In article ,
Bob Eager writes:
On Wed, 31 Aug 2011 15:07:38 +0000, AL_n wrote:

Can some recommend one, in particular, or advise of any types that
should be avoided? I want something that is as maintenance-free as
possible, because it's a real pain to access, being in an awkward corner
of the loft.

The hole in my header thank is about 1" diameter,and the threaded
portion of the valve is about 7/8" diameter, and then reduces down to
the usual thread diameter as found on compression fittings for a 15mm
pipe.

Are plastic valves (diaphragm type) suitable?

The small plastic Torbeck valves should probably be avoided. They are
good, but if the filter fails (which seems to happen after a while), the
slightest bit of grit will make them fail open (or closed!).

I've not had that problem, but I did have a plastic float arm snap
for no explainable reason sometime during the night, resulting in
continuous full flow filling, a failure mode which I had previously
considered unlikely. Fortunately, the overflow just about coped,
and thats something I always test since then by drowning the float.

To be honest, the basic brass one you have is probably the safest.

Yes. Failure is likely to result in a small overflow, at least
initially.

--
Andrew Gabriel
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