Screw Pump
Pumps & Valves
Screw Pump
1. Product Overview
The screw pump is a positive displacement pump that moves liquid through the volume changes created as one or more meshing screws rotate. Built around a pump casing, a driving screw, driven screw(s), bearings, seals and a drive unit, it handles high-viscosity liquids with a smooth, steady flow.
Typical applications: transfer of high-viscosity media, slurries containing solids, lubricating oils, crude oil and thick food pastes.
Key features: pulse-free, even flow; strong self-priming; reliable handling of high-viscosity liquids; gentle, low-shear treatment of the pumped medium; reversible operation.
2. Working Principle
Driven by the motor, the driving screw rotates and turns the driven screw(s) in synchronous mesh. At the suction end the intermeshing space gradually enlarges, creating a vacuum that draws in the medium. The screw threads then carry the medium axially forward through a continuous series of sealed chambers, while at the discharge end the space progressively decreases and the medium is expelled through the outlet.
3. System Classification
By Number of Screws
| Type | Features | Application Scenarios |
|---|---|---|
| Single screw | Rubber stator, wear-resistant | Solid-laden slurries, high-viscosity media, sewage sludge |
| Twin screw | Two meshing screws, high flow | Lube oil, fuel oil, chemical media |
| Triple screw | Three screws, smooth and quiet | Hydraulic oil, lube oil, heavy fuel oil |
| Five screw | Five screws, high flow, low noise | Marine fuel, large lubrication systems |
By Conveying Medium
| Type | Applicable Media | Stator/Screw Material |
|---|---|---|
| Standard | General oils, chemical liquids | 40Cr screw + cast iron casing |
| Wear-resistant | Solid-laden slurries, sludge | Hard-chrome-plated 40Cr screw + NBR stator |
| Food-grade | Food pastes, syrups | 304 screw + food-grade rubber stator |
| Corrosion-resistant | Corrosive media | 316L screw + FKM stator + lined casing |
4. Detailed Technical Parameters
4.1 Typical Specification Table
| Type | Flow (m³/h) | Discharge Pressure | Speed | Power | Port Size |
|---|---|---|---|---|---|
| Single screw | 0.1～80 | 0.6～2.4MPa | 200～960 | 0.37～30kW | DN20～DN150 |
| Twin screw | 1～500 | 0.6～4.0MPa | 960～2900 | 2.2～200kW | DN25～DN300 |
| Triple screw | 0.5～200 | 0.6～10MPa | 1450～2900 | 1.5～110kW | DN20～DN200 |
Note: The discharge pressure of a single screw pump depends on the number of stages, at approximately 0.6 MPa per stage.
4.2 Design Conditions & Performance Indicators
| Parameter | Specification |
|---|---|
| Pulsation rate | Single screw ≤±5%; Twin/Triple ≤±1% |
| Self-priming height | Single screw up to 8m |
| Solid content allowance | Single screw max approx 40% (vol) |
| Viscosity range | 1～1000000mPa·s |
| Suction vacuum | ≤0.08MPa |
| Noise | ≤80dB(A) (1m from pump) |
4.3 Electrical Parameters
| Applicable Region | Voltage | Frequency |
|---|---|---|
| China/Russia/Central Asia | 380V | 50Hz |
| Middle East/Southeast Asia/Africa | 400V / 415V | 50Hz |
| South Korea | 380V | 60Hz |
| Americas (if needed) | 440V / 480V | 60Hz |
When ordering, please specify your local voltage and frequency.
5. Core Component Selection
| Component | Common Brands | Features & Applications |
|---|---|---|
| Motor | ABB, Siemens | IP55 as standard; VFD and explosion-proof versions available |
| Mechanical seal | John Crane, Burgmann | Single or double seal, selected to suit the medium |
| Stator (single screw) | Premium domestic brands | NBR / FKM / food-grade rubber |
| Screw | Machined to order | Hard-chrome-plated 40Cr / 304 / 316L |
| Bearings | SKF, NSK | Heavy-duty roller bearings |
6. Typical Application Fields
Petrochemical: crude oil and heavy fuel oil transfer, fuel loading and unloading. Environmental: sludge transfer and dewatered sludge feeding. Food: chocolate paste, syrups and jams. Chemical: high-viscosity resins, adhesives and coatings. Paper: pulp and coating transfer.
7. Design Standards & Certifications
| Standard | Description |
|---|---|
| GB/T 10886-2002 | Single screw pump technical conditions |
| API 676 | Positive displacement pump standard |
| ISO 9001:2015 | Quality Management System |
| CE / EAC / GOST-R | Available upon request |
8. Customizable Options
| Option | Details |
|---|---|
| Pump body material | Cast iron / cast steel / 304 / 316L |
| Screw material | 40Cr hard-chrome/304/316L |
| Stator material | NBR/FKM/EPDM/Food-grade rubber |
| Seal type | Packing / single mechanical seal / double mechanical seal |
| Heating jacket | Jacketed casing; steam keeps high-viscosity media at pumping temperature |
| Explosion-proof | Ex-proof motor and instruments |
9. Warranty Terms
| Equipment Status | Warranty Period | Warranty Scope |
|---|---|---|
| New Equipment | 12 Months | Body, screw, stator (excl. normal wear), bearings, seal |
| Refurbished Equipment | 6 Months | Body, screw, stator (excl. normal wear), bearings, seal |
| Idle Equipment (As-is) | 3 Months | Main functional parts |
Note: the single-screw pump stator is a rubber wear part; stator damage caused by normal wear is not covered by free replacement under warranty.
Final warranty terms are as per the contract. Every order includes installation guidance and remote commissioning support.
10. Packaging & Delivery
| Item | Packaging Method |
|---|---|
| Pump Body | Wooden box |
| Motor | Wooden box |
| Coupling/Baseplate | Wooden box |
| Spare stator/accessories | Carton, shipped with main unit |
Container capacity estimate (for reference only; subject to the actual configuration):
Small screw pumps (≤5.5kW): approx. 15～25 units per 20'GP; medium screw pumps (5.5～30kW): approx. 5～10 units per 40'HQ
Installation: on-site installation supervision available.
11. Information Required for Quotation
To receive an accurate quotation, please provide: medium name, concentration, temperature and viscosity; whether solids are present (particle size, concentration, hardness); required flow rate and discharge pressure; suction conditions (self-priming or flooded, liquid level); corrosiveness of the medium; preferred pump type (single/twin/triple screw); material requirements; local voltage and frequency; equipment condition preference (new/refurbished/idle); budget range and brand preference, if any; delivery terms (FOB/CIF/DDP); destination port or delivery address.