Well pump irrigation psi/flow question

Discussion in 'Irrigation' started by country kid, May 30, 2012.

  1. country kid

    country kid LawnSite Member
    Messages: 48

    I would like to up the pressure at a well job that we just installed.

    Details are as follows
    5-6 heads per zone. 7 zones - All RB5004 rotors.
    3/4" poly split with 1".

    Each zone is matched to 14 gpm with nozzles. This keeps the pump from cycling.
    At the pressure tank, the psi gauge holds at 57 psi without cycling.

    If i nozzle the zones to 12gm, the pump will cycle every 3 minutes because it climbs to 60 psi because the cutoff is set to 60/40

    My question is.
    Can I up the cutout pressure on the pressure switch to stop at 70 or 75psi
    , then nozzle the zones to be 12gpm and making the gauge hold at 66 or something?
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    Just raise the cutoff to 70 psi and work from there - 70 psi used to be the max, based on range of adjustibility of switches, and the old standard of 75 psi tank ratings (with 5 psi safety margin, in case the pressure gauge was inaccurate)
  3. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,174

    It's amazing how many pump houses I've walked into where the gauge was defective. I finally goaded my pump guys to install glycerin-filled gauges.
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    I would give my own brand-new gauges about 5 psi leeway, just based on the usual gauge specs.

    Also, note this specific advice is based on the existing cutout being 60 psi - raising the cutoff pressure without first draining the tank and raising its air charge is piker-ish, but a 10 psi bump is okay - a big increase in cutoff pressure should always be prefaced by adding to the air charge
  5. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,226

    I've had some 100 and 150 psi gauges, that when spiked over their top end, were never the same again. I now try to get 200 psi gauges, since we have city water pressures exceeding 150 psi quite often.
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    I think I've installed some 300 psi gauges.
  7. Mike Leary

    Mike Leary LawnSite Fanatic
    Messages: 23,174

  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    I was always a US Gauge buyer, in part because I would need their 30 psi gauge to replace the frozen ones in the Toro flow&pressure gauge set.
  9. Felco #2

    Felco #2 LawnSite Member
    Messages: 41

    Is the well for irrigation only? If so, another option may be a smaller tank.
  10. greenmonster304

    greenmonster304 LawnSite Gold Member
    Messages: 3,690

    Why? That would make it cycle more often.
    Posted via Mobile Device

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