PRV help

Discussion in 'Irrigation' started by Without A Drought, Nov 14, 2013.

  1. Without A Drought

    Without A Drought LawnSite Senior Member
    Posts: 999

    We're starting a new install soon with 115 lbs. static. 2" mainline off HDPE through an RPZ into PVC.

    i've looked at watts, wilkins, and febco. and dont see any major differences besides price.

    Anyone have any preferences?
     
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,323

    I'd avoid Watts because I think they still use a non-stainless-steel spring, although that may be only for the 25A model you see in homes. I've used Wilkins BR-4 to get the high-end pressure capability missing in many standard PRVs (they may have new model numbers now, on account of the lead-free plumbing rules as of next year)
     
  3. Without A Drought

    Without A Drought LawnSite Senior Member
    Posts: 999

    central recommended the wilkins. is also cheaper than watts
     
  4. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Never seen a Febco PRV. I see more Watts fail than I do the Wilkins.
     
  5. Without A Drought

    Without A Drought LawnSite Senior Member
    Posts: 999

    wilkins it will be then.

    thanks for the help guys.

    this new job is gonna be fun, it's an apartment complex, 9 buildings. building on a brown site, so there is a clay cap about 14 inches down.
     
  6. irritation

    irritation LawnSite Gold Member
    Posts: 3,221

    You may not need a prv, don't restrict what's available and no need to dig below 14" unless it's for the tap.
     
  7. Without A Drought

    Without A Drought LawnSite Senior Member
    Posts: 999

    definitely need the prv

    and we won't be going below that depth, but normally i like to put a 2" main around 18 inches. make pulling lateral less worrisome.
     
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,323

    A possible alternative to a standard PRV would be a pressure-regulating master valve. An issue with all PRVs is their insertion loss when the regulation point is not a minimum difference from the static pressure. It can go up significantly.

    With a Wilkins, I remember performance charts that didn't make it absolutely clear that the curves only applied if the set point was at least 50 psi lower than the inlet pressure. On 115 psi static, that means you'd regulate to 65 psi tops, then lower that with your RPZ. That brings you down to about 50 psi at your source.

    With a Master Valve as the regulator, it can come after the RPZ, and knock down the 100 psi (after the RPZ loss) to 80 psi, and give you superior flow in the bargain.
     
  9. irritation

    irritation LawnSite Gold Member
    Posts: 3,221

    I don't know why, 115 on main and valves is not a problem. You certainty won't have that at the heads if designed properly.
     
  10. Without A Drought

    Without A Drought LawnSite Senior Member
    Posts: 999

    MV may be an option. i'm generally not a fan of them.
    ill do some more research and get back.
     

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