"Doctor Evil" wrote in message
...

"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?

Sounds like LDPE (black) rather than the current metric MDPE (blue) Two
main
types were used: Class C and Class D. Class C has a thinner wall than
class
D. You may find the type printed on the pipe.

In both 1/2" and 3/4" pipe, internal and external diameters differ.

BES (www.bes.ltd.uk) sell fittings to convert from Class C 1/2" to black
or
blue MDPE.

In your case the bore will be 1/2" (15mm). A standard 22mm compression
joint will go over the pipe, as long as you still use the existing pipe
insert. Wrap PTFE tape around the olive before tightening. If replacing
a
stop cock use a 22mm compression full-bore valve.

I left out. Use the existing olive on the black pipe, as that will be old
imperial 3/4". This can be used inside a 22mm compression fitting on LDPE
pipe.




_________________________________________
Usenet Zone Free Binaries Usenet Server
More than 120,000 groups
Unlimited download
http://www.usenetzone.com to open account