water main All aspects of plumbing questions and answers, help, tips and information

[chaza]

i am about to do some work on a water main, the pipe is balck plastic of 21mm O/D, i am getting conflicting information, one says that in the 22mm plastic pipe i need a stifener, another says i dont. i now have a 25mm elbow(plastic) with 22mm copper fitting on the other end. i still dont know if i need a stiffener, although i am told there are about 6 types, one guy told me that he needed a sample of the pipe, which is im[possible to give until i do the job, so im in a bit of a quandry. i understand the differnt types are due to the wall thickness, but surely the black pipe will have a standard wall thickness that you could say was standard.


thank you

[oldie]

All plastic pipe usually requires a pipe insert or stiffener. If ommitted, there is a good chance that under pressure the pipe might come out of the fitting which could be interesting !

I'm a bit confused about you pipe sizes. 22mm along with 15mm and 28mm are usually only used for internal plumbing in the UK and not for water mains.

Domestic water mains in the UK are now mainly done with blue MDPE plastic in 20mm, 25mm and 32mm sizes.

It sounds like you black pipe might be old 3/4" imperial plastic piping. If this is the case, then there are plenty of adaptors you could get hold of depending on what you are doing.

If you are extending the main then a 3/4" to 20mm or 25mm adaptor might be appropriate. If you are terminating it, then a 3/4" to copper adaptor (15mm or 22mm) would be appropriate.

Don't forget to turn off the water supply to the pipe before you remove the fittings !

Best of luck !

[chaza]

yes your right it is the old stuff, but now i have my fittings i wanted to get a stiffener and i am told i dont need one for that pipe.