Irrigation Trouble Shooting

Discussion in 'Irrigation' started by Crimson Lawn, May 20, 2014.

  1. Crimson Lawn

    Crimson Lawn LawnSite Senior Member
    Posts: 319

    Was able to make it out there to continue work. Owner had more pressing things for me to do.

    I jumped the BF from the meter to the main line, also skipping MV. Still weak pressure. Even isolated to just one zone, same result.
    Found the main control valve, it was filled with water. Bailed and bailed, could not find a primary shut off for the irrigation meter.
    No leaks, Turn the meter on and off a few times to make sure it was open all the way, checked the static pressure, 80 psi.
    Whats left for to do is check flow pressure and have city come out and check their meter and to see if they can find the tap, off the main to the irrigation meter.
    Am I missing anything else?

    Thank You everyone.
  2. AI Inc

    AI Inc LawnSite Fanatic
    Posts: 25,396

    Did you you check the screen filters at both ends ( sometimes only one end ) of the meter?
  3. Crimson Lawn

    Crimson Lawn LawnSite Senior Member
    Posts: 319

    City came out and did a pressure check and flow test with pressure.
    17.44 GPM with a 48 PSI. Meter was clear. No curb stops or other valves for that meter.
    Called the local JDL searching for other clues. Cut mainline and isolated water flow to only one zone. Still weak. Then a good call came in from a friend with same problem. The RB PGA Valve's on his system was the culprit. Will pick up 2 100 pga's tommorrow and replace MV and zone 1 valve's, if that cures the problem then I will isolate zone by zone to replace the one's that need it.
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,722

    Are you running zone valves entirely manually, by way of bleed screws, no controller involved? That's a quick way to bypass solenoid and some diaphragm issues.
  5. gradioc

    gradioc LawnSite Member
    Posts: 61

    I've seen the beginnings of a problem with previously dependable valves like my favorite, the Toro 250 series, but I kinda knew what I was looking at because of the number of Rainbird EV's I've dealt with. The port through the diaphram to the control chamber is becoming enlarged. The port between the control chamber and the solenoid chamber or (usually) the port out of the solenoid chamber to downstream, cannot dump enough water to let the valve fully open. Trying to remember if the PGA has an external bleed as well as the 1/4 turn solenoid option. If it does, dump water and see what happens. If it pops up and runs right, you need a diaphram. I think you said you bypassed the MV, but that's the most likely place for it to happen. I think the introduction of chloramine is a factor.
  6. cjohn2000

    cjohn2000 LawnSite Senior Member
    Posts: 554

    You may run into a issue if the valves installed are the old PGA, new PGA guts will not swap into the old ones. We see a lot of pressure problems relating to old *WM with worn out diaphragms. Usually I can hear when a valve is having a hard time opening due to a worn diaphragm, usually a hissing sound.
  7. Crimson Lawn

    Crimson Lawn LawnSite Senior Member
    Posts: 319

    Well, back to troubleshooting.
    I replaced the MV and zone 1 valves. Just top and guts. That recommendation came via RB and JDL. The main line is still cut at the tee, only feeding zone 1. Same issue. Checked pressure, running at 56 psi, meter shows 10.76 gpm. Zone 1 has 12 4" pop ups, 4 at 180 open, 4 at 90 open and 4 that vary but nothing over 180 open.
    I was told to by pass the meter with a jumper and try that. There seems to be a restriction somewhere. If it is not the meter the next thing is to dig up the pvc 3/4 ball valve before the BF, inspect.
    This is keeping me on my toes. Main line is running underneath busy hwy where it is tied into a 16" main.
    I wondering how long owner will put up with my trouble shooting? Huge customer!!
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,722

    We haven't yet read just how the backflow preventer (make and model, please) was ruled out as a possible problem.
  9. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,988

    Good point, it happened to me once. :cry:
  10. Check for a pressure reducer on the main line, it could be in a box or not. Also check pressure via #1 test port on the backflow preventer.

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