Master valve BEFORE the backflow?

Discussion in 'Irrigation' started by justgeorge, Jul 24, 2006.

  1. justgeorge

    justgeorge LawnSite Senior Member
    Posts: 352

    Had a customer call me today; their backflow device was dumping water most of the day till she shut the water off. It's a reduced pressure device, which of course WILL dump water if debris or something causes it to stick open. The only solution that I can think of is putting a master valve on in front of the backflow device. Not sure if plumbing code would allow that though - are their any solenoid operated valves (maybe brass) that might meet code? If the customer is gone on vacation the backflow could dump for a week or more.

    Thanks,
    George
     
  2. NC_Irrigator

    NC_Irrigator LawnSite Bronze Member
    from NC
    Posts: 1,416

    It shouldnt dump unless theres like you say trash in the line. Usually check valve #1. Or a drop in pressure on the supply side of the device.
     
  3. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,019

    You could always install a series of Barometric Loops in the system, which would never spill. :p

    No. You don't install any master valve upstream of an RPZ. You fix the RPZ. If you have extremely high water pressure, a pressure reducer will help. On well water, you install 100 mesh filtration before the RPZ. I have also heard of installing a separate check valve upstream of the RPZ, which can interfere with the forces that can cause a relief to spill.
     
  4. justgeorge

    justgeorge LawnSite Senior Member
    Posts: 352

    I agree I have to fix the RPZ. So you're saying there is no solution to this possibility, and if it starts dumping while the customer is gone on vacation it will dump until a neighbor notices it and shuts it off at the backflow? It is city water, not well water, so in theory there shouldn't be any debris, but sh!t happens.....

    I guess if I think about it this must be an EXTREMELY rare occurance or else people would be screaming about all the wasted water when RP backflows stick open and dump?
    George
     
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,019

    Drips are more likely than total dumps. They do make 'alarm' backs for the relief section. Those would be capable of triggering an alarm, or even closing a motorized ball valve. What is the model of RPZ? How much pressure? How much flow?
     
  6. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,794

    Are Doublechecks allowed in your area? Quick and easy fix there.
     
  7. justgeorge

    justgeorge LawnSite Senior Member
    Posts: 352

    It's a Febco 860 RP, 3/4". I haven't seen it dump yet so I don't know how much it was dumping. The customer did say her sump pump was running pretty much constant, and it had never run before (house less than a year old). Backflow is next to the house so the water was running down to the foundation. I'll see how much it was dumping tomorrow when I'm there, and can also put my pressure gauge on it and see what the pressure is. Probably in the 70 lb range.
     
  8. justgeorge

    justgeorge LawnSite Senior Member
    Posts: 352

    I wish. All 3 counties that I do work in require RP devices.
     
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,019

    RP's don't have to be headaches. I had the most trouble with a Febco 825Y that always acted up when the system was opened in Spring. The high water pressure and high flow helped create an 'oscillation' when the highest-flow zone valve closed - at least until every last bit of air was bled out of the device.

    If you service the systems, it will pay to be able to deal with the RPZs you encounter. Ever dismantle a Febco 860?
     
  10. justgeorge

    justgeorge LawnSite Senior Member
    Posts: 352

    Well I have now. Found Febco's website last night; it had good pics and instructions. Took out check valve #1 and found a nice little pebble, probably 1/16" x 1/8" in size stuck in the check valve. Guess the water company's filters weren't up to snuff.

    Why wouldn't you put a valve in front of the backflow device - will that prevent the backflow from functioning correctly?

    Thanks,
    George
     

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