PGP031 Parker Hydraulic Gear Pump | 16-65cc 207 bar Cast Iron

Product Overview

The PGP031, PGP051, PGP315, PGP330, PGP350, PGP365, and PGP502 are core models of the Parker Hannifin PGP series fixed-displacement external gear pumps, spanning multiple Parker gear pump product platforms.

PGP031 and PGP051 belong to Parker’s Commercial cast iron roller bearing pump series. PGP031 offers displacements from 16.2 to 64.6 cc/rev, while PGP051 covers 21 to 105 cc/rev. Both feature three-piece cast iron construction and roller bearing design for exceptional contamination resistance and durability.

PGP315, PGP330, PGP350, and PGP365 belong to Parker’s PGP300 Series cast iron bushing pumps, featuring three-piece cast iron construction and low-friction bushing design. Continuous operating pressure reaches 241 bar (3,500 psi) with peak pressures up to 275 bar (4,000 psi) . The four models cover distinct displacement ranges: PGP315 (7.6 – 40.6 cc/rev), PGP330 (16.2 – 65.0 cc/rev), PGP350 (21 – 105 cc/rev), and PGP365 (44.3 – 147.5 cc/rev).

PGP502 belongs to Parker’s PGP500 Series aluminum gear pumps and is the smallest frame size in the series. Displacements range from 0.8 to 8 cc/rev. The 9-tooth gear profile delivers exceptionally low noise operation. The high-strength aluminum housing provides maximum working pressure up to 280 bar.

All models are engineered as direct OEM-replacement solutions, fully complying with Parker original design standards and SAE/ISO/DIN mounting interface specifications, offering 100% direct interchangeability with OEM pumps. Every unit undergoes 100% workload simulation testing prior to shipment, rigorously validating pressure retention, volumetric efficiency, and internal leakage performance to meet or exceed OEM standards.

Technical Specifications 

PGP031 Series

• Series: Parker Commercial Cast Iron Roller Bearing Pump

• Displacement Range: 16.2 – 64.6 cc/rev (0.985 – 3.94 in³/rev)

• Maximum Continuous Pressure: 207 bar (3,000 psi)

• Maximum Speed: 2,400 rpm

• Maximum Flow: 38.4 GPM (145.4 L/min)

• Housing Material: High-strength cast iron

• Bearing Type: Roller bearings

• Construction: Three-piece cast iron

• Rotation: CW / CCW / Bi-Rotational

• Volumetric Efficiency: Up to 95%

• Max Weight: 17 kg

• Mounting Standards: SAE / ISO / DIN

PGP051 Series

• Series: Parker Commercial Cast Iron Roller Bearing Pump

• Displacement Range: 21 – 105 cc/rev (1.275 – 6.375 in³/rev)

• Maximum Continuous Pressure: 207 bar (3,000 psi)

• Maximum Speed: 2,400 rpm

• Maximum Flow: 63 GPM (238.5 L/min)

• Housing Material: High-strength cast iron

• Bearing Type: Roller bearings

• Construction: Three-piece cast iron

• Rotation: CW / CCW / Bi-Rotational

• Volumetric Efficiency: Up to 95%

• Max Weight: 22.5 kg

• Mounting Standards: SAE / ISO / DIN

PGP315 Series

• Series: Parker PGP300 Series Cast Iron Bushing Pump

• Displacement Range: 7.6 – 40.6 cc/rev (0.465 – 2.48 in³/rev)

• Maximum Continuous Pressure: 241 bar (3,500 psi)

• Peak Pressure: 275 bar (4,000 psi)

• Maximum Speed: 3,000 rpm

• Maximum Flow: 32 GPM (121 L/min)

• Housing Material: High-strength cast iron

• Bearing Type: Low-friction bushings

• Construction: Three-piece cast iron

• Max Weight: Approx. 15.2 kg

• Mounting Standards: SAE / ISO / DIN

PGP330 Series

• Series: Parker PGP300 Series Cast Iron Bushing Pump

• Displacement Range: 16.2 – 65.0 cc/rev (0.99 – 3.97 in³/rev)

• Maximum Continuous Pressure: 241 bar (3,500 psi)

• Peak Pressure: 275 bar (4,000 psi)

• Maximum Speed: 3,000 rpm

• Maximum Flow: 40 GPM (151 L/min)

• Housing Material: High-strength cast iron

• Bearing Type: Low-friction bushings

• Construction: Three-piece cast iron

• Max Weight: 19 kg

• Mounting Standards: SAE / ISO / DIN

PGP350 Series

• Series: Parker PGP300 Series Cast Iron Bushing Pump

• Displacement Range: 21 – 105 cc/rev (1.275 – 6.375 in³/rev)

• Maximum Continuous Pressure: 241 bar (3,500 psi)

• Peak Pressure: 275 bar (4,000 psi)

• Maximum Speed: 3,000 rpm

• Maximum Flow: 66 GPM (250 L/min)

• Housing Material: High-strength cast iron

• Bearing Type: Low-friction bushings

• Construction: Three-piece cast iron

PGP365 Series

• Series: Parker PGP300 Series Cast Iron Bushing Pump

• Displacement Range: 44.3 – 147.5 cc/rev (2.7 – 9.0 in³/rev)

• Maximum Continuous Pressure: 241 bar (3,500 psi)

• Peak Pressure: 275 bar (4,000 psi)

