Looking for advice on pumps to use etc.

Discussion in 'Irrigation / Sprinkler Forum' started by tim0shel, Jul 9, 2008.

  1. tim0shel

    tim0shel New Member

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    10
    What im doing is pumping out of a river to fill a 275gallon + tank, this is as distance of about 250 ft steady going up hill. I need to know what pump to use for this if im going to be running a 1” poly pipe to the tank. Reason for poly pipe due to me possibly having to move the suction pipe if non submersible and if submersible moving it when we get a hard rain for the river will get up and wash debris down that may cause damage. To control this pump I found a on and off flouter switch that I would install inside of this tank so when the level got about half full or so it will come on to fill it back up. From this tank I will be using another pump to run my irrigation that im installing. I don’t know what pump to go with. The tank has at the bottom a 2 inch ball valve out let. The irrigation will have a total of 9 heads so far that are or will be ran like this. One side of the house I have to runs of ½ poly with one head ea. Then I have a ¾ poly ran with one head. This was so I can control them separately right now running from the spigot. I should be able to run all three with the pump.

    The other side I have planed on 6 heads but running 2 lines of 1” poly with 3 heads on ea. Correct me if there is a better way etc.! So the pump to run this setup im un sure of at this moment. I was looking at a 1 hp shallow well pump with a 4.4 gallon tank on it that has a max psi of 72 and 892GPH flow rate. I would take any other suggestions, im still learning all that I can and have not done much calculations on it cause of being confused about some things and what flow for the rain bird heads etc.

    Got to thinking about trying one pump and no tank straight from river to valves for irrigation. Could this work? Total distance would be about 400ft all but the last 100ft on an incline.

    Thanks in advance for any input,

    Tim
    Last edited: Jul 9, 2008
  2. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Assuming 2 GPM per head, and 9 heads running at the same time, that is 18 GPM. At 18 GPM through 1" poly you will lose about 8 PSI per 100'. So 400' will be 32 PSI or 74' of lose. The sprinklers will probably need 50 PSI to function properly, which is the same as another 115' of lift. Then we have to know the amount of actual vertical lift? Add the vertical lift to the 115' and 74', to get total head for the pump. Pump should be able to deliver 18 GPM at this head.

    It will be almost impossible for a jet pump to draw water this far. You need to use a submersible in the river. Using the 275 gallon tank will only complicate the system, as you will now be double pumping the same water, and have two sets of everything to purchase and maintain. 275 gallons in the tank will only last about 10-15 minutes at 18 GPM flow, so both pumps would be running all the time anyway.

    Now for controls. If you do not use any faucets or valves, and hook the pipe directly to the sprinklers, you can just throw on the breaker when you need water. If you control the pump this way, and someone closes a valve, or closes one of those spray handles on a hose, you will burn up the pump.

    To be able to just turn on a faucet and have the pump come on automatically, you need a pressure tank and a pressure switch. However, with a pressure tank and a pressure switch, every sprinkler zone needs to be exactly 18 GPM or the pump will cycle on and off until it is dead. Adding a Cycle Stop Valve before the pressure tank, allows you to use any amount of water you desire without hurting the pump. And adding a Cycle Stop Valve will allow you to use a very small pressure tank, which more than offsets the cost of the CSV.
  3. tim0shel

    tim0shel New Member

    Messages:
    10
    thanks

    Thanks alot for your information valveman!!
    I have been thinking of only running a submersible pump i have been looking at submersible pumps but not really sure what im looking for in one. If only running this one pump where should i place the pressure tank what would be a good size?
    Also what are some ways of figuring the vertical lift?
    Its no problem to spend more money to go larger on the pipe to the sprinkler valves will it be worth it and if so what size should i go with? Would the 1" be sufficient as my only line to 6 of the heads or two lines of 1" 3 heads ea.? I do plan to use an regular irrigation timer for my system and will have valves but i will have the ability to run all of them at once or how ever. So this cycle stop valve you talked about i will need correct?
    Sorry for all the questions i have learned alot in my research for my project but not enough to were im confident that its correct or to start buying up stuff.
  4. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    The tank can be much smaller when using a CSV, and your sprinklers do not have to exactly match the output of the pump. The pressure switch needs to be with the pressure tank, and is usually close to the power supply. From the pressure switch you would run power wires to the motor. Or if it is a 3 wire motor, you would go from pressure switch to a control box, and then to the motor. The CSV would go on the pipe before the tank and before any tees off the line.

    1" poly will lose about 8 PSI per 100'. So if you have short runs this should be fine.

    You could also use the pump start relay in the sprinkler timer to start and stop the pump. Then you would not need a pressure tank, pressure switch, or the CSV. However, you would never be able to run a garden hose for anything, and the sprinkler zones would have to all be exactly the same, or the pressure will vary greatly.
  5. tim0shel

    tim0shel New Member

    Messages:
    10
    Ok so i will not have to worry with a pressure tank etc. Thats what i want to do is run it from my irrigation timer to a start relay. I dont care about using a garden hose etc. When you say the have the Zones exactly the same is that for running them all at once or would i be fine if i zoned them?
    Thanks,
  6. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    You will have to run the correct amount of sprinklers to keep the pump pressure from being too low or too high. If you run too few sprinklers, the pressure will be too high. If you run too many sprinklers, the pressure will be too low. You have to get the zones just right to do it this way.
    Last edited: Jul 10, 2008
  7. Bob NH

    Bob NH In the Trades

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    3,317
    Location:
    New Hampshire
    If you get a submersible pump for pumping from a river you must get one to match the pressure conditions you need. Most submersible pumps from "big box" store are set up to deliver pressure from moderately deep wells, which you do not have. Consequently, they have too much pressure and you waste a lot of power if you don't blow up the pipes.

