master control valve; several questions

Discussion in 'Irrigation' started by silvercvic, Nov 2, 2006.

  1. silvercvic

    silvercvic LawnSite Member
    Messages: 41

    What is the purpose of the master control valve besides it shutting down the entire sprinkler system? I've read in a book its not needed but a great insurance for conserving water. I just confused because it mentioned was an automatic valve, at first, then a gate valve later (but not the main shutoff).

    Does it have a place to be wired in a controller (Hunter Pro-C)? Does open each time a zone valve is open? What happens if a zone valve opens and the main control doesn't?

    i'm at the point in my installation where I have installed most of the PVC pipes underground, wired up 3 zones in a valve box (front); teed off PVC to the backyard.

    I'm about to wire up the backyard (3 zones), hook up the RPZ and connect that to the front valves, I'm wondering if I need to -or- should connect 1 more valve right after the RPZ to be the main control valve?

    Any suggestions?!?
  2. Mjtrole

    Mjtrole LawnSite Member
    Messages: 226

    We don't use masters, just one more wire connection, pipe connection and valve to have problems with down the road, yes the pro-c should have a master terminal, if not wire it up to the pump terminal.
  3. YardPro

    YardPro LawnSite Gold Member
    Messages: 3,570

    it is a good idea to use one.

    yes the pro c has a terminal for it. it is the pump/ MV terminal. it is the first one above the common.

    a master valve should be installed where you tap into the main line. What it does is to limit the time that the main line is pressurized. The main is only under pressure when a zone is running. This reduces the chance for a leak in the main.

    it is more important when you are doing in line valves, or when the main is a long way from the tap in to the manifold.
  4. londonrain

    londonrain LawnSite Silver Member
    Messages: 2,129

    I just installed a 1" Rain Bird PEB today as a master valve on a job I am working on. All other 8 valves are 1" Hunter PGV valves.
  5. jerryrwm

    jerryrwm LawnSite Bronze Member
    Messages: 1,274

    Don't trust the Hunter valve as a MV?
  6. londonrain

    londonrain LawnSite Silver Member
    Messages: 2,129

    I have always used a PEB as my master valve. I guess I am just set in my ways....
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,751

    I only use a master valve when I have a poly main line, and don't want it under 24/7 pressure. For a manifold of valves near the house, I'd rather spend the master-valve money for zone valves with flow controls.
  8. silvercvic

    silvercvic LawnSite Member
    Messages: 41

    Well, the RPZ comes out of the house, since I am teeing the line from in the basement and coming out of the house, should I have the MV before or after the RPZ (take some pressure of the BFD as well??)?

    Asides from that the RPZ is only about 2 ft away from the front manifold and about 80ft from the back area manifold zone.

    Also is it just any valve or does it have to be a Rainbird PEB (or similar), my current manifold setup consists of Rainbird Jartops?
  9. londonrain

    londonrain LawnSite Silver Member
    Messages: 2,129

    Look at it like a safety valve in which two valves must open for one zone to open. It can be any valve but I use the PEB since it is a great valve but pricey. With a master valve the likely hood of a zone valve running for days on end if you have a zone stick open while out of town. I especially use master valves at the end of culdesac since all the trash in the mains gets flushed to the end of the line which is a culdesac in my area.

    PROFESSORRAIN LawnSite Member
    Messages: 246

    Look at it like this mv don't come on NOTHING GETS WATER

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