How Centrifugal Pumps Work

Converting rotational energy into fluid flow and pressure.
A centrifugal pump is a dynamic machine that uses a rotating impeller to increase the velocity and pressure of a fluid. It is the most common pump type due to its simplicity, efficiency, and ability to handle large volumes. EKG Malaysia specializes in the application, installation, and maintenance of these pumps across all industries.

The Working Principle (Step-by-Step):

1. Priming: The pump casing and suction line are filled with liquid. Most centrifugal pumps must be primed to start.

2. Impeller Rotation: An electric motor (or other driver) spins the impeller at high speed inside the volute casing.

3. Centrifugal Force Creation: The rotating impeller blades impart kinetic energy to the fluid, throwing it outward from the impeller eye (center) to the periphery by centrifugal force.

4. Velocity to Pressure Conversion: The high-velocity fluid enters the expanding volute casing (diffuser area). This design converts the kinetic energy (velocity) into pressure energy (head).

5. Discharge: The pressurized fluid exits through the discharge nozzle.

6. Suction Creation: As fluid is thrown outward, a region of lower pressure is created at the impeller eye. This draws more fluid from the suction line into the pump, creating a continuous flow.

Key Components & Their Functions:

• Impeller: The rotating heart of the pump. Its design (open, closed, semi-open) and diameter determine pump performance.

• Volute Casing: The stationary outer shell that collects the fluid from the impeller and guides it to the discharge, converting speed to pressure.

• Shaft: Transmits torque from the motor to the impeller.

• Shaft Seal (Mechanical Seal or Gland Packing): Prevents fluid from leaking out where the shaft enters the casing.

• Bearings: Support the shaft and impeller, allowing smooth rotation.

• Suction & Discharge Nozzles: Connection points to the piping system.

The Performance Curve:
A centrifugal pump's capabilities are defined by its performance curve, which shows the relationship between:

• Flow Rate (Q)

• Head Pressure (H)

• Power Consumption (P)

• Efficiency (η)
  The pump operates where its H-Q curve intersects the system curve (the resistance of the piping network).

Why Understanding This Matters for Your System:

• Correct Selection: Ensures the pump matches your flow and pressure needs.

• Efficient Operation: Running the pump near its Best Efficiency Point (BEP) saves energy and reduces wear.

• Problem Diagnosis: Understanding the principle helps troubleshoot issues like cavitation (low suction pressure) or overloading.

From principle to practice.
Expert application of this fundamental principle is what ensures reliable, efficient pumping systems.

Contact EKG Malaysia for expert centrifugal pump solutions. We apply this engineering knowledge to select, install, and maintain the right pump for your specific system requirements.