A submersible well pump is a type of pump designed to operate completely submerged in water, typically installed in deep wells to extract groundwater. Due to its high efficiency, stable operation, and compact structure, submersible well pumps are widely used in agricultural irrigation, municipal water supply, industrial water systems, and groundwater extraction.
Unlike surface pumps, submersible pumps push water to the surface rather than pulling it, which significantly improves pumping efficiency and reduces the risk of cavitation.
Main Structure of a Submersible Well Pump
A typical submersible well pump consists of several key components that work together to ensure reliable underwater operation.
1. Pump Body (Pump End)
The pump body is the hydraulic part responsible for water delivery. It usually consists of:
Impellers – rotating components that generate centrifugal force to move water upward
Diffusers – stationary parts that convert velocity into pressure
Pump shaft – connects the impellers and transmits rotational power
The pump body is usually made of stainless steel, cast iron, or bronze depending on the application and water conditions.
2. Submersible Motor
The motor is installed directly below the pump and provides the power required to drive the impellers.
Key characteristics include:
Fully sealed waterproof structure
Oil-filled or water-filled design for cooling and lubrication
Long-term underwater operation capability
The motor is connected to the pump shaft and drives the impellers through rotation.
3. Pump Shaft
The shaft connects the motor and impellers and transfers rotational energy from the motor to the hydraulic components.
It is typically made from high-strength stainless steel to ensure corrosion resistance and durability.
4. Mechanical Seal
Mechanical seals prevent water from entering the motor chamber.
High-quality submersible pumps often use double mechanical seals, which greatly improve sealing performance and extend service life.
5. Intake Screen
The intake screen is located at the bottom of the pump and serves to:
Prevent large particles from entering the pump
Protect impellers from damage
Improve operational reliability
6. Check Valve
A check valve is typically installed in the discharge pipe to prevent water from flowing back into the well when the pump stops.
This helps protect the pump and maintain system pressure.
| NO. | Name | Material |
| 1 | Base | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 2 | Reulation Membrane | Rubber |
| 3 | Thrust Bearing | M201B* |
| 4 | Thrust Plate | 3Cr13 |
| 5 | Lower Guide Bearing Bracket | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 6 | Motor Casing | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 7 | Rotor Shaft | 45#Steel,3Cr13 |
| 8 | Upper Guide Bearing Bracket | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 9 | Framenwork Oil Seal | Rubber* |
| 10 | Rejection of Sanding | Engineering Plastics |
| 11 | Connection Segment | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 12 | Key | Steel |
| 13 | Coupling | 35#Steel,SS304/316 |
| 14 | Inlet Section | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 15 | Impeller Shaft | 35# hard chrome plaed,3Cr13 |
| 16 | Impeller | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 17 | Conical Socket | 45#Steel,3Cr13,SS304/316 |
| 18 | Pump Bowl | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 19 | Shaft Bearing | Rubber*,Bronze* |
| 20 | Sealing Ring | Cast iron,SS304/316L* |
| 21 | Diversion Shell | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 22 | Bumper | Rubber* |
| 23 | Check Valve | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
| 24 | Non-return Valve Body | Cast iron,304/316/316L/2205/2507/904L SS,Bronze |
Remarks:
1. The parts with* are quick-wear parts
2. Pump material can be changed based on your request
3. High head submersible water pump.
Working Principle of a Submersible Well Pump
The working principle of a submersible well pump is based on centrifugal force and multistage pumping.
Step 1: Motor Starts
When power is supplied, the submersible motor begins to rotate and drives the pump shaft and impellers.
Step 2: Water Enters the Pump
Groundwater enters the pump through the inlet screen at the bottom of the pump.
Step 3: Impellers Generate Centrifugal Force
As the impellers rotate at high speed, they create centrifugal force that pushes water outward from the center of the impeller to the outer edge.
This process increases the velocity and pressure of the water.
Step 4: Multi-Stage Pressure Increase
In deep well pumps, multiple impellers are arranged in stages.
Each stage increases the water pressure step by step, allowing the pump to lift water from significant depths.
Step 5: Water Is Discharged to the Surface
After passing through all stages, the pressurized water flows through the discharge pipe and is delivered to the surface for use.
Advantages of Submersible Well Pumps
Submersible well pumps offer several important advantages:
High efficiency because the pump pushes water rather than pulling it
No priming required
Reduced noise since the pump operates underwater
Lower risk of cavitation
Stable long-term operation
These features make submersible pumps an ideal solution for deep well applications.
Conclusion
A submersible well pump combines a sealed electric motor with a multistage centrifugal pump to efficiently lift groundwater from deep wells. Its compact structure, reliable sealing system, and efficient hydraulic design allow it to operate continuously underwater while delivering stable water supply.
Understanding the structure and working principle of a submersible well pump helps users select the right pump model and ensure long-term efficient operation in various water supply applications.
