How do I drain a section of pipe?

[mikely]

I have a section of 15mm pipe in my garage that connects to an outside tap. This pipe freezes during long periods of cold weather. I fitted a stop cock which allows me to isolate the pipework to prevent floods but the pipe still freezes and pushes open one or more compression fittings. How can I drain the isolated section of pipework out through the outside tap; is there a special valve designed for the job?

 

[Biguns]

I had this problem in my detached garage. Afer every thaw I found sections of 15mm copper pipe split. I changed the lot to plastic pipe, problem solved. It still freezes, even lagged, but no more burst pipes

 

[doitall]

It should have a draincock just above the stopcock, then you can drain down and leave it open.

If you have the tap with a double check valve, it's best to unscrew it and put it in the warm as the frost will kill it, (water gets trapped between the two checks)

 

[joinerjohn]

Easiest solution is to put a drain off point on the pipe, after the stop valve. Then all you do is turn the stop valve off and open the drain off valve. Let the water out, then close the drain valve. As there will be no water in the pipe now, it won't freeze.

 

[mikely]

Actually, I realise that the problem I probably have is that there is a check valve fitted in the pipe which won't allow water to drain through it. So having a drain valve low down still won't allow the pipe to drain.

I suppose I would have to fit the check valve above the stop cock? Is it essential to have a check valve in the system?