In message , Tim Lamb
writes
Black alkathene used *Johnson fittings* (I think) when it was first
introduced.

Thanks to all. I have passed the various bits of info on.

I am not sure whether this outdoor pipe was a standard obsolete type.
Certainly, I remember trotting round a lot of plumbing suppliers with a
pipe end and a lot of shaking heads.

I know his plumber said the house plumbing used some peculiar
non-standard marine pipework.
--
Bill