Pressure regulators & old house - one tap on and flow drops on another?

Discussion in 'Plumbers' Talk' started by ajohn, Jul 13, 2018.

  1. ajohn

    ajohn Member

    Do pressure regulators help with this problem? I have heard about ball valves being used on all taps to regulate flow to lessen this problem but it's a messy solution. I can't expect a perfect solution, several bedroom sinks and 2 bathrooms etc but all aren't used at the same time so any improvement would help. One tap going on can cause another to just dribble at the moment.

    We use a type of instant water heating as well. So should I provide full flow to the inlet of that and a pressure reducer on the output and also on the cold to the rest of the house?

    I am changing some of the pipework so wonder if more changes would help with this problem.

    The house was built in 1911 and has had a fair bit of pipe work changes in the 70's. All of it by the look of things. My parents house was built in the mid 50's and didn't have this problem, I can remember my father saying that there was a bit more science in this area compared with older methods. No pressure regulators though and hot and cold water tanks. ;) Wish I had examined the pipework.

  2. Heat

    Heat Well-Known Member

    Hi John. What type of water system do you have exactly?
    If it is all mains fed you firstly need to have checked that the stopcock is full on and also that there isn’t a restrictive valve fitted somewhere.
    Your taps flow are best controlled by restrictive aerators on the end of the tap spout. If you find any difficult to do that, then a little flow regulator can be installed in the pipes coming up to the tap. (They are only a coin like disc and can be got for various flow rates in litres per min. Should only cost a few pound each)
  3. The Teach

    The Teach Well-Known Member

    ajohn,have you measured the incoming cold mains water flow & pressure ? Its important to know what is available ;)

    flow regulators can be strategically placed on any system to ensure best water performance where performance is required ie showering.

    Happy plumbing :)
  4. ajohn

    ajohn Member

    Hot water is via an indirect heat store fed from the mains - maybe badly at the moment. Cold direct mains pressure, The tanks probably went in the 70's. There is a flow restricter in the heat store so have to live with that. Also the heat of the water that comes out of it. The capacity would be too low if I turned it down.

    The bad point about the feed to the heat store is that most of the cold taps run of the pipe feeding it before it gets there. That's down to the person that installed the central heating, ;) I wouldn't have done that. Might have helped might not. That's why I wonder about a pressure reducer. Repiping isn't too bad as just have to reroute the mains feed and then use what's left of the old one for the supply to the taps via a reducer. It's then pretty simple to add another one for hot. I need to fit a thermostatic mixer valve as well since the kitchen akquired 1/4 turn taps. There isn't a pressure differential problem with that even if just one pressure regulator is fitted. LOL - I do see what these may not help - higher flow tap opens and runs at say 3 bar - another opens so regulator lets more flow through at 3 bar so both get 3 bar and flow accordingly - sounds great in theory - but - and not too bad price wise.

    Looked at my usual source of parts - here and the other one. Tap end restricters yes but no disks. Some 70's taps last a hell of a long time and are still going strong. A change there would need new sinks in places as well, separate hot and cold taps. The hot water on those can get too hot as well.
  5. ajohn

    ajohn Member

    As I live in older B'ham I am pretty sure there is more than adequate pressure. The problem when some one buys a house and has sinks fitted all over the place is there isn't a strategic place other on the feed to the actual taps really. Where I have done work and can ball valves are fitted. Fitting them to some sinks though is tricky. The other old pipe threads I started allow me to control a bath and one sink flow problems but they are tricky to set. I've also fitted them to the new kitchen taps. Those get hot water so quickly now that there is serious risk of scalding and also the tap itself gets way to hot to touch. Trying to mix via the tap isn't on. The pipes to the old kitchen tap ran through a trench in a solid floor and and are buried in the wall right up to the tap connector. There is another with pipes in the wall as well. :) The people must have spent a fortune "upgrading". I think flow was regulated by 2 gate valves, one feeding all of the ground floor and the other the rest. Too many problems with the ground floor feed so that's gone now. The house was owned by 2 ladies jointly and they lived totally separately so the old set up worked for them as each could turn a tap on without causing problems for the other - so flow is fine really.

  6. Heat

    Heat Well-Known Member

    If by ball-valves you mean the ordinary isolating valves with slotted screw, then they are not much good for closing down flow properly. They will create a noise once you turn them nearly full off. In fact I refuse to install them due to their inferior quality (and restrictive flow if on gravity systems). I use full flow iso valves and they have proper seals inside them. Still no good for proper flow reduction though.
    The only thing that works properly is flow reducers. Simply turning a valve down at a tap just means you have a tiny gap for water to flow and this creates the water roar noise. So you turn the valve slightly more open and defeat the objective.
    The pressure reducing valves are not ideal for restricting flow as they will still maintain flow, albeit at the pressure it regulates to. Pressure and flow rates are different things
  7. Heat

    Heat Well-Known Member

    Look up online - Deva 4 litre flow restrictors, to see the sort I meant.
    Those particular type replace the seal washers in flexi hoses, but you can buy similar that go inside a fitting
  8. ajohn

    ajohn Member

    I have used ball valves on the new kitchen taps, mainly for isolation but at around 2/3 open the knock back the flow from the tap a touch. I don't think it's really feasible to use them to make sure all taps run but they can help a bit. Main thing I have found with them is that plated is best as plain brass can corrode and seize up. One the central heating plumber installed has.

    Where I have used full bore ones I found the same type with a handle on were much cheaper than the slotted screw types. They are all still ball valves.

    I have looked for the in fitting flow restrictors. So far have only found ones that also come with a fitting that looks like a plated ball valve.

    Pressure regulating valves are never perfect as the pressure will vary with flow but if that way works the taps themselves form the restriction - one tap gets say 3 bar and gives what ever flow that produces through it, another tap is opened and the pressure drops so the valve tries to restore the pressure to 3 bar. If it succeeds that tap gets 3 bar as well and to do that the flow has to increase. There is a bit about them here

    :) Sounds great but I suspect ones that do the job well are rather expensive. They certainly are for use on other fluids. Believe it or not air or any gas is a fluid so the same techniques are used. They are compressible though which will make a difference so ones that have water running through them are unlikely to work so well.


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