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Booster pump with expansion tank

pipers
pipers Member Posts: 21
Difference if any between a well tank and expansion tank and a cushion tech really interested in cushion  tank which is what was recommended for my booster pump

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    Rated pressure, materials, and capacity. They have very different purposes. The "well" tank is there to control the well pump cycles. Its capacity is fairly large, and the sizing is set so the well pump doesn't cycle on an off too frequently. The expansion tank is a term usually used for heating systems and domestic hot water lines which have a check valve on them somewhere, and is smaller -- but the materials can withstand high temperature water. You may find different tanks for heating use, with a relatively low working pressure, and domestic hot water, with a considerably higher working pressure but smaller volume. A cushion tank for a booster can be quite small, since all you are trying to do with it is to reduce pressure spikes when the pump turns on -- but it needs to have a working pressure rating at least equal to the shutoff pressure of the booster pump and supply combination.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    pipersSteve Thompson (Taco)
  • leonz
    leonz Member Posts: 1,096
    edited July 2022
    Whoa!!!!!, hold on here; what do you mean a cushion tech????????????????????????????????????????????????????

    I want you to go here first before you open your wallet or write check.


    www.waterdefense .org/water/well/expansion-tank-vs- pressure-tank/

    =================================================================

    It depends on your wallet and how much you want to spend for more potable water storage.

    Let us start at the beginning with some questions directed to you;
    ------------------------------------------------------------------------------------------

    This first question is the most important one you need to answer right now:

    Was he smiling when he suggested a bladder tank?

    Is your home water supply a municipal water supply with no elevated storage tank nearby to provide additional water pressure?

    Is the pressure regulator in the home and is there a water pressure gauge attached to the body of the pressure regulator?

    ------------------------------------------------------------------------------------------

    A cushioned water storage tank is a galvanized water tank that has an air charge that provides system pressure.

    A bladder tank has a rubber flap that expands to accept water and contracts to push water into the homes water piping with a smaller air charge volume.

    The bladder tank has a very large tapping in its base to accept a short nipple, elbow and very long bronze Tee with tapping's for a pressure switch, pressure gauge and additional tappings that could be used for a chlorine injector etc. The unused tappings would be plugged before use.

    The bronze tee inlet would be connected to the booster pumps pressure side and the booster pump 20-40 pressure switch is wired through the limit switch contacts to control the booster pumps operation.


    =================================================================


    The cushion tank has a limit switch threaded into the tanks large upper tapping where the limit switch arm attached to the rubber float that rides up and down on the water in the tank.

    The cushion tank is connected to the water supply with small bronze tee which has a pressure gauge threaded into one of the tapping's and the pressure switch threaded into one of the tapping's.
    The float switch adjustment controls how much water is in the tank and the water pressure as an air charge is pushed into the snifter valve to pre-charge the tank.

    A very large galvanized cushion tank with a 40 PSIG pre-charge pressure will provide you with a great deal of water and many decades of service before the float switch or the pressure switch needs to be replaced and the tank must be pressurized again using the snifter valve.

    Bladder tanks in potable water service do not have a long service life and can be much more expensive to purchase and install than an air cushioned tank; been there, done this, should have installed a cushion tank.

    =================================================================

    If you have room for a large unpressurised storage tank in the basement (if you have a basement) you can
    use it for storage and use a simple limit float valve with a float ball to control the water level in the tank and plumb the booster pump through the top of the tank with a foot valve on the suction side of the booster pump leaving the pressure settings and other plumbing as is.
  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    Good thoughts, @leonz . I was assuming -- perhaps naively -- that the OP was talking about an in-line booster pump controlled by its own pressure switch -- and sometimes a separate on/off control -- to get higher pressure for, for instance, some types of sprinkler systems...

    What are we really talking about here, @pipers ?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • leonz
    leonz Member Posts: 1,096
    edited July 2022
    Hello Jamie,

    I guess we will be paddling in the dark on calm waters
    waiting until he responds to my questions.

  • hot_rod
    hot_rod Member Posts: 22,024
    edited July 2022
    A lot of the pressure booster pumps these days are variable speed and only need 1 gallon or less of a “cushion tank”. It depends on what you have and what type of demand and cycle lengths.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    STEVEusaPAZman
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,725
    edited July 2022
    I just got a kick out of this first line in @leonz comment.
    leonz said:

    Whoa!!!!!, hold on here; what do you mean a cushion tech????????????????????????????????????????????????????

    Was that an auto correct... or is that a reclining chair in the back of the service van with a big cushion for the Tech when he takes a lunch break?

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics