Product Overview
The VPPL-022PC5-R00S/20N and VPPL-046PQC-R00S/20N are the 22 cc-class and 46 cc-class models within the Duplomatic VPPL series of medium-pressure open-loop variable displacement axial piston pumps. The VPPL series features a swash plate (oscillating plate) displacement mechanism, where pump flow is proportional to drive speed and swash plate inclination angle, with displacement continuously adjustable from zero to maximum.
The VPPL series is available in seven sizes — 008, 016, 022, 036, 046, 070, and 100 — covering displacements from 8 to 100 cm³/rev for medium-pressure open-circuit hydraulic systems. Sizes 008–046 have a continuous working pressure of 210 bar with peak pressure of 280 bar; sizes 070 and 100 have a continuous working pressure of 280 bar with peak pressure of 315 bar.
Model Code Breakdown (for procurement and engineering reference):
VPPL: Duplomatic medium-pressure open-loop variable axial piston pump series
022 / 046: Displacement size, corresponding to 22 cm³/rev and 46 cm³/rev
PC5: Pressure Compensating control, adjustment range 30–210 bar, for sizes 008–046
PQC: Pressure + flow rate control (load sensing), pressure range 11–190 bar (sizes 008–046), differential pressure range 15–28 bar
R: Clockwise rotation (viewed from shaft end)
00: Mounting flange code, SAE-2 type two-hole flange
S: Port configuration — suction/delivery SAE flange with metric bolts, drain BSP threaded ports
20N: 20 = design series, N = NBR sealing rings for mineral oils
Drop-in Replacement Advantage: Manufactured to exact Duplomatic OEM specifications, these pumps are dimensionally matched for SAE J744 two-hole mounting flange, cylindrical keyed shaft (SAE J744 standard), port layout, and control module interface, achieving complete drop-in interchangeability with the original VPPL series. Every pump undergoes 100% simulated load testing prior to shipment, validating volumetric efficiency and variable displacement response under conditions replicating real-world duty cycles.
Technical Specifications
Model VPPL-022PC5-R00S/20N:
Model Code: VPPL-022PC5-R00S/20N
Series: Duplomatic VPPL (Open Loop, Medium Pressure)
Maximum Displacement: 22 cm³/rev
Continuous Working Pressure: 210 bar
Peak Pressure: 280 bar
Maximum Speed: 2000 rpm
Minimum Speed: 500 rpm
Theoretical Flow at 1500 rpm: 33 L/min
Control Type: PC5 — Pressure Compensating, adjustment range 30–210 bar, approx. 69 bar per screw turn
Rotation: Clockwise (viewed from shaft end)
Mounting Flange: SAE J744 two-hole flange (SAE-2 type)
Shaft: Cylindrical keyed shaft (SAE J744 standard)
Port Connections: Suction/delivery SAE flange with metric bolts; drain BSP threaded ports
Seal Material: NBR (nitrile), suitable for mineral oil-based fluids
Housing Oil Volume: 0.3 dm³
Weight: Approx. 13 kg
Ambient Temperature: -10°C to +50°C
Fluid Temperature: -10°C to +70°C
Recommended Viscosity: 20–50 cSt
Fluid Cleanliness: ISO 4406 18/15/12
Model VPPL-046PQC-R00S/20N:
Model Code: VPPL-046PQC-R00S/20N
Series: Duplomatic VPPL (Open Loop, Medium Pressure)
Maximum Displacement: 46 cm³/rev
Continuous Working Pressure: 210 bar
Peak Pressure: 280 bar
Maximum Speed: 2000 rpm
Minimum Speed: 500 rpm
Theoretical Flow at 1500 rpm: 69 L/min
Control Type: PQC — Pressure + Flow Rate Control (Load Sensing), pressure range 11–190 bar, differential pressure range 15–28 bar, minimum delivery pressure 15 bar
Rotation: Clockwise (viewed from shaft end)
Mounting Flange: SAE J744 two-hole flange
Shaft: Cylindrical keyed shaft (SAE J744 standard)
Port Connections: Suction/delivery SAE flange with metric bolts; drain BSP threaded ports
Seal Material: NBR (nitrile), suitable for mineral oil-based fluids
Housing Oil Volume: 1.0 dm³
Weight: Approx. 23 kg
Ambient Temperature: -10°C to +50°C
Fluid Temperature: -10°C to +70°C
Recommended Viscosity: 20–50 cSt
Fluid Cleanliness: ISO 4406 18/15/12
VPPL Series Displacement Size Reference:
VPPL-008: 8 cm³/rev, 12 L/min @ 1500 rpm, weight approx. 9 kg
VPPL-016: 16 cm³/rev, 24 L/min @ 1500 rpm, weight approx. 13 kg
VPPL-022: 22 cm³/rev, 33 L/min @ 1500 rpm, weight approx. 13 kg
VPPL-036: 36 cm³/rev, 54 L/min @ 1500 rpm, weight approx. 21 kg
VPPL-046: 46 cm³/rev, 69 L/min @ 1500 rpm, weight approx. 23 kg
VPPL-070: 70 cm³/rev, 105 L/min @ 1500 rpm, weight approx. 43 kg
VPPL-100: 100 cm³/rev, 150 L/min @ 1500 rpm, weight approx. 62 kg
Key Technical Advantages
1. Swash Plate Variable Displacement with Stepless Flow Adjustment
The VPPL series employs a swash plate (oscillating plate) variable displacement design, where pump displacement is proportional to swash plate inclination angle and can be continuously adjusted from zero to maximum. The maximum inclination angle can be mechanically limited via an adjustment screw, allowing the maximum flow limit to be set according to system requirements to prevent actuator overspeed. Compared to bent-axis designs, the swash plate configuration is more compact with shorter axial dimensions, ideal for space-constrained installations.
