Between Bearings Pump vs. Overhung Pump: Key Differences Explained

 

Pumps are the backbone of many industrial processes, ensuring fluid transport in applications ranging from chemical processing to water treatment. Among the most common types are Between Bearings Pumps and Overhung Pumps. While both serve similar purposes, their design, performance, and applications vary significantly. Understanding these differences helps engineers and operators choose the right pump for their specific needs.

What is a Between Bearings Pump?

A Between Bearings Pump is a centrifugal pump designed with the shaft supported by bearings on both sides of the impeller. This configuration ensures high stability and reduces shaft deflection, making it suitable for heavy-duty applications.

Key Features of Between Bearings Pumps:

• Shaft supported by bearings on both sides

• High stability and reduced vibration

• Can handle high-flow and high-pressure applications

• Often used in chemical, petrochemical, and power industries

This type of pump is ideal for applications requiring longer shaft life, smooth operation, and the ability to manage large volumes of fluid with minimal maintenance.

What is an Overhung Pump?

An Overhung Pump is a centrifugal pump where the impeller is mounted on the shaft supported by bearings on only one side. This makes the pump more compact but less robust compared to between bearings designs.

Key Features of Overhung Pumps:

• Impeller mounted on one end of the shaft

• Bearings located on only one side

• Compact and lightweight design

• Suitable for moderate flow and pressure applications

Overhung pumps are often used where space is limited and the fluid load is moderate, such as in water treatment plants, HVAC systems, and light chemical processes.

Design Differences Between Between Bearings and Overhung Pumps

The primary difference lies in the shaft support and stability:

Feature	Between Bearings Pump	Overhung Pump
Shaft Support	Bearings on both sides of impeller	Bearings on one side only
Shaft Length	Longer and robust	Shorter and less robust
Vibration & Deflection	Minimal	Higher risk of deflection
Maintenance	Slightly more complex	Easier due to compact design
Flow & Pressure Capacity	High	Moderate
Applications	Heavy-duty industries	Light to medium industries

The dual bearing support in Between Bearings Pumps reduces wear and tear on the shaft, which is crucial for long-term reliability in demanding applications.

Vertically Suspended Pump Option

An interesting variation in pump design is the Vertically Suspended Pump, often used in conjunction with between bearings setups in deep sump applications.

Advantages of Vertically Suspended Pumps:

• Space-saving design: Pump is suspended vertically over a sump or pit

• Handling large volumes: Suitable for deep well pumping and condensate extraction

• Reduced floor footprint: Ideal for industrial setups with limited space

• Longer shaft life: Bearings and shaft design reduce deflection

This design is particularly advantageous in power plants, mining, and chemical industries, where space constraints and heavy-duty operation are common.

Applications: Choosing the Right Pump

Between Bearings Pump Applications:

• Petrochemical and chemical processing

• Oil & gas pipelines

• Power generation and cooling systems

• Large industrial water pumping

Overhung Pump Applications:

• Light chemical processing

• HVAC and water circulation

• Food and beverage industry

• General industrial use with moderate flow

The choice between these pumps depends on flow requirements, space availability, and operational load. For high-capacity and high-pressure needs, Between Bearings Pumps are preferred. For smaller, compact, and moderate flow systems, Overhung Pumps offer a cost-effective and efficient solution.

Maintenance Considerations

• Between Bearings Pumps: Require careful alignment and periodic bearing lubrication. They have longer lifespan but more complex maintenance.

• Overhung Pumps: Easier to maintain due to simpler design but may experience faster wear under heavy-duty operations.

• Vertically Suspended Pumps: Require proper shaft alignment and regular inspection of the suspended bearings to ensure optimal performance.

Proper maintenance ensures reliability, prevents downtime, and maximizes the lifespan of all pump types.

Conclusion

Understanding the differences between Between Bearings Pumps and Overhung Pumps is essential for making the right industrial pump choice. Between bearings designs excel in high-pressure, high-flow, and heavy-duty applications due to their stability and durability. Overhung pumps are ideal for moderate conditions, compact installations, and cost-sensitive projects.

The addition of Vertically Suspended Pump adds flexibility for deep sump applications, providing both space efficiency and operational reliability. By considering factors such as flow, pressure, space, and maintenance requirements, industries can select the optimal pump design to improve performance and ensure long-term efficiency.

Choosing the right pump isn’t just about moving fluids—it’s about ensuring safety, reliability, and efficiency in your industrial process.