PVV-250 PVV-540 PVWH-45 Variable Displacement Axial Piston Pump

Product Overview

The PVV/PVWH Series Variable Displacement Axial Piston Pumps represent the flagship line of high-horsepower, open-loop hydraulic pumps engineered for the most demanding industrial and mobile applications. Covering the PVV-200, PVV-250, PVV-440, PVV-540, and PVWH-45 models, this series delivers displacements from 200 ml/rev to 540 ml/rev with peak pressures reaching 450–500 bar and power output up to 418 kW.

Every pump undergoes 100% simulated full-load testing before shipment, ensuring that flow-pressure characteristics match the original equipment specification precisely. The cylinder body is constructed from ductile iron, significantly improving contamination resistance and pressure containment compared to conventional cast iron housings. The patented pressure-lubricated swashblock design, combined with polymerous bearings on the integral saddle, enables reliable operation on low-viscosity fluids, high water-content fluids, and fire-resistant hydraulic fluids such as Skydrol™, Stack Magic™, and Erifon™.

For interchangeability, the PVV series supports field-swappable control modules including pressure compensating, electrohydraulic, solenoid-operated volume, and fixed displacement options. The PVWH series offers up to 21 different control types with field interchangeability, allowing control changes without disconnecting the pump from the system piping or drive.

Technical Specifications

PVV-250

• Model: PVV-250

• Theoretical Maximum Displacement: 250 ml/rev (15.26 in³/rev)

• Rated Continuous Pressure: 345 bar (5000 psi)

• Peak Pressure: 400 bar (5800 psi)

• Maximum Speed (Non-Supercharged): 1800 rpm

• Maximum Speed (Supercharged): 2200 rpm

• Rated Flow at 1000 rpm: 58 gpm / 223 lpm

• Rated Flow at 1800 rpm: 109 gpm / 413 lpm

• Control Options: Pressure Compensating / Electrohydraulic / Solenoid Volume / Fixed Displacement

• Mounting: ISO 250 4-Bolt Flange

PVV-540

• Model: PVV-540

• Theoretical Maximum Displacement: 540 ml/rev (33.00 in³/rev)

• Rated Continuous Pressure: 245 bar (5000 psi)

• Peak Pressure: 400 bar (5800 psi)

• Maximum Speed: 1200 rpm

• Rated Flow at 1000 rpm: 129 gpm / 488 lpm

• Rated Flow at 1200 rpm: 155 gpm / 587 lpm

• Weight: 333 kg (734 lbs)

• Mounting: ISO 250 4-Bolt Flange

PVWH-45

• Model: PVWH-45

• Displacement: 98 cc/rev

• Rated Continuous Pressure: 172 bar (2500 psi)

• Peak Pressure: 345 bar

• Maximum Speed: 2700 rpm

• Maximum Flow: 43 gpm (approx. 163 lpm)

• Control: Pressure Compensating

• Mounting: Flange Mount

Key Technical Advantages

1. Patented Pressure-Lubricated Swashblock Design

The PVV series features a patented pressure-lubricated swashblock with polymerous bearings on the integral saddle. System pressure directly supplies lubrication to the swashblock interface, maintaining stable control response under high-cycling operations while enabling reliable performance on low-viscosity and specialty fluids.

2. Ductile Iron Cylinder Body with Contamination Resistance

The cylinder body is manufactured from ductile iron, offering higher tensile strength and fatigue resistance than conventional grey iron. Combined with a replaceable hardened cylinder wear plate and bronze port plate, the pump maintains stable volumetric efficiency and service life even at fluid cleanliness levels of ISO 4406 21/19/16.

3. Quiet Port Plate Design for Reduced Noise

The PVV series incorporates a quiet port plate design that optimizes port slot geometry and transition zone damping characteristics, effectively reducing pressure ripple and fluid-borne noise. The PVWH series further reduces control noise through the use of static O-ring seals in place of traditional gasket seals, while also improving aesthetic design.

4. High Volumetric Efficiency and Long-Life Bearing System

Piston shoes run on a flat steel thrust plate with mechanically retained shoe construction, ensuring no shoe lift-off at high rotational speeds. Cylinder-mounted polymerous journal bearings and a sealed front shaft bearing prevent external contaminant ingress, maintaining volumetric efficiency above 95% under continuous full-load operation.

Application Areas

• Automatic Transmission Test Benches: High-pressure, high-flow capability meets precise flow control requirements for transmission valve body testing

• High-Specification Mobile Equipment: Suitable for heavy-duty travel hydraulic systems in mining and forestry machinery

• Precision Loader and Arm Controls: Pressure-compensating control enables accurate load-sensing operation

• Well-Service Equipment: Hydraulic power units for blender units, injectors, and coiled-tubing equipment

• Subsea ROV Hydraulic Systems: Low-viscosity fluid compatibility suits deep-water operational environments

• Industrial Hydraulic Power Units: Provides stable high-pressure oil supply for large-tonnage presses and injection molding machines

Expert Maintenance Tips

Installation: PVV series pumps support both horizontal and vertical mounting. For horizontal installation, ensure the case drain port faces upward. Before initial startup, the pump case must be filled with clean hydraulic oil to prevent instantaneous wear of the port plate and piston/cylinder group from dry starting.

Fluid Requirements: A kinematic viscosity range of 36–149 cSt is recommended, with an allowable operating range of 12–432 cSt. When using water-containing or phosphate ester fluids, verify that seals are Viton or EPR material; standard Buna-N seals are not compatible with these media.

Operational Monitoring: Pumps should not be operated at neutral (zero displacement) for more than 30 consecutive minutes. For extended hold periods, maintain a minimum 10% stroke to ensure proper lubrication oil circulation within the case. Case drain pressure must not exceed 25 psi (approximately 1.7 bar), as higher pressure will cause shaft seal failure.

Scheduled Maintenance: Every 2,000 operating hours or 12 months (whichever comes first), inspect case drain flow and fluid cleanliness. If drain flow increases by more than 30% from the baseline value, this indicates wear in the piston/cylinder group or port plate, and service should be scheduled promptly. For PVWH series pumps, the manufacturer recommends replacement with PVWJ equivalents to secure long-term spare parts availability and technical support.