2. PC5 Direct-Operated Pressure Compensator with Constant Pressure Output
The VPPL-022PC5-R00S/20N is equipped with a PC5 pressure compensator, a direct-operated pressure control. When system pressure reaches the setpoint, the compensator automatically reduces pump displacement, maintaining only leakage compensation flow to minimize heat generation and power loss. Adjustment range is 30–210 bar, with approximately 69 bar per adjustment screw turn, providing high adjustment precision and easy operation.
3. PQC Load Sensing Control for Precision Flow Matching
The VPPL-046PQC-R00S/20N features a PQC pressure + flow rate control module (load sensing) that adds flow control on top of the PC5 pressure compensation function. The PQC controller senses the pressure differential (Δp) across a throttle valve installed in the user line and automatically adjusts pump displacement to maintain constant throttle pressure drop, achieving precise flow delivery on demand. Differential pressure adjustment range is 15–28 bar, minimum delivery pressure is 15 bar. In multi-actuator systems, PQC control dramatically reduces throttling losses and system heat generation for significant energy savings.
4. SAE J744 Standard Mounting Interface with Drop-in Interchangeability
The VPPL series is dimensionally matched to the original Duplomatic VPPL specification for SAE J744 two-hole mounting flange (SAE-2 type), cylindrical keyed shaft (SAE J744 standard), and port layout. The SAE-2 flange has a centering diameter of 82.55 mm, providing high standardization that requires no adaptation for replacement, significantly reducing equipment downtime. Suction/delivery ports use SAE flange connections with metric bolts; drain ports use BSP threaded ports (no drain port on size 008).
5. Four Control Options for Flexible Configuration
The VPPL series offers four control types to suit different application requirements: PC* direct-operated pressure control (basic constant pressure), PCR remote pressure control (remote pressure adjustment), PQC pressure + flow rate control (load sensing), and PCX* with external control devices (electrical unloading / proportional pressure control). PCR remote control receives an external pilot valve signal via the X port, with approximately 1.5 L/min available on the X port for remote control and a maximum connection length of 2 m. PCX5 can be paired with a DS3-SA2 solenoid valve for electrical unloading, or with a PRED3 proportional valve for 0–10V/4–20mA stepless electronic pressure control.
Application Areas
Plastics Machinery: Small to medium-tonnage injection molding machine clamp and injection hydraulic systems (injection molding is the most mainstream application for the VPPL series)
Machine Tools: Hydraulic fixtures, hydraulic chucks, CNC machine hydraulic power units, precision test benches
Rubber & Die-Casting Equipment: Rubber injection molding machines, small die-casting machine hydraulic systems
Packaging Machinery: Hydraulic stamping packaging machines, automated packaging line hydraulic actuators
Metallurgical Equipment: Small to medium metallurgical auxiliary equipment hydraulic power sources
Marine & Offshore: Marine deck machinery, small steering gear hydraulic systems
Environmental Equipment: Hydraulically driven fans, hydraulic dust collection systems
Expert Maintenance Tips
1. Hydraulic Fluid Cleanliness
The VPPL series variable control spool and pressure compensator operate with tight clearances and are sensitive to particulate contamination. System fluid cleanliness must meet ISO 4406 18/15/12 requirements. Install a 10 μm absolute-rated filter element at the pump inlet. Replace elements at 500 hours after first commissioning, then every 1,000 operating hours or 6 months, whichever comes first.
2. Case Drain Line Requirements
The case drain line must return directly to the reservoir. Pressure inside the pump housing must never exceed 0.5 bar (relative). The drain line diameter must be adequately sized: for sizes 036 and 046, the drain line must be at least 1/2″; size 008 has no drain port and requires no drain line. The drain outlet must terminate below oil level at all times to prevent air ingestion. Never tie the drain line into the main system return line.
3. Pre-Start Priming Procedure
Before first start, fill the pump housing with clean hydraulic fluid through the uppermost case drain port. After installation, turn the drive shaft by hand several revolutions to confirm free rotation without binding. Start at low speed with zero load and run for 5–10 minutes. Verify continuous bubble-free flow from the case drain. Only then apply load.
4. PC5 Pressure Compensator Setting
Set the VPPL-022PC5-R00S/20N pressure compensator 15–20 bar above the maximum working load pressure, never exceeding the pump’s 210 bar continuous rating. Adjust only with the system at zero load. Rotate the adjustment screw slowly and verify stable pressure gauge readings before proceeding. Each screw turn corresponds to approximately 69 bar of pressure change — adjust in small increments. Never adjust the compensator while the system is under pressure.
5. PQC Load Sensing Valve Adjustment
The VPPL-046PQC-R00S/20N PQC control module requires correct setting of differential pressure and pressure parameters. The differential pressure adjustment range is 15–28 bar and must be matched to the system’s throttle valve characteristics. The connection pipe between the X port and the flow line downstream of the restrictor (or valve) must always be made (customer charge). Minimum delivery pressure is set at 15 bar to ensure stable flow control even under low-load conditions.
