On Fri, 5 Jun 2009 22:53:42 +0100, "Andrew Mawson"
had this to say:

The black polythene water pipe went out of fashion in about 1984 if I
remember correctly,

I wonder why. My black polyethylene feed pipe was fitted around 1972
and hasn't given any trouble (at least in the last 26 years that I've
owned the place).

--
Frank Erskine