Dave wrote in message ...
My rising main is black alkathene (I think), the outside diameter is
close to 21.5mm - how can I find out what the bore is without removing
the fittings?

--
Dave S
(The return email address is a dummy)

Hi Dave,

The only bit of alkathene (or MDPE), I have laying around here is the blue
stuff. It is 20mm OD and 15mm bore.
I'm not sure if alkathene was in use in the days of imperial plumbing, if so
maybe yours could be imperial size hence the different OD.
If I had to guess I'd expect imperial plastic pipe to have had the same bore
as the iron pipes that it would have replaced.
I've just mesured a piece of 1/2" iron pipe and this is 21.5mm OD and
15.25mm bore. maybe your black pipe is similar bore?

Hope this helps

Bob