Time for a PRV

Discussion in 'Irrigation' started by cjohn2000, Apr 29, 2014.

  1. cjohn2000

    cjohn2000 LawnSite Senior Member
    Messages: 570

    Started a site today, small apartment complex 1.5 or 2" dcva in basement mechanical room. Most zones are 10-25 gpm. Noticed alot of 6" popups cracked along the sides and one the top of the body cap and wiper seal had blown out, leavin just a threaded nut behind and every time I turned a zone back on it seemed more heads were cracked. Finally I took a dynamic pressure reading on a zone and I got 98psi! PPV definitely needs to be installed asap. Oh and I found this gem, 2" popup installed in a 4" body with the remains of a riser in the base:hammerhead:

  2. irritation

    irritation LawnSite Gold Member
    Messages: 3,594

    Freeze damage, never use the side inlet.
  3. cjohn2000

    cjohn2000 LawnSite Senior Member
    Messages: 570

    Maybe, all the heads I ended up replacing were bottom inlet. With 98psi everytime that valve snapped on it seemed to blow another head out
  4. irritation

    irritation LawnSite Gold Member
    Messages: 3,594

    I have one area that has crazy high city water pressure. The 1800's last but it kills the PGP's.
  5. cjohn2000

    cjohn2000 LawnSite Senior Member
    Messages: 570

    Im not usually a big fan of cutting in PRV's at the POC, but the pressure is tearing this system apart.
  6. Without A Drought

    Without A Drought LawnSite Bronze Member
    Messages: 1,087

    my guess is freeze damage. those heads can handle 100psi. not ideal, but they can hold up to that. freezing, not so much.
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,758

    Sight unseen, a standard PRV is less of a good choice than a pressure regulating master valve, on account of the standard PRV having much higher pressure losses.
  8. cjohn2000

    cjohn2000 LawnSite Senior Member
    Messages: 570

    Hadn't thought about that, would be cheaper too, parts wise.
  9. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,132

    You do not want cut in a PRV. I have had to bypass a lot of PRVs. They restrict flow unless sized way above pipe size. Especially if they were not necessary in the first place. Under 100 PSI, not needed, nor desirable. Most valves and irrigation equipment are capable of handling up to that. If you have to, test static pressure, figure out your system gallonage, then see which PRV will be able to supply the gallonage called for under those conditions. On a 2" main line, that might mean a 21/2" or 3" PRV. I say this because many systems in high pressure areas were designed to make use of the pressure and volume. In an ideal world, they would be designed for what the equipment specs call for. 1800 pop ups do not need a lot of pressure, but they demand high volume.
  10. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Messages: 6,201

    Thats a heavy push!

    anything over 60 psi and those pgp's will have an extreme half life.
    Sh!t head.

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