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sprinkler main line

Discussion in 'Irrigation' started by bayaa, Jan 20, 2002.

  1. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Posts: 1,712

    1" everything and a pressure regulator to match the zone flow.
  2. I'll bet I know the next question.....what is zone flo.......?
  3. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Posts: 1,712

    Now stop that Tony, behave yourself.

    Hey what are we doing about service contracts?
  4. bayaa

    bayaa LawnSite Member
    Posts: 43

    Im going with one inch valves then reducing to 3/4 laterals. I say that the zone flow is what the pressure that is need to operate the heads that one is using for optimal performance
  5. Actually, the flow is the GPM of ALL HEADS on a zone. GPM is gallons per minute. Each head that will be on a zone should be added up and totalled. The total GPM should not exceed the capacity of the pipe used.

    Harold, I am going to send you a copy of the service contract I just put into play. I sent my newsletter out 1 week ago and I have already signed up 5 contracts! I actually plajorized someone elses, should work good though~!
  6. aquaturf

    aquaturf LawnSite Member
    from MA
    Posts: 28

    We do everything with 1" line, and you may even consider 1-1/4" main lines for pressure that high. What kind of volume are you getting at 110 psi? That is quite a bit of pressure for a residential job.
  7. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Posts: 1,712

    What does main size have to do with pressure?
  8. "what kind of volume are you getting at 110psi?"

    What volume do you want!!!!

    Geez........Can you believe this Harold?
  9. Planter

    Planter LawnSite Member
    from Utah
    Posts: 214

    The limiting factor on the flow is going to be the meter size. Over-clock the meter by trying to pull more flow through it than it can handle and the water company will be chasing you down to pay for a replacement.

    Additionally, the service line size will also be another limiting factor.

    It is generally not a good idea to drop down in size to a lateral line smaller than the size of the valve. I have seen the cheaper valves that don't want to turn off when this is done. Using a 1-inch valve and dropping right down to a 3/4 inch lateral is an example. 3/4-inch line, as a rule of thumb, will only handle about 9 GPM, which is about not a lot of flow and will severely limit the number of heads you can safely use. Valves can flow enough water to handle one nominal size larger pipe than the size of the valve, i.e., a 1 ½-inch valve can handle the flow from a 2-inch line.

    Hope this helps.

    Hydraulics is a science and we have all seen systems messed up by poor hydraulic engineering.

    Bayaa, I'd recommend you take a class or at least get a text on design. If you can’t take a class you may want to get one of the design books offered by Rainbird or Hunter for professional installers, study it and ask questions.

  10. Planter, I'm sure there are classes in your area of the country too.

    The quote above is wrong........Are you saying we should size our valves to our laterals? That's what it appears you are saying. LImiting the size of our lateral lines to "1 size above the size of the valve" would not be the answer. As for the valve not shutting off, it is not because it has a 3/4 line hooked to it. Do you think the valve realizes this? Do you know what a "flow control" is? Also, 9gpm is a little conservative for 3/4 pipe.

    I am all for giving advice at this site, however let's make sure the advice is good.

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