How does a Jet Pump Work? | How to install a Jet Pump?

A jet pump is a mechanical machine that flows fluids by a driving nozzle that transforms the pressure of the fluid into a high-speed jet. This jet from the nozzle continuously draws the fluid from the inlet side of the jet pump. In the mixing tube, the trapped fluid absorbs some part of the energy of the moving fluid. The diffuser of this pump retransforms the fluid velocity into the pressure.

A jet pump works by pulling the the water toward the surface instead of pulling it like submersible pump.  It is a self-priming pump with no moving parts. This pump creates a fast jet of almost any liquid and drives another liquid by driving the pressure recovery in the diffuser.

In jet pumps, two or more inlets use to extract a constant flow of liquid, and pressure is used to produce a suction lift. The mixture of the velocity and the inlet pressure of the gases or fluids causes the medium to flow out of the pit, storage tank, or well through the pump up to the outlet point.

Due to some reasons like friction loss, the efficiency of the jet pump is lower than that of a normal centrifugal pump. However, the jet pumps have high efficiency when processing a gaseous mixed media or under various downhole conditions where the surface properties include turbulence.

This pump has one or more impellers and diffusers with an ejector. It installs over the ground, and it pumps the water out of the ground through an inlet pipe. These pumps are famous in regions with high water tables. So, these are appropriate for various residential purposes such as farms, bungalows, oil rigs, and small single-family homes.

If the use of a submersible pump is not recommended or is prohibited by the local government, then it is recommended to use a jet pump to pump water from the well.

Read also: How does a Submersible Pump work?

Working of Jet Pump

The Jet Pump is an artificial lifting system that consists of two main parts:

  • Surface pumping device
  • Downhole jet pump

The jet water pump uses unbalanced air pressure in its working. Its working is very similar as liquid sucks up by a straw. First of all, the pump fills with water. After coupling, the pump impeller rotates and lets water and air bubbles through. During this process, air expels from the emergency shut-off valve, creating a continuous area of ​​low pressure that naturally forces the groundwater upwards.

jet pump working

When liquid arrives in the jet pump, the area of ​​the flow path reduces by an appropriately sized nozzle, thereby expanding the liquid velocity and creating a venturi effect. The pressure difference created by the Venturi effect draws liquid from the reservoir to the jet pump. Venturi can be separated from each other by a certain distance. The drive fluid and the stored fluid mix, and the pressure rises with decreasing velocity through the flow path of the increasing area. The increase in pressure is sufficient to lift the mixed liquid to the surface.

For a better understanding of jet pump working, watch the below-given video:

How to install a Jet Pump

If you want to install you jet pump, follow the below given steps:

1) Make a Horizontal Base: –

Prepare a horizontal concrete base to mount the Mono Jet block and tighten the motor base with the base screws.

Jet MONOBLOCK

2) Pipe Size: –

Use the given pipe size as indicated on the product label.

3) Filters and Valve Inspection: –

Make sure that the jet unit with the foot valve and the filter at the ends of the suction and return lines attache in the borehole (series TDSJ, TSJ, HCSJ). For the HCSJ series, make sure that the attached filter is placed at the bottom of the borehole suction tube.

4) Priming: –

When the first time you turn on the pump, you need to prime it.

  • Air cock doesn’t provide on the HCS 80/11 and TDSJ series. No more water can be added when the pump is primed. Stop pouring water and put the filler cap back on.
  • If the water level in the pressure valve drops continuously during the filling/priming process, this signifies a leak and should be corrected.

5) Set the pressure control valve to the maximum delivery rate: –

The simplest way to set the control valve for the best delivery rate is the visual technique. With this technique, run the pump and adjust the Round Head Screw (15) to measure the discharge rate.

Repeat and tighten the Round Head Screw (15) until water flow to the delivery pipe is maximized. Now lock the Hex. Nut (2) to stop the Round Head Screw (15) from untying. To open the Round Head Screw (15), the pressure valve cap nut (1) must be detached, tightened, and replaced to avoid tampering.

pressure valve assembly, JET pump assembly

6) Electrical equipment installation: –

  • the single-phase jet Monoblock should be grounded.
  • Make sure that the electrical connections (if any) are correctly and properly insulated.
  • Link the cable correctly to the starter clamp so that the connection does not come loose
  • The low-voltage operation should be taken into account when selecting the wire size.

7) Power wire joining to non-clog sewage pump: –

  • Ensure the motor’s internal wiring and pre-connection to the capacitor cables with the two wires appearing out from the junction box cover.
  • Only the phase and neutral conductors may connect to these two wires.

