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Harry Bloomfield[_3_] Harry Bloomfield[_3_] is offline
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Default outdoor taps and freezing

The Medway Handyman has brought this to us :
Harry Bloomfield wrote:
Stephen explained :
I was hoping to help by using one of those repair compression
fittings only I found I could not slide the nuts on. Do you think
that the ice stretched the pipe and made it fractionally wider? If
so, what use are these repair fittings?

The tap had a built in non return valve. I wondered whether these are
perhaps a bad thing? I realise there should be a valve but would it
be better fitted inside the house? If a tap was fitted without a
valve and the pipe was isolated and the tap opened, wouldn't the
pipe drain completely?


You could always fit the valve inboard of the point where it goes out
through the wall and inboard of an isolation valve. That way opening
the tap and turning the isolation to off should drain it.


Now if a tap with built in valve was used, would the pipe drain under
the same circumstances or does the non return valve require some
pressure to open it? Would water remain in the pipe that could freeze
and cause the damage that occurred?


I would have thought so (see above)

I am thinking of taking my sds drill and see if it will drill through
the concrete floor so that the pipe drop can be run inside the house
and go outdoors at the last minute.


I have a couple of taps outside and both only have the actual tap on
the outside, all pipework is inside. We have never had any problems
with freezing. There is a limit to how much lagging can help stop
pipes freezing. If it stays cold enough for long enough, eventually
the cold will get through and unless there is some heat source - the
pipe will freeze.


High pressure ring mains are quite common in food processing plants & usually
have an outside take off for vehicle cleaning. Water freezing when already
at 100 bar + static pressure is pretty unforgiving. Solution was a timer on
that outlet that opened a drain valve at regular intervals to keep the water
on the move so it couldn't freeze.


Another solution would to use electric trace heating - It is like a
tape which is run down the length of the pipe, under the insulation. I
think you can now get a tape which includes the facility to control
itself, turning on and off as needed.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk