Stopcocks emergency question

[EricP]

Just a theoretical question that interests me if someone with the knowledge could answer.

If it is necessary to turn off the water mains on the road, and for some reason this is impossible, (No key, tap seized, can't find it), and the property has the modern plastic supply, usually terminating under the kitchen sink. Can you compress the polythene? pipe to stop the water? Perhaps with two wooden blocks and some sort of cramp?

(Assuming that there is sufficient poking up through the floor to actually do this?)

Cheers

[Tony Williams]

That's what the water board did next door when they replaced the external stop c*ck. [1]

They had a sort of vice/mole grip thing, with two cylinders instead of jaws. The cylinders were about 30-50mm OD and they just squeezed shut the polythene pipe coming from the main.

[1] British Gas subcontractors mole'ing for a new gas main, quietly going down the edge of people's drives instead of in the road. Hit the stop c*ck dead-on, instant flood.

[EricP]

Many thanks for the information, I have filed it for future use. I just wondered if the stuff would damage by this, causing further problems. It would make life a bit easier having the option to do it. :))

[Phil L]

You'll slow it down, but it's unlikely you'll seal it properly without damaging it, alkathene will bend a little, but the water pressure inside it makes it much tougher to compress unless you have the proper equipment...anyway, there is a stop tap inside the property, usually where it enters the building, maybe yours is below the kitchen cupboard bottom? - if it is, you might want to cut a bit of chipboard away, for future emergencies.

[EricP]

I know that you numpty! I wanted to shut off t'water before t'stopcock when the mains tap is US. :))

[the_constructor]

If you go to a Motor Factors or Brake Suppliers, you can buy a special tool that garages use to compress the brake hoses with. I had one back in the 60's when I used to specialise in brake repairs.

[EricP]

And now you have mentioned that, a neighbour has such a thing gathering dust in his garage. :))

[Robbo]

Compressing MDPE 20 or 25mm dia pipe with a hose clamp for brake pipes would near impossible given the high psi of the water and possible flow through if inadvertently water was flowing, say to a flush in a toilet. In my experience if you whine nicely at your local water board that the stop c*ck seems seized they will probably send out a man to inspect and rectify or turn off the water for you. If you need to stop the supply temporarily why not freeze it and install your new stopcock above the frozen section in the comfort of your own kitchen.

[Robbo]

Have a look at