Newbie, dumb ?

Discussion in 'Irrigation' started by Stuttering Stan, Jun 24, 2005.

  1. Stuttering Stan

    Stuttering Stan LawnSite Bronze Member
    Posts: 1,504

    I am trying to get my shallow well pump going for the first time since I bought the house. I bought a 1/2 hp pump @ lowes. I cannot get it to prime. Do I have to have a pressure tank in the system?
     
  2. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    The pressure tank keeps the pump from cycling (which will prematurely wear a pump out). I would definitly add one.

    As far as it not priming, how deep is this well, is there any way to fill the siphon tube with water (how have you plumbed it?)
     
  3. jerryrwm

    jerryrwm LawnSite Bronze Member
    Posts: 1,274

    Is this a shallow well jet pump? Do you have the injector properly installed?

    Is this a centrifugal pump? Did you install a foot valve at the bottom of the stand pipe? Is it less than 21' to the static water level?
     
  4. drmiller100

    drmiller100 LawnSite Senior Member
    Posts: 562

    heck no you don't need a pressure tank. what a waste of money for an irrigation system.

    take the outlet hose off the pump. fill it with water. keep filling it until water runs out.

    you do have a foot valve on the inlet, right?????
    the foot valve goes on the opposite end of the inlet line from the pump.
     
  5. jerryrwm

    jerryrwm LawnSite Bronze Member
    Posts: 1,274

    A pressure tank on an irrigation system is best used when you can get the system balanced enough with the pressure switch settings to keep the pump from building pressure over what is required in the system thereby shutting off.

    Ideally you want the pump to switch on when the system is activated and then have the pump run continuously until the cycle is done. This will prevent short-cycling of the pump - sure cause of premature pump failure.

    Use a pump start relay to start the pump and you will eliminate the need for a pressure tank/pressure switch. The PSR is wired from the controller to the pump motor wiring harness. When the controller calls for a valve, it also sends a signal to the PSR and the pump turns on. No short-cycling, no pressure fluctuations, just a steady water supply.

    If you are going to use the well for hose bibbs around the property, then you should install a small pressure tank. But don't rely on a small tank to run the irrigation system. If you have a 20 gal pressure tank, remember that you have half or less of that water for draw-down and then the pressure switch kicks the pump on and it gets to be a real mess. Just use the tank for hose bibbs, and you'll be fine.

    And don't use the mainline for a pressure vessel. In other words, a pump and a pressure switch with no tank does not make a pressurized water system. It doesn't work worth a damn, and you can very easily burn up pump motors.
     
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,006

    For a pump that's running constantly, a pressure tank and control switch aren't necessary, but the advantages of them can be had at little cost. Most jet pumps I buy have the pressure switch already mounted, and I can add a very small pressure tank (think water heater expansion tank) which allows smooth shutoffs. A jet pump using the control switch and pressure tank will work without a pump relay, so the dollars may balance out. Having a pressure switch control the pump protects you against a zone that get stuck/clogged shut, and the pump running continuously without moving water.
     
  7. Stuttering Stan

    Stuttering Stan LawnSite Bronze Member
    Posts: 1,504

    Everything that was just said is over my head. I guess ask a favor of a local pump guy. Thanks for all the replys.
     
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,006

    Pumps are tricky. So many things can go wrong. Sometimes its best to get a pro to handle it. Not knowing Lowes, I wonder if the pump you bought there might not be taken back, with the money being used towards a more professional set-up.
     

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