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Using river POC for first time.

Discussion in 'Irrigation' started by jcom, Feb 19, 2007.

  1. jcom

    jcom LawnSite Senior Member
    Posts: 791

    What do we need to avoid for our first river source install? Should start in a couple of months.

    A fast moving, relatively clean river needs what type of filter?

    Using a 70 gpm pump with a looped 2" mainline with 1" laterals zoned at 50 gpm. PGP's and MP rotators for heads.

    We have only one blade for our 255sx. Can we pull 2" if we use additional pulling power in the form of ATV?

    Thanks for the opinions and ideas in advance.

    John
     
  2. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    50 gpm through a 1" lateral? Your looking at a velocity of 14.43 FPS. Your not supposed to exceed 7-5 FPS.

    Are you nuts?

    A looped 2 inch mainline moving 35 GPM (Because its looped) has a velocity of 3.092 FPS, which is safe, but I'd go up to 2.5" because your going to be losing close to 1 psi per 100' feet.

    Have you ever worked with big pipe/large zones before? Your idea is crazy, is this a joke?

    Second, rent a trencher. Or get a bigger plow (410sx with a trailing bullet still has trouble with 2").

    Finally, what is going to happen to the 20 GPM difference between what your using in your zone and what your pumping out of the river?
     
  3. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    The engineering premise on looped main lines is that generally a looped main can be made one size smaller because the flow will be split between the two directional sides of the loop supplying a valve. His 2" main line could therefore carry 70 GPM within the 5FPS standard. Additionally, looped main lines allow for less pressure loss at a given point due to the water travel profile.

    That being said, I still size looped main lines as if they were a standard dead-head main based on the total number of valves (GPM) to be activated off that main line simultaneously. It allows a buffer in the event that things change in the future and additional zones have to be added.
     
  4. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    Agreed, though I thought I specified this in my original post? Its always weird when you have zone lines larger than your looped main coming out of the valve :)

    Regardless, I don't think jcom should attempt this until he does a little reading.
     
  5. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    That it is. But that's the nature of using looped main lines in certain applications. :)

    From what I'm reading I'd agree. He needs to step back a little and either do the reading or have a qualified designer get involved.
     
  6. jcom

    jcom LawnSite Senior Member
    Posts: 791

    This is my first with bigger pipe. My plan was to use 2" fittings and 3-4 1" laterals per 2" valve.

    I have a couple of months to learn what I need to and am starting with input from you folks. The layout I have in mind will use approx. 500' of 2" pipe in mostly sand and was hoping to avoid additional equipment rental. Hence the extra h.p. on the 255sx..

    We are looking at a lift height of 30'. Or is this "feet of head".

    I hope I am not nuts,:rolleyes: but merely trying to get my feet wet.

    Any recommended reading sites, books, etc. is appreciated.

    John
     
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,423

    You can't lift the water thirty feet, if you're talking about elevation on the suction side of a pump. How much acreage is being covered here? Is there an old thread on this install?
     
  8. jcom

    jcom LawnSite Senior Member
    Posts: 791

    We will push the water 30' up at the highest level. The pump will be within 5 ft. of the water.

    I posted lst year on this project but did not get the contract until after freeze up here. Now am trying to put together a final plan so am looking for ideas as to what I need.

    The total coverage area is about 1 1/2 acres I would guess.

    The homeowner has had the electrical work done already. I will have to hook up the pump start and timer but the pump power is in place already.

    Thanks again for all the help.

    John
     
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,423

    I thought this was a familiar situation ~ basically, you need to clear up any confusion about using the owner's old pump. Like looking him straight in the eye and asking him if using that pump is worth the system costing at least a thousand dollars more. If he's handing you a blank check, then go for it, and have fun. Otherwise, get a useful pump for that system, and work from there. Earlier suggestions would allow much smaller pipe sizes, that you can easily pull.
     
  10. jcom

    jcom LawnSite Senior Member
    Posts: 791

    The homeowner does want to use his pump. Says he has a relative nearby using the same thing and it works well. Probably a good idea to go have a look at that system. Sounded like it also had a looped mainline of some type.

    I bid the job high so I have some fudge room built in as to costs, etc..

    Probably have to fly one of you gurus out for the project.

    John
     

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