low pressure/volume

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by kwangtzu, Aug 21, 2005.

  1. kwangtzu

    kwangtzu New Member

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    Location:
    Indy
    I am hoping to do a master bath remodel which would include dual rainfall showerheads. John Bridge forum has been very helpful with tile issues, but I have a plumbing concern.

    We have city water in a 100 year-old neighborhood. The water pressure at the hose bib is only 42psi and I will end up with 31 fixture units. We have 3/4" copper pipe to and from the meter that is probably ten years old.

    Is there a way to get better pressure/volume out of this system? I was thinking to increase the pipe diameter from the meter, but with 3/4 coming in it doesn't seem that it would help. Is some sort of pressure tank an option?

    Thanks,

    Jerry
  2. Gary Swart

    Gary Swart In the Trades

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    It would help some to increase the size from the meter. A larger meter and larger pipe would help more. Your pressure is minimal, but I don't think there is any way to increase it...perhaps one of the pros will have an idea on that.
  3. Gary Slusser

    Gary Slusser That's all folks!

    About the only choice, but a good one, is a storage tank and booster pump. The storage tank would be atmospheric controlled by a float switch controlling a solenoid valve to turn on the 'city' water into the tank when needed. Then the booster pump controlled by a pressure switch and float switch in the tank to prevent the pump from running dry. Otherwise, the city water may not flow enough to feed a booster pump alone. The tank should be like a 100 gallons and easily cleaned.

    Gary
    Quality Water Associates
  4. kwangtzu

    kwangtzu New Member

    Messages:
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    Location:
    Indy
    Great, thanks for the input guys. I'll look into a storage tank and booster. :)

    If I get the pressure up that way, I suppose that the 3/4 copper through the house will be sufficient?

    Jerry
  5. kwangtzu

    kwangtzu New Member

    Messages:
    8
    Location:
    Indy
    one more question

    How many GPM should I be looking for on a booster pump?

    Thanks,

    Jerry
  6. Gary Slusser

    Gary Slusser That's all folks!

    You size a pump by the gpm needed at the elevation to the highest fixture from the pump and the pressure you want, then you select the hp to do the job. If this were mine, I'd probably look into a 1/2 hp 13 gpm, or 3/4 hp 15 gpm, SS submersible in the storage tank and a pressure tank and switch outside the tank with a constant pressure valve on the tank tee. You'll have to look at pump curves to find the gpm at your 'head'.

    And that 13 & 15 gpm isn't the max gpm the pump will produce sitting in the basement.

    Gary
    Quality Water Associates
  7. kwangtzu

    kwangtzu New Member

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    Location:
    Indy
    why submersible?

    Is that just to ensure proper cooling, hence longer life? I'm only seeing well pumps in the submersible variety. I guess a storage tank would be a "shallow" well?

    The only pumps I see offered as "municiple supply" boosters are this type:

    http://www.wwpp.us/grundfos/mq-pump.shtml and:

    http://www.daveyusa.com/hsinfo.html

    Are these recommended due to ease of installation? Seems that they would only need a storage tank since they have small pressure tanks built in and are made to supply volume on demand. They also seem a bit cheaper if I have gotten the total system requirements right.

    I appreciate the advice.

    Jerry
  8. Gary Slusser

    Gary Slusser That's all folks!

    I don't follow the proper cooliing part... I suggested a submersible becasue they give better service than any other type pump. You'll usually spend less than by buying a "booster pump" and a sub will be quieter and doesn't take up any space and on average they last longer. And yes, they are a well pump.

    Gary
    Quality Water Associates
  9. kwangtzu

    kwangtzu New Member

    Messages:
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    Location:
    Indy
    understood

    The cooling issue is brought up in relation to the non-sub pumps because both motors rely on the water passing through/around to regulate temps. Apparently there was an issue with older non-subs cylcing off too quickly and thus burning out motors because they didn't circulate enough water to make up for the heat of start-up.

    Quiet and space are issues I understand, though the longevity issue is highest on my list. Thanks again.

    Take care,

    Jerry
  10. plumber1

    plumber1 Plumber

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    Location:
    Florida
    water volume

    Are you talking about city water or a well?

    Why not look at the old water service and fix that?
  11. kwangtzu

    kwangtzu New Member

    Messages:
    8
    Location:
    Indy
    City water. Since the pipe running into the basement looks like new 3/4" copper, I don't know what to look at.

    Also, all my neighbors have low pressure---below 50psi at the bib---we live in an old neighborhood. The electric service is underpowered enough that my AC unit needs a hard-start kit even though I have a 200 amp box, and the phone lines don't support DSL.

    The house utilities were all redone about ten years ago, so I don't think the problem is on my side. Any advice on possible remedies would be welcomed, though.

    Jerry
  12. plumber1

    plumber1 Plumber

    Messages:
    1,423
    Location:
    Florida
    pressure/volume

    You could put a gauge somewhere on your system and see what PRESSURE you have. If you don't have VOLUME, then the line coming into the house is your problem. Put a gauge on a hose bib and turn the hose bib on. have someone open a faucet and see how much PRESSURE drop there is. The more of a drop means a greater lack of volume. It's not an exact science, but there shouldn't be a large pressure drop. If the drop is great then start with the pipe coming in from the street.
    Yes, you could look at putting a 100 gal. tank and suck the water out of the city service with a small well pump.
    I wouldn't use a booster pump, A submersible pump wont work either.
    But I would consider a small well pump that I could get 60 or so lbs. pressure from. But the right way is to be SURE WHICH way to go.
  13. Gary Slusser

    Gary Slusser That's all folks!

    Only submersible pump motors are cooled with with. A jet or centrifical pup motor is air cooled.

    plumber1. Possibly you forgot that he said: "We have city water in a 100 year-old neighborhood. The water pressure at the hose bib is only 42psi and I will end up with 31 fixture units. We have 3/4" copper pipe to and from the meter that is probably ten years old.".

    A pump can't suck water from the city water line and then increase the volume if the flow volume and pressure is insufficient for the house now, and increasing the ID of the pipe doesn't increase pressure. That's why the storage tank is required.

    The present service line fills the tank and is controlled by a normally closed solenoid valve which is controlled by a float switch. The pump is controlled by a pressure switch and the power to the switch is controlled by a float switch to prevent running the pump dry. The choice of pump is either a shallow well jet or (not suggested) a centrifical OR submersible. A submersible pump in the tank is the best solution all around and will, if bought right, cost less than a Davey etc..

    Gary
    Quality Water Associates
  14. plumber1

    plumber1 Plumber

    Messages:
    1,423
    Location:
    Florida
    pressure

    Hi Gary. You misunderstood me or I probably didn't say what I ment properly.
    Don't spell too well either.
    We did the pump thing years ago, because of an elevation thing, and it worked quite well.
    When I think of a submersible pump I think of a 4" well.
    I did say you could use a 100 gal tank with a shallow well pump.
    With storage capacity, you will gain volume.
    That's why it seems that he should really consider checking the water service as the problem.
    I did say that the water coming to the house might be the problem..

    Thanks Gary
  15. Gary Slusser

    Gary Slusser That's all folks!

    No problem. Yes the submersible would be a 4" well pump like a 1/2 hp 13 gpm and preferably 230 vac but could be 120.

    Gary
    Quality Water Associates

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