Jet pump question.

[etpm]

This forum seems like the best out of all the forums to post this question because lots, if not most, rural homesteads are on a well. I have two wells, one a deep well that I had drilled and another shallow well that came with the land when we bought it. I have decided to use the shallow well for watering. So I need a pump. I have been looking at portable jet pumps. All the ads for them mention nothing about stopping the flow. They show folks watering with hose and some sort of nozzle. Anyway, can these types of pump be used without turning the pump off when watering is done? I don't mean letting the pump run for hours this way but maybe for 15 or 20 minutes. Is this safe?
Thanks,
Eric

 

[ROUSTABOUT]

This forum seems like the best out of all the forums to post this question because lots, if not most, rural homesteads are on a well. I have two wells, one a deep well that I had drilled and another shallow well that came with the land when we bought it. I have decided to use the shallow well for watering. So I need a pump. I have been looking at portable jet pumps. All the ads for them mention nothing about stopping the flow. They show folks watering with hose and some sort of nozzle. Anyway, can these types of pump be used without turning the pump off when watering is done? I don't mean letting the pump run for hours this way but maybe for 15 or 20 minutes. Is this safe?
Thanks,
Eric

Just add a pressure switch. Maybe a tank to make it all work right.

 

[jaxs]

I don't know what this world has come to. Nothing comes with installation instructions any more. I'm building my own house and can't believe plumbing,hvac,concrete,lumber nor electrical components include installation instructions. Sad to say no one has been able to tell me how in terms I understand.

 

[ponytug]

I think that there are many advantages to a second well for irrigation uses.

However, I wouldn't buy a jet pump for even a shallow well. I think that they may have had a certain utility a long time ago when pipes and labor were cheap, and motors and pumps were unreliable. These days, I would get a submersible pump, and either plumb it into an always on wide open irrigation system, or add a pressure switch and a pressure tank. I have done both, and it is easy, if the well isn't deep. Just my $0.02...

All the best,

Peter

 

[steve tym]

As long as the pump is moving water it will be happy.
If I set up a pump like this for a customer, I normally leave one hose connection without a valve so it is always open.
Or a tank and pressure switch. There are pump/tank packages available out there.

 

[Carl_NH]

If you know the well has a good flow rate and the static water level when pumping is 15-20' a single stage jet pump will work - HD has one for $170. Otherwise you need a more expensive 2 stage pump and two pipes will be able to pump from about 80', might as well get the submersible.

However, I agree with others - get a 1/2HP submersible, tank and switch is the easiest and don't need to deal with priming etc. and pumps dont like to run dry, so get a low pressure cutout switch to prevent running dry.

 

[sandman2234]

I think that there are many advantages to a second well for irrigation uses.

However, I wouldn't buy a jet pump for even a shallow well. I think that they may have had a certain utility a long time ago when pipes and labor were cheap, and motors and pumps were unreliable. These days, I would get a submersible pump, and either plumb it into an always on wide open irrigation system, or add a pressure switch and a pressure tank. I have done both, and it is easy, if the well isn't deep. Just my $0.02...

All the best,

Peter

Having lived in a home with a 110 well and a water table at 90 feet, with 5 kids, 2 parents and 200 head of brood sows, it would have been nice to have a second well to divide up some of that water use! A well has its max capacity in flow, and we reached ours pretty often, which is why I learned as much about pumps and wells as I did!
David from jax

 

[steve tym]

A submersible pump, tank and switch will make your life the easiest.

 

[scootr]

We have 2 wells. Both have submersible pumps at the bottom. They pump into a 5k gal storage tank which has a float valve cut-off switch to tell the wells when to stop pumping.
The jet pump is between the storage tank and the bladder tanks (2). The jet pump has a pressure switch which turns the pump on/off based upon the pressure tank(s) pressure.
The storage tank is uphill from the house and barn. In the event that power and pressure fails we still have a gravity feed.

 

[etpm]

Hi folks,
I understand about submersible pumps, pressure tanks, etc. I am looking to avoid all that. I want to use a portable jet pump and would like to know if I can completely block the flow without damaging the pump. I am not gonna spend the money on pressure tanks and so on. If I want a permanent system I will need to dig ditches for power and put in another well house. I really don't need to do this and don't want to spend the money. I just wanna run an extension cord to the portable pump. Can anyone answer my original question?
Thanks,
Eric

 

[ponytug]

Sure, run the extension cord over, drop the intake hose(s) in the well, and you are good to go. You can block off a centrifugal pump, but don't do it for very long as they can and will overheat. We did something similar for a decade or so to water the the garden, dropping the intake in, connecting the garden hose to the pump, and then plugging in the pump.

I didn't realize that you had the pump. If you don't, you only need the jet pump if the water level is more than 20' or so down, at which point, I would buy the submersible, rather than buying a jet pump... I would make sure that the extension cord connections are protected from water...

All the best,

Peter

 

[3Ts]

The answer to your question as to whether a jet pump outlet can be plugged is "yes, but with a condition". The water in the pump housing is not going anywhere and you're putting energy into it so it will heat up. As long as you don't overheat the pump you'll be fine. I think 20 to 30 minutes is quite a long time but it depends on the ambient temperature and the rating of the pump. A jet pump is a centrifugal pump with a venturi. A centrifugal pump has a disk that rotates to pump the water, if water is not moving, there is no damage to the pump. The venturi has no moving parts.

