What is a Submersible Pump?

Submersible pumps are designed to run submerged under water and are used in a wide range of applications.

This makes it possible for the pumps to run directly at the water source and achieve the highest efficiency possible.

The submersible pumps versatility makes them ideal for many different applications from pumping drinking water from deep wells to pumping flood water and sewage.

Due to pumping right at the source, water can be pumped reliably and effectively up to the surface.

Submersible pumps use less energy than surface pumps and deliver a reliable performance in challenging applications, therefore they are a popular choice for many industries.

What is a Submersible Pump?

A submersible pump is a device wherein the pump and motor are submerged within the fluid to be pumped.

It has the motor being hermetically sealed and attached to the pump body.

A submersible pump pushes fluid to the surface as opposed to suctioning or pulling the fluid up to the pump.

Submersible pumps are commonly used in applications such as residential and commercial building water supply and sewage systems.

Submersible pumps are efficient due to not needing priming requirements, therefore they are often preferred over other types of pumps.

The fluid being pumped lubricates and cools the submersible pump motor.

This helps provide longer life than other pumps, so they require less maintenance.

Submersible pumps are less noisy than most other pumps and run smoother, as fluid being pumped muffles the noise.

Submersible pumps are less liable to problems with cavitation, since the submersible pump motor is cooled by the surrounding fluid.

How Does a Submersible Pump Work?

Inside a submersible pump is an electric motor drives an impeller, which is a rotating blade that pushes the water.

When the pump is switched on, water from the source enters the pump through an intake (often through a mesh or foot valve at the bottom).

The impeller spins at high speed, flinging it outward.

Immediately around the impeller is a diffuser or volute chamber that slows the water down and converts kinetic energy into pressure.

The pump builds up pressure and forces the water through the outlet and up the pipe towards the surface.

Many submersible pumps contain multiple impellers stacked in series (a multi-stage design) to increase the pressure for lifting water from great depths.

Operation

The submersible pump sits at the bottom of the well or tank and ‘pushes’ the fluid upwards through the discharge pipe.

This is different from an above-ground pump that would have to pull water up.

By pushing from below, a submersible can raise water from much greater depths.

Because the entire pump is underwater, the motor is continuously cooled by the surrounding fluid and is less likely to overheat.

What is a Submersible Pump Used For?

Submersible pumps are incredibly versatile and are used for a wide range of tasks.

Here are some of the most common uses:

Groundwater Wells

Submersible pumps are commonly used to extract groundwater for residential, agricultural, or industrial supply.

Because they can operate at significant depths, they provide a steady supply of water from underground aquifers.

Sewage and Wastewater

In sewage treatment systems and pumping stations, submersible pumps move wastewater and sludge through the system.

Their sealed design allows reliable operation in contaminated fluids.

This keeps sewage contained as it is pumped to sewage treatment plants.

Oil and Gas Extraction

The oil industry uses powerful submersible pumps (often called ESPs – Electric Submersible Pumps) to lift crude oil or water out of deep oil wells.

These pumps can handle high pressures and temperatures found deep underground, enabling efficient oil production.

Agricultural Irrigation

Farms and irrigation systems use submersible pumps to draw water from wells, rivers, or ponds and deliver it directly to fields.

Submersible irrigation pumps are prized for their ability to efficiently provide water for crops, improving water usage and crop yields.

Flood Control and Dewatering

Portable submersible pumps are indispensable for removing unwanted water during floods or at construction sites.

They are used to rapidly pump out flooded basements, trenches, or pits.

This helps to keep work areas dry and minimise water damage.

Industries that Use Submersible Pumps

Submersible pumps are used across a wide range of industries.

Their ability to operate underwater and handle different fluids makes them suitable for many sectors:

Water Supply and Distribution

Water utilities and industries use submersible pumps to source and distribute water.

These pumps draw water from underground wells or reservoirs and send it into the water supply system.

Submersible well pumps ensure that clean water can be lifted from deep aquifers to water treatment facilities or storage tanks for public use.

Wastewater and Sewage

Wastewater treatment plants and sewer systems rely on submersible pumps to move sewage and effluent.

A sewage submersible pump can sit in a collection sump or pit and pump raw sewage, wastewater, or industrial effluent onward to the next stage of treatment.

Due to these pumps being submerged, they keep harmful waste contained.

They can even grind up solids to prevent clogs in the system.

Mining Operations

Mining operations often need to remove water that seeps into mines.

Submersible dewatering pumps are used to clear water from mine shafts or open pits.

This ensures the mining area stays dry and safe.

They help prevent flooding in mines and allow work to continue by continuously pumping groundwater away.

