Screw Pump: Parts, Working, Types, Advantages, Disadvantages, and Applications

Published: 28 Dec 2025

In this article, we will discuss what a screw pump is, its parts and their functions, working, advantages, disadvantages, and applications. This guide provides a comprehensive overview of screw pumps and their role in various industries.

What is Screw Pump

A screw pump is a positive displacement pump that uses one or more screws to move fluid in a steady, continuous flow. The screws rotate within a closely fitted chamber, directing the fluid along the screw path. These pumps are designed to handle high-viscosity fluids, maintain smooth, uninterrupted flow, and operate efficiently under high-pressure conditions.

Screw Pump Parts Name and Their Functions

Here are the main parts of a screw pump and what each part does:

1. Screws/Rotors:

The screws are the heart of the pump, responsible for moving fluid along the screw threads. They trap fluid in cavities and push it from the inlet to the outlet.

2. Stator:

The stator works with the screws to form sealed cavities, ensuring smooth and continuous fluid flow. It also helps maintain pressure and prevents backflow.

3. Housing:

The housing encases the screws and stator, providing structural support and guiding the fluid along the pump path. It protects the internal components from damage.

4. Seals:

Seals prevent leaks and maintain the required pressure during pump operation. They are essential for efficiency and for avoiding contamination of the pump fluid.

5. Bearings:

Bearings support the screws and reduce friction during rotation. This improves pump efficiency, stability, and extends the overall lifespan of the components.

6. Timing Gear:

The timing gear synchronizes the movement of multiple screws in multi-screw pumps. It ensures smooth operation and prevents interference between screws.

7. Pressure Relief Valve:

The pressure relief valve protects the pump from excessive pressure. It ensures safe operation and prevents damage to the pump or connected piping.

8. Driving Shaft:

The driving shaft transfers power from the motor to the screws. It is critical for converting rotational motion into fluid movement.

9. Casing:

The casing forms the outer shell of the pump and contains the fluid. It provides structural integrity and protects the pump from external impacts.

Screw Pump Working

As the screws rotate, they trap a fixed volume of fluid in the cavities formed between the screws and the casing. The fluid is then pushed steadily from the inlet to the outlet. This ensures continuous, pulse-free flow, even with high-viscosity fluids. Smooth movement minimizes turbulence and shear, making screw pumps ideal for handling sensitive liquids like oils, syrups, and chemical solutions. Depending on the number of screws, these pumps can handle varying pressures, flow rates, and efficiencies. Their quiet and reliable operation makes them suitable for diverse industrial applications.

Types of Screw Pumps

Here are some common types of screw pumps used in various industries.

1. One-Screw Pump:

Also known as a single screw or progressive cavity pump, it uses one rotating screw and a stationary stator to move fluid. The design creates continuous cavities that transport fluid smoothly from inlet to outlet. It is ideal for handling viscous fluids, slurries, and fluids with solids. This pump is commonly used in the wastewater treatment, food processing, and chemical industries.

2. Two-Screw Pump:

Twin screw pumps feature two intermeshing screws that rotate in opposite directions, providing a non-pulsating and continuous flow. They can handle fluids of varying viscosities, including shear-sensitive liquids. These pumps are widely used in the oil and gas, food, beverage, and pharmaceutical industries due to their gentle pumping action and high efficiency.

3. Three-Screw Pump:

Triple screw pumps consist of one central driving screw and two driven screws, creating smooth and precise fluid movement. They handle high-pressure applications efficiently while minimizing pulsation. This type is often used in lubrication systems, fuel transfer, and hydraulic applications in industrial and marine settings.

4. Five-Screw Pump:

Five-screw pumps use a central rotor surrounded by four driven screws, providing highly uniform, pulse-free flow. They are suitable for large-scale industrial processes where high flow rates and efficiency are required. These pumps are often applied in petrochemical, oil refining, and high-pressure hydraulic systems for reliable fluid transfer.

Advantages of Screw Pump

Screw pumps offer many good features:

They give a smooth and steady flow with no pulses.
They handle thick and dirty fluids easily.
They make very little noise during operation.
They work well at high pressure and at high speeds.

Disadvantages of Screw Pump

There are a few downsides to note:

They can cost more than simple pumps.
Their screws can wear out over time.
They need clean fluid in some applications to avoid damage.

Applications of Screw Pump

These are some common applications of screw pumps:

It safely handles corrosive and abrasive fluids in chemical and petrochemical processes.
It provides gentle and hygienic handling of syrups, sauces, and chocolate in food and beverage applications.
It efficiently transfers fuel, pumps bilge water, and manages ballast in marine operations.
It supports the lubrication systems for turbines and handles fuel for power generation.
It effectively moves sludge, slurry, and other viscous fluids in water and wastewater treatment.

Conclusion

In conclusion, this article covered what a screw pump is, its parts and their functions, working, advantages, disadvantages, and applications in detail. We hope you found it helpful.