How Does A Jet Pump Work: Different Type Of Jet Pump And Facts

This article talks about how does a jet pump work. Pumps are normally used for sucking water from one place and transferring it to other place when the movement of water does not take place on its own.

There are many types of pumps which are used according to the requirements of the application. We cannot simply use any pump wherever we want to use. This article focuses only on the jet pump. We shall study what a jet pump is and how does it work and in what all applications the jet pump is used.

What is a pump?

A mechanical device that transfers the fluid from one place to another by utilising power in the form of electricity.

A pump is needed where the fluid won’t go itself, it will need an external source to take it from one place to another. This usually happens when the fluid moves from a lower potential to higher potential. Just like a ball cannot go up on its own and but it can come down on its own, the fluid also cannot go up on its own. It will need pump to get to the top.

What is a jet pump?

From many types of pumps present in the industry, we will study about the jet pump. The term jet suggests that it has a nozzle or small convergent area that will increase the velocity of the fluid.

The fluid velocity increases as a result of increasing pressure at the convergent area. The jet pump uses a centrifugal pump and injector. A high impulse stream is produced by the jet pump. In further sections we shall study about the different applications of jet pump and the simple working of jet pump.

How does a jet pump work ?

The main working prinicple of a jet pump is the venturi effect. The jet pump starts off as a conventional centrifugal pump.

The air inside the assembly is spilled out as soon as the pump starts, due to this a low pressure is created and hence the fluid is lifted up. The fluid right before entering the pump, passes through a venturi which increases the velocity of the fluid. Due to this a pressure difference is created again. This way the movement of water becomes more aggressive. This is how the jet pump works.

Jet pump working diagram

We have already discussed what a jet pump is and also discussed about its working. Now let us discuss about the working diagram of a jet pump.

In this section we will see the wroking diagram of a jet pump. The diagram below shows neat diagram of a jet pump.

How does a jet pump work
Image: Jet pump in a jet ski

Image credits: Wikipedia

How does a jet pump work for an oil well?

The jet pump is located at the bottom of an oil well. The jet pump is modified for the production of oil and gas production for making their production easier.

The main contents of a jet pump used in oil wells are- a diffuser, throat and nozzle. The main working fluid is pumped through the nozzle. This creates suction for the produced fluids. Now there are two fluids in the system- Suction fluids and produced fluids. These fluids are mixed inside the throat and the resulting mixture then passes through the diffuser.

How does a jet pump work for a jet ski?

Jet skis are used in water sports. They can be referred to as bikes running on water. They can achieve high speeds and this high speed can be achieved using a jet pump.

The jet ski moves forward using the third law of motion. As the throttle is applied, the pump starts moving and starts sucking water from the water body. The jet pump ejects the water with a high force. Due to third law of motion, an equal force is exerted on the jet ski, this opposite force is used to move forward.

How does a jet pump work on a return fuel system?

A return fuel system comes with a hose connected with a carburettor. The sole puprose of a return fuel system is that it sucks down the excess fuel sent in the system.

We all know that the fuel is at high pressure, this high pressure fuel creates a suction or venturi action inside the jet pump. This venturi action causes the excess fuel to be drawn out towards the fuel tank. The fuel is transported between the fuel tanks through the auxilliary pipe systems.

How does a two line jet pump work?

As the name suggests a two line jet pump uses two pipes, a larger pipe for upstream and a smaller pipe for downstream.

Two line jet pumps take the help of venturi that is situated at the bottom of the pipes. Through this venturi water is pumped upward. These can be used in wells, a lake or even a water tank.

How does a convertible jet pump work?

A convertible jet pump is a versatile pump mainly used for applications like pumping water from lakes, wells or sprinkler systems.

The principle used in jet engines is used in convertible jet pumps. In convertible jet pumps also, a nozzle and a venturi is used to pump the water. The convertible jet pumps have internal components made of thermo plastics and some times iron too. Since iron is stronger it is long lasting than the ones made of thermo plastics.

Types of jet pump

The jet pump is classified on the basis of depths that the pump can work in. Different types of jet pumps are designed for different types of depths. Below section tells us about the classification of jet pump in brief.

  1. Shallow water jet pump– As the name suggests, this type of jet pump is used to draw water of shallow depths. That is this jet pump can draw water out of a water column which is 25 feet deep.
  2. Deep water jet pump– The depth upto which a deep water jet pump can work on is between 25 feet to 110 feet. As the name suggests a deep water jet pump is used to draw water out of deep water columns.

Can you use a jet pump without using a pressure tank?

Jet pump works on the principle of high pressure jets that are used displace the water or any other fluid from one place to another. This high pressure is provided by pressure tanks some times. But these pumps do not necessarily need pressure tanks.

This pressure makes the flow of stream faster and displaces the targetted fluid. Although, a jet pump can work without a pressure tank also. This can be done in expense to wearing of the pump. Hence it is desirable to have a pressure tank in a jet pump.

What is a turbine pump?

A centrifugal pump that is installed underwater and is connected to an electric motor via shaft is known as a turbine pump. Its basic function is to pressurise the fluid and send it to the desired location to serve its purpose.

The efficiency of these pumps are very high and they are mainly used for large pumping applications. The pump works with various stages, analogous to a train being pulled by multiple engines because the load of train is so much that a single engine cannot drive. Turbo pumps are usually used inside rockets to pressurise the rocket fuel and oxidizer.