Types of Jet Pump

The jet pump has three main types that are:

  • Deep well Pump
  • Shallow well Pump
  • Convertible Pump

1) Deep well pump

A deep well jet pump uses to pump water from deep underground wells. A deep well is an excavated structure formed to obtain groundwater. These structures create with the drilling method.

deep well pump

A deep well pump is mainly found in rural areas where water is not easily available. These pumps can lift water by suction lift from about 22ft to about 120ft. Deep well jet pumps use the principles of centrifugal pumps and fuel injectors to provide water that meets our requirements.

Mostly these pumps use to pump water to meet household demands. It is also known as a deep-well water pump.

Advantages and disadvantages of Deep well Pump

          Advantages

         Disadvantages

It requires low maintenance and a relatively low price

If the water level becomes below the lower valve of the inlet line, it must be filled with water.

Adapted to draw water from different suction heads

Only submersible pumps can use for higher suction heads.

A deep well jet pump has a low price

Abrasives in wells such as sand can damage the housing and runner.

Easy maintenance

 

Long service life

 

It can install away from the water source.

 

2) Shallow Well pump

These pumps are suitable for reservoirs or wells with a total pump height of no more than 5.5m. The shallow well jet pump uses for purposes where the medium is close to the surface, e.g., residential wells.

Shallow well pump, shallow pump

 

The three major parts of a shallow jet pump are jet assembly, an impeller, and an electric motor. The cost of drilling a shallow well is usually low due to the small amount of labor and material involved. This pump requires for wells less than 25ft in length. However, shallow pumps are not submersible. As an alternative, these set in the well casing.

Advantages and disadvantages of Shallow Well Pump

 Advantages  Disadvantages

This pump can offset the well.

The efficiency of the sallow jet pump decreases with increasing total lift.
Can adapt to wells with different production rates. These pumps have priming problems.
Simple machine, almost maintenance-free. These have cavitation issues.
A shallow well pump is inexpensive.  

3) Convertible Well Pump

The convertible jet well pump can pump water from a depth of 70 feet. It is called a “convertible” pump because it can use as a shallow well pump for water sources up to 25 ft deep and a deep well pump for water sources up to 70 ft.

Well Pumps

It also uses when the pump is above the water source. The convertible jet pump uses two suction pipes to pump water out of the well. As the name of this pump suggests, you can connect the jet assembly to a suction tube and convert it into a shallow bore jet pump. This will reduce the water depth to less than 25 ft. convertible jet pumps can be used in shallow or deep well applications.

Advantages and disadvantages of Convertible Well Pump

Advantages Disadvantages 
Lower price. Cavitation problems.
Needs minimal maintenance. Slightly damaged by sand.
Highly Efficient. Occasionally there are gas blockages.
These Can pump water from deeper depths.  
Large capacity.  

Advantages and disadvantages of jet pumps

The jet pump has the following advantages and disadvantages:

Advantages of Jet Pumps

  • The jet pump doesn’t have mechanical or moving parts that can cause wear & tear.
  • The capability of high productivity.
  • It has a long service life.
  • It needs a low cost for maintenance.
  • By adjusting the engine oil injection rate, it can be adjusted according to the different productivity.
  • Ability to walk for a long time without intervention.
  • These pumps can obtain and exchange quickly and efficiently when maintenance is needed.
  • Very high tolerance to abrasives in manufactured liquids.
  • The use of CRA materials or inhibitors in the fuel fluid makes it more resistant to corrosive fluids.
  • It can use in wells with large deflection angles without damaging the pipe.
  • The advantages of circulating the downhole pump in and out of the wellbore involve decreased downtime and the ability to remove casing, cables, or tubing without a puller.
  • It can handle high GLR.
  • Appropriate for remote working.
  • It can also be mounted on the entire air transport chuck with compression fittings and pipe plugs.
  • It can also install in nipples and sliding sleeves with a cable.

Disadvantages of Jet Pumps

  • It is low efficient than other artificial lifts
  • Space limitation problems
  • It has high-pressure surface lines 
  • It also consumes high power

FAQ Section

Can a Jet Pump overheat?

  • If a jet pump continuously works in the voltage range above 240 volts or below 170 volts, it can overheat.
  • The pump also fits with T.O.P (thermal overload protector) to avoid motor overload.

What is the difference between a Turbine and a Jet Pump?

turbine vs jet pump

A turbine pump is a centrifugal pump that is essentially installed underwater and connected to an electric motor (install on the water surface) with the help of a shaft.

Turbo pumps have high efficiency and mainly use for large pumping functions. This pump generally has various stages, with each stage fundamentally being a separate pump stacked on top of the lower stage. It acts like a train pulling with more than one engine, and each stage is an engine. There is also a big electric motor attached to its end. A jet pump works similar to a turbopump but returns water to the inlet to help lift the water.

See More:

1) What is a Pump and its different types?

2) How does a Solar Pump work?

3) What is the working of a Septic Pimp?

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