A rotary screw pump is a type of positive displacement pump that uses intermeshing helical screws (rotors) to move fluid or gas efficiently. These pumps are known for their smooth flow, high efficiency, and ability to handle viscous, abrasive, or sensitive media. They are widely used in industrial, hydraulic, and vacuum applications.
Single-Screw Pump (Progressive Cavity Pump)
Uses a single metal rotor turning inside a stator (elastomer lining).
Ideal for slurries, viscous fluids, and shear-sensitive liquids (e.g., wastewater, food products).
Twin-Screw Pump
Two parallel screws rotate in opposite directions (timing gears prevent contact).
Handles clean and abrasive fluids (e.g., oil, fuel, chemicals).
Triple-Screw Pump
One driving rotor meshes with two idler rotors.
Best for high-pressure hydraulic oil & lubricating fluids.
Dry Screw Vacuum Pump (No oil/liquid inside)
Used for oil-free vacuum generation in semiconductor, chemical, and pharmaceutical industries.
Twin/Triple Screw Pumps:
Rotors rotate, creating sealed cavities that move fluid axially.
Fluid enters the suction side and is pushed toward the discharge.
No metal-to-metal contact (timing gears synchronize rotation).
Single-Screw (Progressive Cavity) Pumps:
The rotor’s eccentric motion creates progressing cavities that trap and move fluid.
✔ Smooth, Low-Pulsation Flow – Ideal for precision applications.
✔ Handles High Viscosity & Abrasives – Works with oils, polymers, and slurries.
✔ Self-Priming – Can evacuate air and start pumping without manual priming.
✔ High Efficiency – Maintains performance even with thick fluids.
✔ Low Maintenance – Fewer wear parts than piston or gear pumps.
Oil & Gas: Crude oil transfer, fuel injection, lubrication systems.
Chemical Processing: Pumping solvents, resins, acids.
Marine: Fuel transfer, bilge pumping.
Food & Beverage: Chocolate, syrups, dairy products.
HVAC & Refrigeration: Chiller systems.
Vacuum Technology: Dry screw pumps for clean processes.
| Feature | Rotary Screw Pump | Gear Pump | Centrifugal Pump | Piston Pump |
|---|---|---|---|---|
| Flow Consistency | Smooth, pulsation-free | Pulsating | Unstable at low flow | High pulsation |
| Viscosity Handling | Excellent (1–1M cP) | Good (up to 100k cP) | Poor (<500 cP) | Good |
| Pressure Capability | Medium-High (up to 300 bar) | Medium (up to 200 bar) | Low-Medium | Very High (700+ bar) |
| Maintenance | Low (non-contact rotors) | Medium (gear wear) | High (seal issues) | High (seals, valves) |
❌ Higher initial cost than gear or centrifugal pumps.
❌ Not ideal for very low-viscosity fluids (e.g., water) unless specially designed.
❌ Precision manufacturing required to maintain rotor clearances.
Colfax (IMO Pump)
Sulzer
KSB
Flowserve
NETZSCH
Rotary screw pumps are versatile, efficient, and reliable for handling viscous, abrasive, or sensitive fluids. They are preferred in industries requiring high-pressure, low-pulsation flow, such as oil & gas, chemicals, and food processing.
The above content was compiled and published by Zhilong Oil Drum Pump Supplier.