I used a 3hp centrifugal (not a jet since it did not have the venturi) pump to draw out of a pond for my irrigation system. It ran and I got whatever psi & gpm it would put out for the sprinklers. I did plan the sprinkler layout based on the expected pump flow & psi so there would not be much deadheading.

Here's a link that you may find useful. Jet Pump

 

[Egon]

Put a pressure relief valve between the pump and shut off valve.

easiest is a pressure shutoff. No need for a tank.

 

[CobyRupert]

I think you’re asking if a pump can dead-head without damage. I think there are a couple issues.
Pressure will rise, can the closed off system tolerate this pressure? Maybe experiment and put a pressure gauge to see what that dead head pressure is.
The other issue, as people have mentioned, is will heat rise at the pump? If it’s fan cooled, maybe not. It may be that the pump runs at less power/amps when it is deadheading and NOT working hard to lift pounds of water. One should also note that frequent starting and stopping of a motor (with inrush) may heat a motor more than running a motor. We tend to size motor cables, starters and breakers based on the full load amps of a CONTINUOUS DUTY motor that runs, yet a motor manufacturers have allowable starting intervals and the Electric Codes are different for motors with intermittent duty.
I’m pretty sure there are products that reduce the flow so that the motor runs more continuously. Perhaps a salesmen will chime in and provide more details.

 

[Valveman]

No, you should not completely block flow from a jet pump or any pump. With a jet pump the water will start getting hot in just a couple minutes. Any longer with no flow and damage will occur. You also cannot use a pressure relief valve with a jet pump as a jet pump only builds 50-60 PSI and works at that pressure. A 70-75 PSI relief valve would do no good and the pump will still get hot. The motor is fan cooled and won't get hurt, but the pump is cooled by the flow it is moving, and needs at least 2/10's of a GPM flow to stay cool.

If you have 4" or larger casing, I agree a submersible would be better, and it will work with a pressure relief valve as they build much more pressure than a jet pump.

 

[steve tym]

If the pump is moving water, it's happy. If the pump is running and not moving any water, it will self destruct.

 

[etpm]

No, you should not completely block flow from a jet pump or any pump. With a jet pump the water will start getting hot in just a couple minutes. Any longer with no flow and damage will occur. You also cannot use a pressure relief valve with a jet pump as a jet pump only builds 50-60 PSI and works at that pressure. A 70-75 PSI relief valve would do no good and the pump will still get hot. The motor is fan cooled and won't get hurt, but the pump is cooled by the flow it is moving, and needs at least 2/10's of a GPM flow to stay cool.

If you have 4" or larger casing, I agree a submersible would be better, and it will work with a pressure relief valve as they build much more pressure than a jet pump.

The well is 21 feet deep and 3 feet in diameter. I was thinking that if the flow cannot be blocked for any significant period of time then a relief valve would work. But you say I cannot use one because the jet pump only builds 50-60 PSI. Why cannot I use an adjustable relief valve that opens at, say, 40 PSI. Then watering with a hose, which is what we will be doing, will keep the valve from opening, but when watering stops the valve will open and dump the water back into the well. I don't know where to buy one of these relief valves if they exist but I'm thinking they must. If I do buy a submersible can I use a pressure relief valve that just dumps the water back into the well? I really want to avoid the use of a tank and pressure switch because if I do then the whole business starts to get pretty expensive. I would need a tank, switch, CSV, and pump. Just for running one hose.
Thanks,
Eric

 

[etpm]

Looking online I found a submersible pump made by Vevor that fits the bill for my use. It will go to 79 PSI so I could use a 70 PSI relief valve that just dumps the water back into the well. Submersible pumps are way better than jet pumps efficiency wise. I also like the idea of having no pump on the surface and so not having to worry about priming a pump. I could use a small tank and pressure switch I suppose but I would rather just have the pump run continuously when I'm watering, turn it off with a switch and then unplug it because the pump will be powered by an extension cord for the foreseeable future. BTW, the word "foreseeable" just looks wrong. Like there is an extra e.
Eric

 

[ponytug]

I would just add an inline pressure switch. They are inexpensive, and will simply turn the pump off when the hose kinks or someone shuts a hose nozzle.

All the best, Peter

 

[etpm]

I would just add an inline pressure switch. They are inexpensive, and will simply turn the pump off when the hose kinks or someone shuts a hose nozzle.

All the best, Peter

I'm hoping to find a pressure relief valve that dumps the water back into the well whenever the hose is shut off. The well is for sure not potable because it is surface water. Because of this when done using this well for watering the pump will be unplugged. We could, I suppose, try to seal off the top of the well so that not even a bug could make it past the seal, but that won't do anything about the surface water that fills the well. And I have no idea what kind of bacteria there could be in the surface water. We have lots of deer and deer poop can carry the type of e-coli that makes humans very sick. And deer for sure poop near this well.
Even though the top two feet of the well is a square concrete construction the remainder is just a 3 to 4 foot diameter hole in the ground. As the ground water level changes so does the well. During the time of the year when the ground water is highest the water in the well is about two feet from the ground surface. When the ground water is at its lowest level the well water surface is about 18 feet below the ground surface. It's interesting to watch the level change because it lags the rains. So the water level continues to drop after the rains have stopped and then when the rain starts again it rises a few days after a big rain.
Eric