mains water pressure reducer

They are common some some shower heads and toilet cistern valves. The work well, although don't reduce the pressure as such, just limit the flow.

(you can get pressure reduction valves as well, which can reduce water hammer and flow noise etc)

If it's just the kitchen tap just close down the service valve on the pipe to the tap. This is assuming you do have in-line service valves on all the pipes where you may want to replace or service taps or maybe the components in the toilet system.fitted

If you want a more adjustable flow you're not going to do better than a pressure reducing valve.

You can fit a pressure reducer on your "rising main" (I have an adjustable PR, with a pressure gauge) or one can be fitted in your water meter (ask your water provider).

It's the water analogy in reverse! A resistor will only reduce the voltage if there's a load. Close the tap and the pressure will be just the same as at the other side of the reducer/resistor.

Bill

Well when I had the meter fitted they automatically tested it for leaks and found none. And so far none since. It seems to be lead from the meter to just a little up the wall in a cupboard in the kitchen, where istis connected to copper. However in the main, I did have a stopcock fitted but the wood it was screwed to has rotted and its now only on the lead, which worries me. Its also very stiff to turn, damned hard water again, but has reduced the pressure by partly turning it down a bit. Not ideal, since this does the same to the fill of the loft tank as well. Brian

That will reduce flow rate, but not pressure. But its nice and cheap.

I think you can get proper pressure regulators - essentially a valve operated by pressure - for mains water. I know my pressurised tank features such.

That works, but does tend to make for very noisy water flow on high pressure supplies. The flow reducing discs seem to make less noise.

Yup, when I rebuilt my upstairs bathrooms I stuck one in on the cold main feed to drop the pressure from 6+ bar to 3 ish. That kept the system quieter and matched the output pressure of the PRV on the hot water cylinder, so showers and mixer taps etc have a fairly close pressure balance.

It is the thing in the bottom right with the green cap:

We have about 9 or 10 bar mains pressure which, together with a big pulse pressure "knock", was enough to damage an expensive Mira shower. Installing a hammer arrester has taken care of the pulse "knock", and the shower is now doing well.

A heating engineer who will soon swap our combi boiler has offered to put in a pressure reducing value (presumably like the one in your photo) in the water main indoors. Is there any value in doing this?

Yes this is the problem, if I turn down the main stopcock there is noise whenever the cistern refills and I only want to reduce the pressure and flow at the kitchen tap.

I forgot the washing machine and outdoor tap Tee off the 15mm pipe to the kitchen tap. I would only want the reducer on the leg of the compression Tee that feeds the kitchen sink tap. The cistern fills off an earlier Tee by the main stopcock.

Our stopcock was so stiff I snapped the handle off years ago. I intend to use the new one more frequently to keep it free.

I'll try this first as it is very easy to fit

I would say so yes. 9 bar is very high for a domestic supply and will stress valves. I can’t imagine that anyone needs 9 bar.

Tim

When I moved here, the internal stopcock would not turn off completely and the only way I could work on the pumbing was to shut it off as tightly as possible, disconnect the washing machine cold feed and leave it running the leakage out of the kitchen door.

I have never been able to find the external stopcock, but there was a leak under the pavement some years later and United Utilties had to dig it up.

They fitted new stopcocks (for myself and my neighbours) and access covers at the site of the leak, so I can only assume that the council had at some point re-flagged the pavement and covered out stopcocks over.

As soon as we had a usable external stopcock, I replaced the internal one. Taking the opportunity to move it from a very difficult to access position behind the washing machine to inside the gas cupboard, under the stairs.

It's probably very good for watering all of a long garden while sitting in one location :)

Tim

About every 10 years or so I strip mine, clean it, then smear some silicone grease on all relevant parts. Also operate it a bit when I remember...OK, back now...and have it open about 2 - 3 turns. Even when fitting a new one (did one where everything had to be ready and all unions checked to see if they'd undo -the tap outside cut off a block of flats!) I 'overhaul' it first.

After you turn it fully on turn it back by a quarter turn. This gives scope of wiggling it both ways when it gets stiff again.