How Does a Deep Well Jet Pump Work

Most of us live in residences that use well-pumped water. We enjoy the resource running through our taps and showers, but we don’t really understand what it takes for the water to come into our houses.

It may be the least of our concern but knowing how a deep well jet pump works might be of great help someday.

It was never easy drawing water from over 100 feet below the ground until someone thought it through and came up with the deep well jet pump.

Understanding how the pump works can save you plenty of inconveniences in case the pump fails. Note that this pump is designed to pump water from 22-120 feet below the ground.

Ideally, it uses two mechanical principles to draw water from the well.

  • Centrifugal pump
  • Injector (nozzle and venturi assembly)

How it works;

  1. Before the machine is switched on, the pump system and the pipes are usually filled with water. When turned on, the fins attached to the rotating impellers throw the water in the impeller outwards.
  2. In the process, a vacuum is created, and more water is drawn inside the impeller to fill the vacuum. Some water gets into the pressure tank while the rest of the water keeps circling through the driveline into the injector that is inside the well.
  3. A vacuum is then created inside the injector by the nozzle and the venturi. This vacuum makes it possible for water to be sucked through the foot valve. While water goes through the venturi towards the suction line, a sufficient amount of pressure is created to direct the water to the impeller.

How Does a Deep Well Jet Pump Work

A jet pump comprises two significant parts working together; the surface pump and the downhole jet pump. It uses the hydraulic lift system where the power fluids can either be oil or water. The surface pump powers the fluids increasing their pressure as they drive through the piping and the annular space until they reach the jet pump (downhole jet pump)

The three main components of a jet pump are the nozzle, throat, and diffuser. High pressure pumps the fluids from the surface to activate a downhole pump. It applies the venturi principle. Before going through the nozzle, the power fluid usually has high pressure, but the velocity relatively low.

When the power goes through the nozzle, the pressure decreases, and the velocity increases due to the reduced flow area. The reduced pressure then drives the reservoir fluids into the pump, where they mix with the power fluids in the throat area. That area between the throat and the nozzle must be able to accommodate the produced fluids and gases.

This area is critical because it determines the cavitation characteristics of the pump. When the fluids get to the diffuser, the velocity significantly reduces due to increased cross-sectional area, and the pressure increases, lifting the fluid to the surface.

The throat and nozzle area ratio is a crucial determinant in ensuring the jet pump’s excellent performance. Pumps with the same area ratio have the same performance characteristics and efficiency.

How Deep Can a ½ hp Well Pump Go? 

Your pump’s ability to draw water from the well strictly depends on the depth of your well. Expect your pump to always go on and off if it doesn’t match the well’s depth. It may also continue running without actually drawing any water. The sooner you change the pump, the better because you will only be wearing it out and increasing your electricity costs.

For instance, a ½hp well pump can draw water from as deep as 160ft in the case of a submersible pump. A ½hp two-line jet pump can draw water from as deep as 80ft. We can note that regardless of horsepower, the pump model and its performance mechanisms also matter.

Other factors that you need to consider before purchasing a pump include;

  • The well piping
  • Pump model
  • The flow rate of the well
  • Leakages in the system

What hp Well Pump Do I Need?

Choosing the right well pump is not as difficult as it may sound. There are factors you need to consider now that one of your concerns is the pump’s horsepower. Before making your choice do thorough research and, if possible, consult a professional. They will take you through the proper pump selection process for your well.

First of all, you need to know the depth of your well. You may pick a too weak pump for your well just because you did not consider how deep it goes. Most residential homes use 0.5-2.0 hp well pumps.  A 0.5hp submersible pump can draw water from as deep as 160 ft below the ground, while a 0.5hp two-line jet pump can pump from as deep as 80ft.

Depending on the pump model, a 1hp submersible pump can draw water from as deep as 200 ft at 10gph. However, a varying model can pump at a speed of 22gpm at a depth of 40ft. On that note, there are other factors you need to look into before choosing the right pump.

For instance, how fast do you want your water drawn from the well? Other factors include;

  • The well piping
  • Pump model
  • The flow rate of the well
  • Leakages in the system


What is the difference between a jet pump and a shallow well pump?

The main difference between a jet pump and a shallow well pump is that the latter can pump water between 0-25 feet while the jet pump can pump water from 0-25 ft with a nozzle designed for a shallow well and can also pump from 20-90 feet when the ejector assembly is put in place.

How long does a jet pump last?

The average life span of a jet pump is about 10 years. Those that operate above the ground can ensure you enjoy the service for about 5-20 years.

How deep does a jet pump work?

The jet pump can draw water from as deep as 25 feet below the ground. Meanwhile, the deep well jet pump can draw water from as deep as 120 feet below the ground.

Bottom Line

Gone are the days we used to pull water using a bucket and a rope. Given the importance of this resource, there is a need for effortless access to water.

Times have changed, and it is crucial that the residences we live in have easy access to water, and there is no better source than well-pumped water. Deep-well jet pumps have played a vital role, and knowing how they operate is not the worst idea.