Selecting a pump for a cistern

[MillWeld]

I need to pump water from a cistern that collects rainwater for garden watering. The cistern is only 5 feet deep and I have installed a foot valve at the end of a 1" pvc pipe by which it draws water which is filtered and sent to a captive air tank. I then use the water via a garden hose just like my domestic water except it has its own hose bib connection. My present pump is inadequate - takes too long to charge the pressure tank and loses its prime too easily so I want to replace it. I am looking at

Surplus Center - 1/2 HP 115/230 VAC WATER ACE SHALLOW WELL JET PUMP

from the Surplus center. It is described as a jet pump which I undertstand uses the Bernoulli principle to pump water. I asked the tech service dept at Surplus Center if this pump would work with my foot valve as described and they said that it would. I don't understand how a jet pump can work in this application. Doesn't a jet pump have 2 lines into the well/tank? one pumping water down the well to a narrow orifice which draws in additional water for the return trip to the storage tank?

I don't want to buy another inadequate pump so I am running this question to the top. I want to keep my plumbing as is and use a pump adequate for it.
Bob

 

[clsathome]

You may want to consider the Simer "pressuremate" 3/4hp pressure booster pump in the Northern Tool catalog. I needed a solution to get irrigation water up the hill behind my home. I did not have enough house pressure to get water up the hill. The unit is ready to install out of the box. I installed it using simple pvc fittings with hose and irrigation line adapters. After installing this pump, I now have no problem getting drip irrigation to 40 6-foot spruce trees 500' up the hill!

 

[Kays Supply]

There are deep well jets and shallow well jets. The shallow well only uses the one suction. The jet is built into the pump. It takes several gallons through the jet to get one gallon out the discharge. If volume is need, a straight centrifugal might be a better choice.

 

[MillWeld]

I installed the pump I referenced above but never got it primed so it has never pumped much water. In trying to get it ready for this gardening season I have dug up the suction line in hopes of finding a PVC connection I overlooked solvent-welding but I found none. I have primed (I think) the line by slowly pouring water in the top of the pump to fill the suction line all the way down to the foot valve. The 1" PVC line slants down all the way to the cistern so there should be no air trapped in the line. Plug it in and pressure rises only to about 10 PSI and the pump runs continously and sounds like the impeller is mixing air and water. Pump housing gets warm. Water w/ air in it comes slowly out of the spigot. I have repeatedly "re-primed" it but get no results. Does know a trick to priming that I am missing? If it will help I will post pix of the setup.

Pressure switch is set at 30 on and 50 off. Air tank is at 28 PSI.

 

[tommu56]

Is it a self priming pump?

what kind of flow do you want?

Do you have a foot valve in tank?

A submersible well pump in the tank with a cross on the discharge with 2 18" of 1" pipe to stop torque and the center of pipe as outlet.

Self Priming Electrics - Self-Priming Utility Pumps

Maltz Sales | AMT Self-Priming Pump

 

[Egon]

What is the height difference between pump and tank water level?

How long is the suction line?

Does the foot valve hold?

 

[MillWeld]

What is the height difference between pump and tank water level?
Only 5 feet

How long is the suction line?
10 feet

Does the foot valve hold?
Yes. I have removed the footvalve via a union (which is above the water) for testing and it holds water and I have the same priming problems with or without the union. So the union does not leak.

Thanks,
Bob

 

[mjw357]

Sounds like you have a leak somewhere in the suction line.

 

[Egon]

Bob, try a larger suction hose, say 2?? inches. The pump information may have suction line sizing. It may have to be the same size as the suction side fitting.

Just run a line above ground as a check to see if that fixes the problem.

 

[MillWeld]

The leak defies location. How would soap help locate it? Air would be drawn in leaving no bubbles. I can get 10 PSI water pressure in the line after running pump. When I shut the pump off I see no water drops but 10 PSI is not much pressure. I talked to Water Ace company and they said a 1" suction line would be fine for such a short run. Here are some pix. There are a lot of connections because I have been making adjustments/changes.

(One of the lines in the trench is a drain for a water softener and has nothing to do with the pump. It is also shown in the crawl space pic.) There is a single 1" line, with part gray elec. pipe, to the footvalve. I know it is not supposed to be used for potable water but this cistern water stinks and will never be drunk.)

 

[radioman]

Is the pipes outside still uncovered? Have you tried to clean foot valve yet?
If I were you, I would google pressure testing the pipes. You may need to replace strainer with a cap and install shutoff before pump and do a pressure test to see if pipe is ok. If it is, then check and recheck connections from shutoff to pump to tank for leaks.
This method is only way to figure it out yourself without guessing if it a prime issue or air leaks.

OTHO, If you have a bad foot valve or cistern doesn't recharge fast enough it would do what you describe.

 

[tnmike]

I used this pump on my cistern that is fifteen feet deep. I had to put a check valve on the intake and outlet at the pump. Throw away the plastic check valve that comes with it and buy quality brass ones. After initial priming the thing has run perfect ever since. The built in pressure tank is a plus. I do not have a foot valve ' just a screen on the bottom of the feed pipe.

1 Horsepower Shallow Well Pump with Stainless Steel Housing

 

[mjw357]

You can test your suction line for leaks by disconnecting the union and connecting your garden hose, should give you 40-60psi. Any leaks that would allow air in should show up pretty fast.

 

[MillWeld]

I like the garden hose idea. Another one that I just thought of is to coat the junction of every fitting and pipe with a heavy oil. If there is a leak the oil should be sucked in and plug it long enough to start normal pumping. Is that a sane idea?

Bob

 

[MillWeld]

I did the oil trick and got no results. Then I pressurized the entire system via a garden hose connected to the prime port. This is the short galvanized section in the pic. It pumped up to 38 PSI and is still holding there after 13 hours. I don't think I have a leak. Defective pump? Call a well guy?:mur:
Bob

 

[Kays Supply]

Is it a jet pump? It could have something lodged in the jet. Check the check / foot valve. They have been known to stick shut.

 

[MillWeld]

The foot valve is not stuck. I have removed the dip pipe with the foot valve on it several times. When I lift it up it holds water, when I turn it upside down water rushes out.

It is a jet pump. To check the jet means removing the motor and dissassembly of the pump, right?
Bob

 

[beeforty]

I used to have a jet pump on my well, and every time I had to disconnect the lines to work on it, when done to get it to prime I had to pour water down the pressure gauge hole with the pump running. As soon as it started spitting at me you had to screw the gauge in so as to not loose the prime. Finally put in a "T" which was quicker to close and let the pressure build up to cut off point. I went to a submersible when I replaced the pump, so much easier.:thumbsup: Jet pumps PUMP water down to the jet which then draws water UP and out.

 

[Kays Supply]

It depends on the pump for getting at the jet. Some are made into the side of the head others are in an adapter screwed to the pump head where the suction connects. You won't need to pull the motor for sure. I have an old one in the shop that actually has a pipe plug made into it so you can remove the plug and run a wire into the jet to clean it.

 

[MillWeld]

I haven't given up on this BUT I have found a smoking A-bomb. A friend suggested the same as Kays Supply, i.e., a clogged jet or nozzle. I took the pump apart and found it wasn't clogged - it was BROKEN. The cone part was broken away from the threads - probably due to the factory torqueing it too tight and not noticing. See pic. Called WaterAce and they will send me a kit containing the new nozzle under warranty. I was impressed with them. The pump is obsolete but they honored the warranty anyway.
Bob