Pumping water from lake 100' below for sprinkler system

[speedbump]

There is some very good advice here and some not so good. I like the cistern at the top of the hill idea. Then you can use a 1/2hp shallow well jet to fill the cistern and you won't need a monster pump to do the sprinklers from 100' down the hill. The two horse Goulds self primer you mentioned will not even come close to what you need. It needs to be capable of 192' of head (not counting your suction lift) to give you 40 psi up the hill. It's max head is just over 100'. So at the top of the hill, you would have a trickle.

I would figure out how many gallons per minute at what pressure your heads need for each zone which should be equal. Then get at sizing a pump. It sounds like your intentions are to do this without any professional help at the site, so the more planning you do, the better it will work. If you did go with the cistern, you could use a 1/2hp 10 gpm sub in the cistern that would blow a way a 3/4hp jet pump.

 

[leonz]

As my friend Piloon has said planning the system is the major issue.

Have you considered an air operated diaphram pump??

Simplicity is the key here and it only requires a small air compressor.
An upright tank air compressor with with an oiler and air filter
would work well and only require you to leave the submerged pump
in a bucket with many rows of small 1/8 inch holes drilled in the sides
to screen the water before it enters the suction screen that can be piped
to rise slightly above the pump base.

You would only need to run an air line along with the plastic pipe needed
for the pump as long as you have an open discharge end into an open tank
like a livestock water tank and using a very a small self priming water pump with a
pressure tanks would reduce any wiring issues to an absolute minimum not requiring
a wiring run to the water source and the resulting line drop and problems with amperage
and circuit breakers tripping.


The Gorman Rupp air powered diaphram pumps are simple to use and maintain and a pulsation damper
is the bladder tank and maintains the flow at a balanced rate with a high efficiency and less work.

Installing a a pair of check valves in the hose is a must for any system you install to prevent head loss
and drain back during the pumping.

Adding a pair of Tee's and a ball valve at each T and check valve aids in seasonal drainage for you and you can drain the sandpiper easily after pulling it and the pail out of the water. opening the Tee's when you want to pump water again aids in eliminating any air in the system and thereby compressing it and causing a pipe rupture after the first T and ball valve.


The collapsable discharge hose will work well for this also as long as there is a foot valve at the sandpipers suction port.
T T

 

[leonz]

Adding more to what I mentioned earlier: I believe you have asked this question before.

A two pipe system only has to be as long as the distance to the pump it self as the pump can be located on the dock with the use of a generator if desired making even more efficient or for that matter placing the pump on a small float with a direct burial cable and water proof connections to the pump motor and switch and the pressure tank. The use of single pipe up hill can be limited to a length of 3/4 inch black pvc pipe to a cistern/stock tank and using a very very electric small centrifugal pump to feed the sprinklers.


You need to install check valves for every one hundred foot of pipe to hold the water in the pipe. this is a must have item.

 

[Cord]

I've done something similar and wasn't very satisfied with the performance. I used a 3" trash pump and then built a manifold which fed to hoses that then went to impact sprinklers. The trash pump didn't have tight enough tolerances to build much for pressure. The sprinklers worked, but not very well. The second problem I had was with debris. It doesn't take much to clog a impact sprinkler and I was always having to clean them out. To lift water 100' will max out the capabilities of many pumps. Beyond that you still need another 40psi to make the irrigation system work. Add 20psi if you want it to work well. This is beyond pushing the limits of an "affordable" pump. You might be better off with a two pump solution. The bottom pump would raise the water and then a second pump would boost the pressure. The alternate solution would be to use a well pump. Certainly can get the pressure, lift and flow you are looking for with a well pump. Get familiar with the pump charts and the meaning "dynamic head". I just bought a Tuhorse pump off ebay, model th4-vc and I think it would be just about right for your application. If you go with a well pump, you will need a sleeve to ensure the motor is being cooled.

 

[PILOON]

Trash (sump) pumps move lots of water but do not create much pressure.

I actually have on hand a older but working submersible well pump that we pulled to upgrade due to deepening the well.
It is 1/2 hp 12 gpm .3 wire with control box. Very dirty but works just fine.
Shame is that shipping would just kill the deal as we really would be happy to get , say, $75 ish for it.
I'll probably list it locally.