Flow from 1" copper............

Discussion in 'Irrigation' started by mjstef, Aug 28, 2013.

  1. S.O.Contracting

    S.O.Contracting LawnSite Member
    Posts: 186

    5 ft /sec rule applies to pvc and poly. Copper pipe is 8 ft /sec. That's what all the flow charts are based off of. He never said was size and materials his lateral lines are. 18 gpm is getting close but still safe but does lose 10 psi in friction loss.

    Velocity copper
    http://www.engineeringtoolbox.com/copper-pipes-water-velocities-d_1081.html

    Flow chart K copper
    http://www.rainbird.com/documents/turf/ref_Type K Copper Water Tube.pdf
     
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,799

    Someone is looking at at different flow chart....5 ft/sec is still the rule, I don't care what material one is using.
     
  3. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,008

    The "don't short-cycle the well" rule has absolute precedence in this situation.
     
  4. mjstef

    mjstef LawnSite Member
    Posts: 145

    Here's the deal, if I stayed with 5 feet per second I would be short cycling the well. The horse and a half pump tested yesterday puts out 23 gallons a minute. I am running at 7.5 feet per second which is well within the design parameters of what I am using. There is absolutely no water hammer when the valves shut off. There is a 10 foot piece of 1 inch copper stubed to the outside of the house and from there it goes 1 inch poly to the valve box and all laterals are 1 inch.
     
  5. Sprinkus

    Sprinkus LawnSite Silver Member
    Posts: 2,083

    Copper.org states that "The recommended maximum velocity for water in a copper tube system is 5 - 8 feet per second (fps) for cold water systems, 4 - 5 fps for hot water systems < 140º F, and 2-3 fps for hot water systems with a temperature greater than 140º F."
     
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,008

    The small problem with velocity recommendations taken as a line you must never cross, is that there seems to be no penalty for crossing those lines, at least with heavy-wall copper in conjunction with cold water.
     
  7. mjstef

    mjstef LawnSite Member
    Posts: 145

  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,008

    The odd thing I note about the system details, is that they contradict the stated aim of a minimum of trenching. I wonder how much of the acre-plus is actually being watered?
     
  9. mjstef

    mjstef LawnSite Member
    Posts: 145



    House and garage sit in the middle of the acre as well as a 4,000 Sq Ft garden. This cuts out some of the irrigated area. Owner already had some zones in the back yard that where manual. We still have to get the jackhammer back in their to get the main line in to that area. Right now he just drags a hose across the yard to the valve box and hooks it up every few days. There was areas in the front yard where i had to sleeve the 1" pipe inside 1 1/2 to protect the 1". Adding another zone their to keep it under 5 FPS would have added a LOT more trenching, Jack hammering and $$$$$. This is why we pushed the envelope on the system.
     
  10. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,008

    The 'textbook' method to cover an acre-plus with a minimum of trenching would involve high-pressure rotors with radii near to 50 feet, if the well can deliver the needed water. That would save on trenching, but little else, as it could actually mean more zones overall, as maybe only two or three of those rotors could run at a time.
     

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