    As Valveman said earlier, you don't need the intermediate tank and it will be a nuisance and cost more.

    You can use either a submersible pump in the river, or a shallow well jet pump near the river, or a centrifugal pump, often called an "Irrigator". The Goulds Irri-Gator line is an example. http://www.goulds.com/product.asp?ID=88&MASTERID=3

    Those pumps deliver a lot of flow and are tolerant of variations in the capacity of the sprinkler loop.

    If you need less flow and more pressure you can get a 2-stage centrifugal for that application.

    If you flow needs are even less you can use a shallow well jet pump.

    Neither the jet pump nor the centrifugal will over-pressurize your irrigation system and will work as long as you have some reasonable flow.

    You can operate any of them without a tank and pressure switch but the consequence of accidently closing all of the valves with a submersible is that you will probably cause a failure of the pipes.
  8. tim0shel

    tim0shel New Member

    Messages:
    10
    Thanks guys for all of your helpful information. It realy helps me futher into my design and desision making on what i need to do.
    Like i said i plan to gather more data of my area as to the vertical lift etc. and maybe present that to yall to help get some better ideas with the caculations.
    After more research it looks like i will be adding more sprinklers to the system to cover better than what i had. This will make it a bit more complex but at the same time i can make sure i zone them and add vavles that i can control which lines i have open durning the pump runing. I think the control will only turn on the pump if its going to open a zone valve but in the case of a valve failure is there a inline vavle in the mainline that can be installed that will release the pressure if it builds to a preset PSI? Like a blow off valve on a car with a turbo. Haha i had to relate it to a car.
    Thanks,
  9. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Yes you need a pressure relief valve set at about 75 PSI. It is very common for the sprinkler controller to start the pump, only to find that the wires to the sprinkler valves are not working (eaten by a varment or something), and the pump comes on with no place for the water to go. If the pressure relief doesn't blow off, the pump will be toast.
  10. tim0shel

    tim0shel New Member

    Messages:
    10
    Sweet deal i will be sure to get one when putting everything together. Any is fine? what kind or name is good and reliable?
  11. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    All of those little pressure relief valves are pretty much the same. Reliable?? After awhile of sitting in the completely closed position, sometimes they stick closed. Then when you need them, they won't open. This type system usually works well, except when Murphy is around.
  12. tim0shel

    tim0shel New Member

    Messages:
    10
    That makes since i guess it would be good to try open it every once and awhile.
    Still wondering about submerisable pumps and what i can use.
    Im looking at a guessament lift of 35ft and a total length of 400ft. to run which the last 100 flatens out and maybe goes down ward some. Id say about 20gpm flow should work nicely.
    Any pumps out there to handle this effecently?
  13. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    20 GPM at 35' of lift and 50 PSI, equals a 1HP 20 GPM submersible.
  14. tim0shel

    tim0shel New Member

    Messages:
    10
    Wow thats all there is to it huh. Thats what i was thinking about.
    Thanks for you replys
  15. tim0shel

    tim0shel New Member

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    Where is the best location for a relief valve? Closest to the pump or near your valves before going to irrigation system?

    Thanks,
  16. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Anywhere in the line where it, or the water coming out of it, can be seen. This is now your High Pressure Alarm. If you put it in a place where it can't be seen, then you won't know you have a problem until it is too late.
  17. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    The pump model may not be designated exactly 20 GPM. In the Goulds line the 18GS10 is designated 18 GPM 1 HP but when you look at the table or the pump curve http://www.goulds.com/pdf/7310.pdf you see that it delivers 22 GPM at 50 psi with 40 ft of lift.

    You want a pump that is reasonably matched to your demand. It will be less efficient if you operate it at much less than the designated rating. The curves indicate the recommended range of operation.

    The submersible or centrifugal pumps are the most efficient of the pumps that you might choose. A shallow well jet pump is substantially less efficient.

    If you look at the curves the pressure (head) scale is in feet. One psi = 2.31 ft so you would want at least 50 psi x 2.31 + 35 ft = 115 + 35 = 150 ft; and add a bit for pressure loss in the pipe and distribution system.
  18. tim0shel

    tim0shel New Member

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    Thanks Bob, Is there any units that are smaller in length or something that will fit into a small barrel with the same specs?

    Thanks,
  19. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    I don't understand the question about the barrel. Are you going to be pumping out of a barrel?

    Reasonably priced submersible pump are 3.75" diameter to fit in a 4" pipe. Length depends on the HP of the motor and the number of stages of the pump.

    What are you pumping from; river or barrel in the river or the 275 gallon tank?

    You could set a barrel in the earth next to the river with an inlet near the bottom of the barrel (or a flow sleeve on the pump so it gets good cooling) and almost any reasonable submersible would work in a 55 gallon drum. It is important that the water flow over the motor from the bottom to the inlet of the pump which is in the middle.
  20. tim0shel

    tim0shel New Member

    Messages:
    10
    Im pumping from a river and thinking about not using a barrel or anything like that. I was just going to put the pump in a barrel to protect it from stuff in the river if it gets up etc. I like to have it were i can pull it out if we have alot of rain so it dont get washed away. What ever i put it in will act as a extra protector also of debre leaves etc.
    I need a few selections of pumps to chose from im still having a hard time finding one cause i dont want to over kill but also under do it.

    Thanks,
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