What Is a Submersible Pump and How Does It Work?

How Do Submersible Pumps Work?

Submersible pumps work by pushing water to the surface using centrifugal force generated by a spinning impeller. They are designed to operate while completely submerged in water. Here’s a simplified step-by-step breakdown of how they work:

1. Pump is Submerged
   The entire unit—including the motor—is placed underwater in a well, pit, or tank.
2. Power is Supplied
   Electricity flows through a sealed cable, and in some cases, a float switch activates the pump when water levels rise.
3. Motor Activates
   The sealed motor turns on and starts spinning a shaft connected to an impeller.
4. Impeller Spins
   The impeller generates centrifugal force, pulling water into the pump.
5. Water is Pressurised & Pushed Out
   Water is drawn in, pressurised, and forced out through the discharge pipe, reaching the surface.
6. Cooling (If Required)
   In heavy-duty applications, a cooling system prevents the motor from overheating.
7. Pump Turns Off
   When water levels drop, the float switch (if installed) shuts the pump off automatically.

Applications of Submersible Pumps

Submersible pumps are engineered for a wide range of fluid-handling applications across multiple sectors. In addition to the examples below, they are frequently deployed wherever efficient, reliable liquid transfer is required under submerged conditions.

• Water Supply: Used in homes and businesses to draw water from wells, tanks, lakes, and rivers for drinking, cooking, bathing, and sewage treatment.
• Irrigation: Essential in agriculture, these pumps move large volumes of water from natural sources to fields with minimal evaporation loss.
• Mining: Built to withstand harsh environments, submersible pumps extract minerals and resources from underground while handling heat and abrasive materials.
• Construction: Commonly used to remove water, transfer concrete, and assist with foundation and tunnelling work on job sites.

Types of Submersible Pumps

• Sump Pumps: Used to remove accumulated water from basements, crawl spaces, or low-lying areas prone to flooding. These pumps handle clean or slightly dirty water and are essential for preventing water damage in residential and commercial properties.
• Sewage Pumps: Designed to transport raw sewage and wastewater containing solids. Common in municipal, industrial, or residential sewer systems. Grinder pumps, a subtype, shred solid waste into smaller particles to prevent clogging in smaller-diameter pipes.
• Effluent Pumps: Handle treated wastewater (effluent), often in septic systems, to move water from a treatment tank to a leach field or discharge area. Suitable for small solids but not raw sewage.
• Well Pumps (or Borehole Pumps): Installed deep inside wells to extract groundwater for residential, agricultural, or industrial use. These high-pressure pumps are ideal for lifting water from significant depths.
• Dewatering Pumps: Used on construction sites, mines, or flood zones to remove large volumes of water quickly. Capable of handling muddy or sandy water and built for harsh conditions.
• Utility and Drainage Pumps: Lightweight, portable pumps for general-purpose water transfer, such as emptying tanks, clearing shallow floods, or draining pools. Some submersible variants exist for shallow applications.
• Electric Submersible Pumps (ESPs): High-efficiency, sealed motor units often used in industrial or oilfield applications to lift liquids from deep wells. Designed for continuous underwater operation.

Pros and Cons of Submersible Pumps

Key Components of a Submersible Pump

Maintenance Tips

Maintaining your submersible pump ensures long-term efficiency and prevents costly breakdowns. Routine care helps avoid clogging, motor damage, and reduced performance. Here are a few helpful tips:

• Check for blockages around the intake regularly
• Inspect the power cable for signs of wear or damage
• Keep the pump fully submerged while in use
• Clean impellers and the pump casing periodically
• Replace seals or bearings as recommended by the manufacturer

Thinking About Your Other Requirements

Hose – Blue Layflat

Lightweight and compact. Ideal for drainage and temporary hose connections. Easy to store, but not as durable as heavy-duty hoses.

Hose – Medium Duty Green Suction

Heavier-duty, more rigid, and longer-lasting than layflat hose. Great for permanent installations.

Hose Accessories

Connect and secure your hose system using:

• Jubilee Clips – Clamp hoses onto fittings
• Hose Barbs – Allow secure hose-to-pump connections

Final Thoughts

Submersible pumps are compact, efficient, and adaptable to a wide range of applications. From residential water supply to heavy-duty industrial use, their submerged design offers space-saving, quiet, and powerful performance. With proper selection and maintenance, they deliver long-lasting value across industries.

Additional Reading

What Is a Diaphragm Pump and How Does It Work?
Pump Impellers – An Overview of the Different Types
UK Water Regulations & Guidance