Need engineering help! water pump

Robbie · Post by **Robbie** » Mon Jun 20, 2016 8:14 am

I would like to build some kind of pump to drive water from our creek to our pond. We do have a gas pump, but I'd like to build a gravity driven system that runs on it's own. My problem is, the creek is at the bottom of a valley and I estimate I'd need about 30 feet of lift and around 250 feet of distance to travel. I have 1 1/2" hose.
Any thoughts? What would be the best kind of pump to build? What calculations do I need to make? I don't want to build the thing first only to find out it won't work!

Post by **Home Grown Poultry** » Mon Jun 20, 2016 10:17 am

you would need a windmill. im building a small one to filter n circulate the pond but I have not started.

Post by **WLLady** » Mon Jun 20, 2016 10:21 am

There are water ram pumps....but i don't think they would lift that height and move enough water for you-they also waste a ton of water onto the ground during the "ramming" process. so you "use" lots of water, to move a little.
I think Al's idea of something to drive it-windmill-is a great one. or maybe go solar battery driven and chain it to a huge tree/rock/something so it doesn't get ripped off.

Post by **Home Grown Poultry** » Mon Jun 20, 2016 10:43 am

I have this little ornamental windmill that I recovered fom the old place out of the old bush dump site n it was at the bottom of the hill. but I just couldnt understand why someone would throw it out or why people used to think dumping any n everything into the bush makes stuff disappear? if I take the wire off of the blades it has tonnes of power and wants to fly away LOL.

so iv thought about putting an alternator on it to charge a battery and run a 12v bilge or water pump to push the water into a biological filter then over a waterfall and back into the pond. but I also have a mechanical water pump from a washing machine its belt driven, not sure it it would work yet as I think it needs to be lower than the water level, shall see. BUT I think i have a better idea and thats to use the base from a sump pump, basically just remove the motor and hook up the axel to the windmill. but im still thinking n havent engineered anything yet.

BerryHill has actual old fashioned windmill water pumps, although quite expensive I think they are build right and would pay for themselves eventually.

http://www.berryhill.ca/mobile/Category.aspx?id=1846

Robbie · Post by **Robbie** » Mon Jun 20, 2016 11:32 am

Thanks everyone- So if I build a windmill at the top of the valley, will it lift the water 30' (I'm guessing, it could be more) from the creek at the bottom? The creek is in a wooded valley, so no wind/sun down there. How would I calculate how big a windmill I'd need?

muffin57 · Post by **muffin57** » Sat Jun 25, 2016 2:10 pm

My husband suggests a piston pump at the water source to eliminate the lift problem, as water is easier to push than to lift. The piston pump requires low horsepower and may possibly be converted to a 12 volt motor or use an invertor to run the 110 quarter horse motor that they come with. Hope this helps.

Post by **poultry_admin** » Sat Jun 25, 2016 3:23 pm

Pumps need to create a vacuum to pull. That means that you need to have a GREAT seal around the pistons to create a big vacuum. BEST (Expensive) pumps can get 10m lift on the suction side. Any more, and they boil the water instead of lifting it. So, cheaper pumps, and a 3ft lift is doable.

Pushing is much easier. Pistons and jets are suitable for high lift. Piston will need a bigger starting current for the motor to turn over and a higher running current (friction of pistons that jets don't have). Jets will need good footer valves, the have poor suction capability. Mine is 4 ft over the water level and I have a hard time priming that one....

Calculation:
http://www.engineeringtoolbox.com/pumps ... d_505.html

Robbie · Post by **Robbie** » Sat Jun 25, 2016 4:23 pm

I'll do a bit more research, we need a pump that doesn't rely on gas or plug in electricity.
Although if this drought continues, there won't be much creek any more to irrigate from so a moot point.

Farrier1987 · Post by **Farrier1987** » Mon Jun 27, 2016 9:13 pm

Pressurewise, water develops a pressure of .433 psi per foot. So if you need to raise the water 30 ft, you will need about 15 PSI just to overcome gravity. To push from there to wherever, friction is the thing to overcome. I knew a guy that had a windmill and he pumped the water from down below to the top of the windmill, then gravity made it flow back down, and he piped it to where he needed it. His windmill was 40 ft high. So in your case, you would need 70 ft of lift, (30 to ground level and another 40 to the top of the windmill) at .433 PSI/ft, would be about 35psi. So whatever mechanical device/pump you use would need to put out 35 psi to work for you, and wherever you are running it to needs to be lower than the top of the windmill for gravity to take it there. Friction is not really much, but the larger the pipe, the less friction.

Hope this helps.

Robbie · Post by **Robbie** » Tue Jun 28, 2016 7:20 am

Yes it does, thanks Farrier!