"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 2mm compression full-bore valve.
_________________________________________
Usenet Zone Free Binaries Usenet Server
More than 120,000 groups
Unlimited download
http://www.usenetzone.com to open account