Pump advice

I'm looking for a portable pump to draw water from a 14' dug well and a shallow 1.25" well point (alternately) for use in the garden. The pump should be able to drive 150-300 gph up to 600 ft at 15-20 psi. Because there is no electricity at either source, and because I need something that's relatively hassle-free, I am thinking a small gas pump. But even the smallest gas pumps far exceed the specs I need. For example:

A 1 inch clear water pump with 25 cc engine => 2k gph at 52 psi

A 2 inch trash pump with 160 cc engine => 11k gph at 42 psi

Obviously I can use a pressure regulator. Maybe I am betraying my ignorance about how pumps work, but I am concerned that even throttled all the way back, pumps like these will overpressure themselves, blow out fittings, etc.

Can anyone speak from experience about using pumps like these for very small volumes and low pressures? Or does anyone have other suggestions?

Many thanks,
stickler

Andrew Breem wrote:I'm looking for a portable pump to draw water from a 14' dug well and a shallow 1.25" well point (alternately) for use in the garden. The pump should be able to drive 150-300 gph up to 600 ft at 15-20 psi. Because there is no electricity at either source, and because I need something that's relatively hassle-free, I am thinking a small gas pump. But even the smallest gas pumps far exceed the specs I need. For example:

A 1 inch clear water pump with 25 cc engine => 2k gph at 52 psi

A 2 inch trash pump with 160 cc engine => 11k gph at 42 psi

Obviously I can use a pressure regulator. Maybe I am betraying my ignorance about how pumps work, but I am concerned that even throttled all the way back, pumps like these will overpressure themselves, blow out fittings, etc.

Can anyone speak from experience about using pumps like these for very small volumes and low pressures? Or does anyone have other suggestions?

Many thanks,
stickler

you can add a bypass return on the outlet line of the pump. This is basically a t with a valve to throttle the bypass. Valve fully ooen=all flow diverted to bypass. You have the bypass either dump back to the reservoir or to the inlet side. This is not an efficient way to run but will keep pressure low

I would go for the 25 cc motor and see what pressure you get with 600 feet of hose, I would expect with that amount of hose the pressure drop in the hose may solve the problem on it's own. If you still want to reduce it more use a valve at the outlet of the pump, water will circulate in the pump and as long as you have flow it will be fine. Note that if you use a nozzle on the end of the hose and shut off the flow, then the water in the pump will heat up.

Great idea about the bypass valve. With that in mind, I'm inclined to go for the bigger pump. The two are about the same price, and the bigger one--while less efficient for this--is potentially more useful for other things. Thank you both.