Looped system

Discussion in 'Irrigation' started by h20 guy, Mar 20, 2008.

  1. h20 guy

    h20 guy LawnSite Member
    Posts: 50

    Picked up maintenance on a commercial site with a looped system. The system is fed from each end from a 1" water meter and a 1/2 hp booster pump. One side has 12 zones and the other side has 9 zones, a little confused, won't water be demanded from both ends when the 1st zone is activated, or does the booster pump not running stop the flow of water from that end. any help appreciated.
     
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 22,073

    Looped mains have been a subject of disagreement for years: the reduction of friction
    loss & hammer is a plus on a loop..my question would be: does the pump activate for
    both p.o.c.s, & how is the pump activated: pump-start relay from the clock, on demand?
    Glad to help, but need some more info..mite want to check the psi @ both p.o.c.s with
    & without the pump. The bottom line, if it works, don't fool with it, tho I would like to
    know the mechanics of the system were I maintaining it. Do you know who put the
    pump in? Do you have two backflow assemblies? :)
     
  3. dougaustreim

    dougaustreim LawnSite Senior Member
    Posts: 488

    One of the biggest problems I have seen with loop systems has been with blowout. You have to make sure that water is blown out throroughly. Since the air can loop either way, water can remain one one side of the loop. The best thing to do is to install isolation valves in the middle of the loop with a drain in between and blow out half at a time.

    Doug
    Austreim Landscaping
     
  4. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 22,073

    With a compressor,you should be able to drain both sides of the main thru the zone valves,
    tho you are on the money about iso valves; I wonder if our friend got a
    set of plans?
     
  5. Rotor_Tool

    Rotor_Tool LawnSite Senior Member
    Posts: 349

    For the spelling nazi...

    mite as in ear mite is correct.

    mite as in might want to check the PSI is incorrect.

    Man, that feels good and it gets the post count up. No wonder you are over 4K.
     
  6. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 22,073

    And, you are? Big 145 don't count yet.
     
  7. TennTexan

    TennTexan LawnSite Member
    Posts: 38

    I mite want to get in on this, altheaux I guess I won't.

    Jeff
     
  8. h20 guy

    h20 guy LawnSite Member
    Posts: 50

    Mike, thanks for the reply back, each controller is wired to a p.s.r., each p.o.c. has a 1" Febco p.v.b. As far as a As-Built being available of course none of the current owners have a clue to who installed the sytem. The whole set-up seems to have been a after-thought after the sytem was installed and the installer was forced to add the 2 booster pumps to get the added pressure necessary to run the system. Will the 1 p.o.c. still flow water from that meter even though the other controller has activated the booster pump and vice-versa? Thanks for any suggestions.
     
  9. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 22,073

    Yes, but only at the static pressure from the supply, actually less because
    of the friction loss thru the booster that is not operating. I would not worry
    about it unless you're trying to squeeze a few more psi into the system.
    A thought...if you have spare zones & programs on the clocks, a "dummy"
    start time could be programmed to get both pumps running simultaneously. :)
     
  10. h20 guy

    h20 guy LawnSite Member
    Posts: 50

    Thanks Mike, appreciate your thoughts. Could you explain a little further about your "Dummy" start time. I am going to test the system when I start it up in a couple of weeks without the booster pumps just to see what the performance is with out them operating.
     

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