know where exactly it was coming from so wife called emergency water company but I eventually managed to stop the flow to a tiny weep/drip. So water company will come round Tuesday morning or tomorrow if I'm lucky.

So my question is, it looked to me like the pipe coming from the floor was 22m and the stopcock reduced it to 15mm. But looking at screwfix I see they also sell a 20mm to 15mm stop cock. I don't trust my ability to measure the diameter of the pipe that accurately.

Are there any other clues as to its size? The house was built in 1974 and I can't find the outside water company stop cock so I hope the water company will show me when they get here.

 

[HERTS P&D]

What pipe is coming into the stop cock, copper or plastic?

Can you not re-fit the 15mm copper into the stop cock.

Andy

 

[simond]

The Screwfix unit is designed to connect to MDPE (blue plastic pipe) which I think postdates your installation.

Assuming your valve is connected to a metallic incoming main, the Screwfix stopcock isn't going to fit.

 

[studips]

if it's a copper riser, then by 1974 it should be metric 22mm, unless someone managed to find a bit of old 3/4"

does your stopcock have markings to indicate size?

it will be a new 22mm stopcock reduced to 15mm after the stopcock, a reducer soldered onto the 22mm going into a 15mm stopcock might be awkward as the riser would need to be dry before soldering, and the fewer joints on the street side of your stopcock the better.

as far as i can see, there is no such thing as a good quality stopcock nowadays. if anyone can educate me on that one i'd be pleased!

 

[HERTS P&D]

Looks like flutter bye has fluttered off. Was it something we said?

Andy

 

[studips]

i have that effect on people. sorry.

 

[smashngrab]

Looks like flutter bye has fluttered off. Was it something we said?

Andy

Maybe that should read 'Floated off '

 

[flutterbye]

Many thanks for the replies. I'd not wandered off for some reason the email notification didn't work.

Anyway, yes I think it is the blue plastic pipe ! I've never seen it before. Now that I know its mdpe (thanks a lot for that), it would seem screwfix do one at 25mm and another that I think converts 20mm mdpe to regular 15mm copper pipe.
http://www.screwfix.com/prods/32496/Plumbing/Brassware/Comap-Brass-Poly-Stop-Cock-15mm-x-20mm. Would the feed be more likely 20mm or 25mm ?

The only joints I've made before are compression 22mm and 15mm. Does the plastic part of this tap fit like a regular compression and so presumably it has an olive like any other? I mean should someone who is comfortable with copper compression be ok with fitting this or do I need some other tools/experience ?

As a second question, its currently leaking very slowly (one drip per 10 seconds coming from two joints). Is it likely to be safe for another day or two or is there a danger it might burst open by itself of from someone using the mains wate in the house? (Pipes around stopcock do vibrate a little when mains tap in sink is shut off from full to nothing ).

P.S. I wish there was a way to make (even small) donations on this site. Guys like you who help folk like me are saving us potentially many hundeds of pounds so would be cool if you could thank someone with a fiver here or tenner there.

 

[JohnD]

. Would the feed be more likely 20mm or 25mm ?

Measure it.

25mm is almost exactly an inch. Plastic pipe is measured by the external diameter.

Examine the pipe carefully. Bright blue is MD Polyethylene, black is Alkathene which is not the same, and a slightly different size. If it is black go to a local plumbers merchant for your stopcock, and get a few spare olives just in case.

 

[flutterbye]

Thanks John. Its definitely black and measuring as best a I can with adjustable spanner says its 21mm.

Perhaps its 20mm after all and so the screwfix one would be ok? Just that plumbers merchants are obviously closed today.

 

[JohnD]

If it's Black Alkathene, you really need the correct part. A local plumbers merchant is your best bet. It is an imperial size, not the same as the blue polythene which is metric. There is doubtless a mail-order supplier, but by the time it comes, you could have bought one locally.

 

[Terrywookfit]

If it's black it will be 1/2" Alkathene.

 

[flutterbye]

Its black but externally its 21mm. That is much larger than 1/2" .

I looked at plumbcentres catalogue and really don't know which stopcock to buy.

 

[JohnD]

Imperial pipe is (was) measured by internal diameter. Metric pipe is measured by external diameter.

That's why half-inch pipe is about the same as 15mm, and why old half-inch lead pipe is an inch thick.

 

[flutterbye]

So I just need to ask for a stopcock that takes 1/2" Alkathene on one side and 15mm copper on the other?