In article ,
Tim S wrote:
Gordon Henderson coughed up some electrons that declared:

Another daft question, (thanks for all the screwfix shop replies - works
a treat!), but the incoming mains to our house is a black semi-flexible
pipe of about an inch in external diameter. This has what looks like an
odd coupling that looks like some sort of compression joint to 15mm pipe
where I fitted a stop cock some years back... (works fine).

Not daft - been there done that.

Mine was 1/2" black alkathene (phone call to water board who took a stab at
identifying by description). As other's have said, yours is almost
certainly the same.

Going by other posts - it may be standard (modern) MDPE piping, but
black rather than the usual blue...

Our water pressure is high (8 bar), but flow rate low (under 10 litres
a minute) I think due to some external restriction in the pipe work -
which I'm not prepared to dig up at this point in time.

I would say you have a restriction. I have 12-13m of that pipe at 7 bar and
I can get 50+l/min out of it.

More investigations earlier this evening found a crudded up stop cock
outside the house, but on our land. We did get the waterboard to check
the street valve and connection when we moved in. I think it's this
external siezed up valve that's cusing the restriction. Don't have the
means to dig it up right now though.

I've seen the results of a leak in a neighbours house...

What I was really after was moving the system to mains fed rather than
tanks in the loft... The bath can fill quicker by gravity than the tanks
can re-fill from the mains.

Thanks for the links - good reference though. I'll pull the dishwasher
out tomorow (Which the pipe runs along the side of) and get a better
look at it and see if there is any identifying marks and I'll be better
able to size it then too.

Gordon