A standard twin screw pump uses two intermeshing parallel helical screws counter-rotating inside a close-tolerance double-bore casing — fluid is trapped in sealed axial cavities between screw flights and bore wall, conveyed smoothly from inlet to outlet without turbulence, pulsation, or shear. Processing 0.1–2,000 m³/h at viscosities of 1–2,000,000 cP and pressures up to 100 bar, it simultaneously handles gas-entrained, particle-laden, and multi-phase fluids with constant gentle displacement — the universal positive displacement pump for viscous, sensitive, and mixed-phase process streams.
Two timing-geared screws rotate in opposite directions — the drive screw through the motor coupling and the driven screw through a precision timing gear set outside the product zone. As screw flights unmesh at the inlet, expanding cavities draw fluid in axially. Fluid fills the helical cavities between flights and bore, sealed by the running clearance (0.05–0.2 mm). Screw rotation transports sealed fluid plugs axially to the outlet without radial displacement — generating no centrifugal force, no turbulence, and minimal shear. Discharge is smooth and essentially pulse-free at all speeds from 100 to 3,600 RPM.
Challenges
Running Clearance Sensitivity to Thermal Expansion and Wear
Screw-to-bore clearance (0.05–0.2 mm) tightens on thermal expansion or wear — contact causes seizure in absence of lubrication from process fluid.
Dry-Run Damage Within Seconds of Loss of Prime
Unlike gear pumps, twin screws have no product-lubricated surfaces — dry running destroys timing gears and screw tips within 30–60 seconds.
Slip (Internal Leakage) Increasing Rapidly at Low Viscosity (<10 cP)
At low viscosity, clearance leakage from high-pressure to low-pressure side (slip) increases — volumetric efficiency falls and flow becomes pressure-dependent.
Timing Gear Wear at High Speed and High Differential Pressure
Timing gears transmit high torque at maximum speed and pressure — gear flank wear degrades timing accuracy; screw contact and seizure risk.
Large Footprint vs. Equivalent Gear Pump (Timing Gear Box Adds Length)
External timing gearbox required outside product zone adds significant length and weight vs. equivalent-capacity gear pump.
Solutions
- Dry-Run Protection System (Vibration Sensor + 10-Second Shutdown Interlock): Vibration sensor detects screw contact; PLC trips pump within 10 seconds — before damage threshold.
- Product-Lubricated Screw Surfaces + External Gearbox Isolation: Product lubricates screw tips and bore; timing gear operates in separate oil-lubricated chamber — never in contact with process fluid.
- Speed Reduction via VFD at Low Viscosity (Maintain Screw Tip Speed <3 m/s): Reduced speed lowers slip velocity — partially compensates for viscosity reduction; flow accuracy maintained above 50 cP.
- Hardened Timing Gears (Case-Hardened 60 HRC, Lapped to DIN 5 Accuracy): Case-hardened, precision-ground timing gears rated 20,000 hours service — maintain screw synchronisation under full load.
- Close-Coupled Motor Mounting (Eliminating Coupling and Reducing Footprint by 30%): Close-coupled design eliminates shaft coupling and reduces overall length — compact footprint for skid-mounted applications.
Applications
- Petrochemical & Oil/Gas: Crude oil transfer, bitumen pumping, fuel oil blending, lube oil filling — high viscosity, gas-entrained service.
- Chemical: Polymer melt transfer, resin dosing, adhesive pumping, chemical process fluid circulation.
- Food & Beverage: Chocolate, glucose syrup, honey, molasses, tomato paste, fruit concentrate — high-viscosity gentle transfer.
- Pharmaceutical: Viscous API solution, ointment base transfer, slurry dosing — gentle positive displacement.
- Marine & Power: Fuel oil and heavy oil transfer on ships and power plants — high-pressure viscous fuel service.
Models & Capacities
Type 1A — Standard Twin Screw Pump (Industrial): Models & Capacities | |||||||||||
Model | Scale | Flow Rate [m³/h] | Screw Ø [mm] | Speed [RPM] | Max Press. [bar] | Max Viscosity [cP] | Max Temp. [°C] | Inlet/Outlet Ø [mm] | Motor [kW] | L×W×H [mm] |  |
TSP-025 | Lab/Pilot | 0.1–1.5 | Ø25 | 100–1,800 VFD | 20 | 1,000,000 | 150 | DN 15 | 0.25 | 380×180×200 |  |
TSP-040 | Pilot | 0.3–5 | Ø40 | 100–1,800 VFD | 30 | 1,000,000 | 150 | DN 25 | 0.55 | 480×220×250 |  |
TSP-063 | Pilot | 1–15 | Ø63 | 100–1,800 VFD | 50 | 1,000,000 | 180 | DN 40 | 1.1 | 620×280×320 |  |
TSP-080 | Production | 2–30 | Ø80 | 100–1,800 VFD | 60 | 1,000,000 | 180 | DN 50 | 2.2 | 760×340×390 |  |
TSP-100 | Production | 5–60 | Ø100 | 100–1,800 VFD | 70 | 1,000,000 | 180 | DN 65 | 3.0 | 920×410×470 |  |
TSP-125 | Production | 8–100 | Ø125 | 100–1,800 VFD | 80 | 1,000,000 | 180 | DN 80 | 4.0 | 1,100×490×560 |  |
TSP-160 | Production | 15–180 | Ø160 | 100–1,600 VFD | 80 | 1,000,000 | 200 | DN 100 | 5.5 | 1,320×590×675 |  |
TSP-200 | Production | 30–350 | Ø200 | 100–1,450 VFD | 80 | 1,000,000 | 200 | DN 125 | 7.5 | 1,580×700×810 |  |
TSP-250 | Production | 60–650 | Ø250 | 100–1,200 VFD | 80 | 1,000,000 | 200 | DN 150 | 11 | 1,900×840×970 |  |
TSP-315 | Large Prod | 120–1,200 | Ø315 | 100–1,000 VFD | 80 | 1,000,000 | 200 | DN 200 | 18.5 | 2,280×1,010×1,160 |  |
TSP-400 | Large Prod | 250–2,200 | Ø400 | 80–800 VFD | 80 | 1,000,000 | 200 | DN 250 | 30 | 2,750×1,220×1,400 |  |
TSP-500 | Large Prod | 400–3,500 | Ø500 | 60–650 VFD | 60 | 1,000,000 | 200 | DN 300 | 45 | 3,300×1,470×1,680 |  |