gas powered water pump : LUSENET : Countryside : One Thread

need a gas powered water pump that is self priming, and that can deliver 1500 gal. in a somewhat short time, to a tank that is about 60 feet vert and 300ft in distance from the pump..the suction will be about 20 ft. and a distance of about another 200 ft. the source is a stream that has a pretty big flow. can anyone recomend a reliable pump that can do this job?

-- Richard Armstrong (, November 06, 2001


Richard, try this web site, do a search for what item you are looking for. they have a good variety of water & trash pumps, etc. you can compare price & features. good luck ! Larry in OK

-- Larry in OK (, November 06, 2001.

I use a gas trash pump to lift water about 28 ft. out of a well. I pump the water into a stock tank to water the garden. Works great. You could find one at farm stores in your area but Northern has a very good selection. They ship very quickly too.

-- Tom S. (, November 06, 2001.

Most any farm supply store would have that item. As mentioned by another, Northern tools or harbor Freight would also have them. Any good plumbing store should as well.

-- Gary (, November 06, 2001.

Incase youre looking for a used one you might want to check e-bay to.

-- Dave.??? (, November 06, 2001.

A trash pump would do it easy but mine is not self priming. You could put a check valve on the suck line.

-- Mel Kelly (, November 06, 2001.

You have all the data to make an informed choice.

What you need to look at is the total head capability of the pump and its rated horsepower.

You have an approximate suction head of 20 ft plus the discharge head of 60 ft, a total of 80 ft. To that you need to add the line losses generated by the horizontal runs -- substantial, depending upon the line sizes. It's not an unreasonable thing to double the net positive head -- 80 ft -- to obtain the necessary pump size.

You don't say what the 'somewhat short time' is that you wish the 1500 gal tank to be filled within. So let's assume two hours.

One gallon H2O = 8.3 lb One horsepower = 33,000 lb ft / minute Water pressure in pounds / sq in = approx 0.441/ft of elevation (height)

You wish to have 1500 x 8.3 = 12,450 lb of water raised a nominal lift of 80 ft / 120 minutes = 8300 lb ft / min

Disregarding line loss (500+ ft; WOW!) and asuming the tank to be at atmospheric pressure, the hp needed works out to be about 1/4 hp. This is unrealistic. Even a factor of three increase in pump size (to compensate for line loss and pump/motor inefficiency) would indicate a 1 hp pump -- realistic only if you're using an electric motor. Gasoline would need to be at least a 3 hp.

My suggestion is to get a diaphragm (positive displacement) pump of the 6-8 hp range. You'll be able to run the pump's engine slower and prolong its life and the reserve capacity will be there if ever needed. The suction line foot valve someone suggested is an excellent idea; will minimize the run time needed to get the pump primed. A relief valve on the discharge side set to open at somewhere around 40 psi will prevent damage to the pump/engine if for some reason the discharge gets plugged or kinked. A rotary (centrifugal) trash pump will be very inefficient at low speeds due to the high clearances.

If this ain't helped, we tried... Mac

-- McAn Fitzwilly (, November 06, 2001.

A note to Mac....please explain the difference between the two types of pumps you mentioned. I am considering a centrufugal on at 4 horse...not enough HP?

-- Richard Armstrong (, November 06, 2001.

A note to Mac....please explain the difference between the two types of pumps you mentioned. I am considering a centrufugal on at 4 horse...not enough HP? also... some of the trash pump info says that I should not use them to pump liquid for human consumption... is that true?

-- Richard Armstrong (, November 06, 2001.

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