Oil and Gas Industry

The oil and gas sector employs submersible pumps for pumping fluids from wells.

In petroleum production, electric submersible pumps are lowered into oil wells to push oil to the surface.

These downhole pumps are built to withstand high pressures and temperatures.

This enables efficient extraction of oil and brine from deep underground.

Agriculture and Irrigation

The agriculture industry uses submersible pumps for reliable water supply to farms.

Farmers install submersible pumps in boreholes or irrigation wells to pump water for crops and livestock.

These pumps run immersed in the water source and can deliver a steady flow for irrigation systems, even in remote rural locations.

Construction and Dewatering

Construction sites use heavy-duty submersible pumps to manage water intrusion.

For example, if a building excavation or trench fills with groundwater or rain, a submersible dewatering pump can be deployed to pump the water out and keep the site dry.

This allows construction work to proceed and prevents water-related damage or delays.

Types of Submersible Pumps

Different jobs call for different types of submersible pumps. Here are the most common types available:

Well (Borehole) Pumps

These submersible pumps are long, narrow units designed to fit inside drilled wells (boreholes).

These are used to push water up from deep underground.

A borehole pump usually has multiple stages (stacked impellers) to build enough pressure to lift water to the surface for domestic water supply or irrigation.

Well pumps are installed deep in wells and can reliably provide water for homes, farms, or even water systems.

Sump Pumps

A sump pump is a small submersible pump typically installed in a basement or crawl space to prevent flooding.

It sits in a sump pit, and when water accumulates, the pump automatically switches on to pump the water out to a drain or outside area.

Sump pumps are commonly used in homes to stop groundwater or rainwater from flooding the basement.

They are designed for intermittent use and usually come with a float switch that turns the pump on when water rises.

Sewage Pumps

Submersible sewage pumps are built to handle raw sewage and wastewater without clogging.

They are often used in septic systems, sewage lift stations, or wastewater treatment facilities.

A sewage pump can tolerate solids and may include a grinder or cutting mechanism to chop up materials before pumping them onward.

These pumps allow sewage and grey water to be moved from lower to higher elevations.

Slurry and Sludge Pumps

Slurry pumps and sludge pumps are heavy-duty submersibles designed for liquids that contain a high concentration of solids.

They are commonly used in mining, dredging, or wastewater processing where sand, mud, or thick sludge needs to be pumped.

These pumps are made of tough, wear-resistant materials and often have agitators or open impellers to keep solids suspended.

This lets them handle abrasive mixtures and dense slurries without jamming.

This usually means they are larger and more powerful than standard water pumps.

Dewatering Pumps

‘Dewatering’ refers to removing unwanted water, and submersible dewatering pumps are used anywhere that water needs to be pumped out.

They can quickly pump out groundwater, rainwater, or floodwater to keep a work area dry.

Dewatering pumps tend to be portable and capable of high flow rates, but they are generally meant for water with minimal debris.

For example, a construction crew might lower a submersible dewatering pump into an excavation pit after heavy rain to clear out the water.

Submersible Pump Limitations

While submersible pumps are powerful and versatile, they do have some drawbacks:

Cost

One drawback is the initial cost as they are often more expensive to purchase and install than equivalent above-ground pumps.

Installing or retrieving a submersible pump can be complex, especially for deep wells, because it requires special equipment to lift the pump out for servicing.

Maintenance

Routine maintenance is more difficult since the unit is not easily accessible underwater.

Pumps in deep wells may be left running until failure because pulling them up is laborious.

Any repair or inspection means removing the pump from the liquid, which can be time-consuming.

Reliability

Another concern is reliability in harsh conditions.

The pump’s electric motor must remain sealed from water.

If the seal fails or corrodes, water can leak into the motor and cause a short-circuit.

Over time, minerals or debris in the water can cause wear or clogging.

While many designs can handle dirty liquids, a submersible pump can still get clogged or damaged by large solids.

This is especially true if it’s not the right type for that job.

Water Levels

Additionally, these pumps rely on being submerged for cooling.

This means that if the water level drops too low and the pump runs dry, it may overheat and be damaged.

Using the proper materials (like stainless steel) and protective features can mitigate some issues, but it adds to the cost.

Key Takeaways

You should now have more of an understanding of submersible pumps.

Submersible pumps have proven to be invaluable devices for moving fluids in a wide range of settings.

Their submerged design gives them unique advantages as they can push water up efficiently without priming.

General users and professionals alike depend on these pumps for dependable water supply, flood control, irrigation and more.

While it’s important to be aware of their limitations, a well-chosen submersible pump can deliver reliable performance for many years.

For more information on submersible pumps, or any of your pumping needs, get in contact with us here at KD Pumps.