How to choose the right SQP single vane pump
The core principles for choosing a TOKIMEC SQP single vane pump (low-noise fixed-displacement tandem vane pump) are: confirm system parameters → match model specifications → verify working condition compatibility → check installation and maintenance requirements. Below is a detailed guide.
1. Confirm Core Parameters (Starting Point of Selection)
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Parameter
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Determination Method
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Key Selection Notes
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Working Pressure
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Measure the maximum and normal operating pressure of the system
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1. The rated pressure of the SQP series is 21 MPa, and the peak pressure is 25 MPa. 2. For continuous operation, keep the working pressure 20%–30% lower than the rated value to extend service life. 3. Select the SQPS high-pressure series for operating pressure above 16 MPa.
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Flow Rate Requirement
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Calculate the maximum required flow: $$Q = \text{Displacement} \times \text{Rotational Speed} \times \text{Efficiency$$
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1. Volumetric efficiency is generally 0.85–0.9. 2. Reserve 10%–20% flow margin to cope with pressure fluctuations. 3. Match the speed requirement of actuators.
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Rotational Speed Range
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Confirm the rated speed of the driving motor
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1. Minimum speed: 600 rpm (to ensure sufficient oil suction). 2. Maximum speed: 1800 rpm for SQP1/SQP2; 1500 rpm for SQP3/SQP4. 3. Recommended operating speed: 800–1400 rpm.
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Power Calculation
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Formula: $$P(\text{kW}) = \dfrac{p(\text{MPa}) \times Q(\text{L/min})}{60 \div \eta$$
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Ensure the motor power is properly matched to avoid overload.
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2. SQP Model Code Explanation
Standard model format: (F3)-SQP(S)3-35-86C(2)-(LH)-18
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Code
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Meaning
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Selection Tips
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Oil type code
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F3 = Phosphate ester fluid; F11 = Water-glycol fluid; No mark = Mineral hydraulic oil
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Select according to the system fluid to prevent seal damage.
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Series code
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SQP = Standard type; SQPS = High-pressure type
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Choose SQPS for high-pressure conditions, and SQP for standard working conditions.
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Pump frame number
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1 / 2 / 3 / 4
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Displacement range increases sequentially: SQP1 (smallest), SQP4 (largest).
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Displacement code
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Numerals (e.g. 10, 14, 21, 35)
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Indicates geometric displacement (mL/r), which determines output flow.
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Mounting type
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86C = Flange mounting; 86D = Foot mounting
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Match the installation space and connection form of equipment.
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Rotation direction
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LH = Left-hand rotation; No mark = Right-hand rotation
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Must be consistent with the rotation direction of the driving motor.
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3. Detailed Selection Procedures
3.1 Select Pump Frame Number (Based on Flow Rate)
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Pump Frame No.
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Displacement (mL/r)
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Applicable Flow (L/min)
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Typical Applications
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SQP1
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2–14
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10–80
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Small machine tools, automated equipment
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SQP2
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10–21
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50–120
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Medium injection molding machines, hydraulic presses
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SQP3
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17–38
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100–200
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Large die-casting machines, construction machinery
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SQP4
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38–80
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200–400
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Heavy-duty hydraulic systems
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3.2 Precise Displacement Matching
Calculation formula: $$\text{Displacement (mL/r)} = \dfrac{\text{Required Flow (L/min)} \times 1000}{\text{Rotational Speed (rpm)} \div \text{Efficiency (0.85–0.9)}$$ Select the standard displacement closest to the calculated value; a slightly larger displacement is preferred.
3.3 Hydraulic Fluid Selection
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Recommended fluid: ISO VG32–VG68 anti-wear hydraulic oil, kinematic viscosity: 20–40 mm²/s.
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Operating temperature: -10 ℃ ~ 50 ℃. A cooling system is required if oil temperature exceeds 60 ℃.
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Special fluids: Choose F11 series for water-glycol fluid, F3 series for phosphate ester fluid.
3.4 Mounting Type Selection
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86C Flange mounting: Compact structure, ideal for limited installation space.
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86D Foot mounting: High stability, suitable for equipment with severe vibration.
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Requirements: Ensure rigid mounting base; use shock-absorbing pads; coaxiality ≤ 0.05 mm.
3.5 Noise Reduction & Service Life Optimization
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The SQP series features a pulse damping structure, with noise 5–10 dB lower than ordinary vane pumps.
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Service life maintenance:
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Keep fluid cleanliness at ISO 18/15; install precision filters.
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Avoid long-term operation under maximum pressure or maximum speed.
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Replace hydraulic oil and filters regularly (recommended every 2000 working hours).
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4. Common Selection Mistakes & Notes
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Ignore either pressure or flow: Insufficient flow slows down actuators; excessive pressure damages seals.
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Mismatched rotational speed: Speed below the minimum value causes oil starvation, cavitation and excessive noise.
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Incorrect hydraulic fluid: Different fluids require dedicated seals; mixed use leads to leakage and severe wear.
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Improper installation: Poor coaxiality or weak base causes vibration, noise and shortened service life.
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No performance margin: Reserve 10%–20% margin for pressure and flow to adapt to fluctuating working conditions.
5. Summary of Selection Process
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Clarify operating requirements: system pressure, flow rate, motor speed, fluid type and working environment.
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Select pump frame number and calculate required displacement according to flow demand.
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Confirm complete model: series type, mounting form, rotation direction and fluid code.
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Verify parameters: ensure pressure, flow and speed are within the allowable range; check motor power.
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Confirm installation dimensions and space availability.
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Purchase genuine products from official authorized suppliers for reliable quality and after-sales service.
