Slow leak out of pop up head

Discussion in 'Irrigation' started by LawnsharkMB, Sep 16, 2013.

  1. LawnsharkMB

    LawnsharkMB LawnSite Senior Member
    Posts: 581

    I've seen this a few times. It's always a head that is at the front of the yard near the road at the bottom of a slope. I've always assumed this was water draining out of the system.

    Today a guy stopped me and said that when he turns the main irrigation valve off the water stops leaking out and if he doesn't it will not stop leaking. So I'm guessing the control valve is not closing all the way.

    Can this be fixed or does the control valve need to be replaced? Or is it something else?

    I don't know if this makes a difference but the head is about 10 ft directly below the main irrigation valve. None of the other heads leak in that zone but the one near the road.
     
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,910

    Fix the zone valve.
     
  3. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,774

    Check the valve, but I'd bet there are no low-drain check valves in the the drop. 10" is a lot of drop, and even a RB SAM will not hold that. Only the Hunter LDC will hold that much, but then friction loss rears it's ugly head.
     
  4. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,774

     
  5. ArTurf

    ArTurf LawnSite Gold Member
    Male, from Ark
    Posts: 3,412

    From what you have said it is prob both; seeping valve and low head drainage.

    The valve might can be fixed, depending. May be as simple as a small piece of debris preventing it from closing. But can be more complicated.

    The low head drainage. I would put put check valve heads on the enire zone which would not totally cure but would help.
     
  6. LawnsharkMB

    LawnsharkMB LawnSite Senior Member
    Posts: 581

    Thanks for the responses.

    One more thing. The homeowner said he cut the main irrigation valve off because they were putting a patio in and he needed to move a head. Of course he didn't need to do this but he did and when he cut it back on the leaking started. He claims it has never done this before.
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  7. 1idejim

    1idejim LawnSite Fanatic
    Posts: 9,075

    If any check valve holds 10 feet, the pressure on the lowest head is holding 4.33 psi.
    Less as you go up the slope.

    Lets say that your supply is 40 psi.

    If the valve is weeping then the water has 40 psi behind it.

    Once the lateral is full the water will still have 40 psi pushing it.

    What would the pressure at the bottom head be?
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  8. LawnsharkMB

    LawnsharkMB LawnSite Senior Member
    Posts: 581

    I should have explained it better. It's not 10 feet of slope. I was just saying the head is close to the main valve. It's only like 6" of slope but it is the lowest head.
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  9. ArTurf

    ArTurf LawnSite Gold Member
    Male, from Ark
    Posts: 3,412

    Maybe I didn't explain it right but I was not suggesting the check heads would fix the seeping valve. Just the low head drainage part AFTER the seeping valve was fixed. From my experience even if say there is 10' feet of elevation drop and the heads are rated at 6' they will stop draining out once the static pressure drops below a certain level. Not perfect but far less drain out than heads without checks.
     
  10. 1idejim

    1idejim LawnSite Fanatic
    Posts: 9,075

    The HO prolly used the flow control and turned it down tight (tight is right) and wrecked the diaphragm.

    just saying :)
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