• Maximum Speed: 2,400 rpm

• Maximum Flow: 93.5 GPM (354 L/min)

• Housing Material: High-strength cast iron

• Bearing Type: Low-friction bushings

• Construction: Three-piece cast iron

• Max Weight: 32 kg

• Mounting Standards: SAE / ISO / DIN

• Thru-Drive Capability: Yes

PGP502 Series

• Series: Parker PGP500 Series Aluminum Gear Pump

• Displacement Range: 0.8 – 7.9 cc/rev

• Maximum Continuous Pressure: Up to 280 bar

• Maximum Speed: 4,000 – 5,000 rpm

• Housing Material: High-strength aluminum

• Gear Profile: 9-tooth gear design

• Rotation: CW / CCW / Bi-Rotational

• Operating Temperature Range: -15℃ to +80℃

• Mounting Standards: SAE / ISO / DIN

Key Technical Advantages

1. Comprehensive Series Coverage for Flexible Selection
From the PGP502 aluminum small-displacement pump (0.8 cc/rev) to the PGP365 cast iron large-displacement pump (147.5 cc/rev), the PGP series offers near-complete displacement coverage. Whether for precision hydraulic systems or heavy-duty construction equipment, the right displacement is available.

2. High-Strength Cast Iron / Aluminum Housing for Diverse Applications
PGP031/051/315/330/350/365 feature high-strength cast iron housings with exceptional contamination resistance and durability, ideal for heavy-duty and harsh environments. PGP502 features a high-strength aluminum housing, delivering lightweight construction without compromising structural integrity.

3. Pressure-Balanced Thrust Plates with Low-Friction Bushings / Roller Bearings
PGP031/051 series utilize roller bearings and pressure-balanced thrust plates to minimize friction and leakage. PGP300 series employ low-friction bushings and balanced thrust plates with internal channels for continuous bushing lubrication. PGP502 features a 9-tooth gear profile for exceptionally low noise operation.

4. Superior High-Pressure Performance
PGP300 series deliver continuous operating pressure up to 241 bar (3,500 psi) with peak pressures of 275 bar (4,000 psi) . PGP502 series reach up to 280 bar. High-strength materials and precision machining ensure long-term stability under high-pressure conditions.

5. Flexible Configuration and Integration Capability
All series support single, tandem, and multiple pump configurations. A wide range of mounting options (SAE, ISO, DIN) and shaft types are available. Optional integrated valves include pressure relief, load sensing unloading, and priority flow dividers.

6. 100% Factory Tested & Direct Interchangeability
Every unit undergoes 100% workload simulation testing prior to shipment, covering pressure retention verification, internal leakage detection, and flow validation. Fully compliant with Parker original design standards, with flange dimensions, shaft specifications, and mounting interfaces identical to OEM pumps—direct drop-in replacement with zero modifications required.

Application Areas

PGP031 / PGP051

• Vocational Vehicles: Tire trucks, salt and sand spreaders

• Aerial Equipment: Aerial lifts

• Oil & Gas: Oil and gas service trucks

• Material Handling, Turf Care, Agriculture, Construction Equipment

PGP315 / PGP330 / PGP350 / PGP365

• Material Handling Equipment

• Turf Care Equipment

• Agricultural Machinery

• Construction Equipment

• Supports multi-section configurations with up to 6 pump sections

PGP502

• Mobile Hydraulic Equipment

• Industrial Hydraulic Systems

• Precision Hydraulic Control Applications

• Agricultural and Construction Machinery Auxiliary Systems

Expert Maintenance Tips

1. Model Confirmation
PGP031, PGP051, PGP315, PGP330, PGP350, PGP365, and PGP502 belong to different product platforms with distinct displacement ranges and pressure ratings. Before installation, confirm the correct series and displacement based on system flow and pressure requirements, and verify the complete model code on the pump nameplate.

2. Rotation Direction Confirmation
PGP series support clockwise (CW) , counterclockwise (CCW) , and bi-rotational configurations. Before installation, always verify that the PTO rotation direction of the host machine matches the pump’s rotation direction—incorrect rotation will result in pump failure to prime and may cause severe damage to gears and bearings within a short period.

3. Installation Precautions

• Thoroughly clean the mounting flange and shaft mating surfaces before installation to ensure no debris remains

• Use Parker-specified torque values for mounting bolts—avoid over-tightening which may cause housing distortion

• PGP300 series feature three-piece cast iron construction—ensure proper alignment of all components

• Ensure correct connection of inlet, outlet, and drain ports

• Direct drive with flexible coupling is recommended—avoid subjecting the pump to axial or radial loads

4. First Start-Up and Bleeding

• Before first start-up, fill the pump with hydraulic oil through the inlet port—never start dry

• After start-up, run at low speed with no load for 2–3 minutes to ensure complete air evacuation from the system

• Check for abnormal noise or leakage

5. Fluid and Filtration

• Use high-quality anti-wear hydraulic oil compliant with DIN 51524 standards

• PGP series are compatible with standard hydraulic fluids, phosphate-ester, and water-glycol

• Maintain system oil cleanliness to ISO 4406 18/15 or better

• Operating temperature should be maintained within -20℃ to +80℃

• Viscosity range: 50 – 7500 SUS

6. Periodic Maintenance

• Check mounting bolt torque every 1,000 operating hours

• Regularly monitor system operating pressure—PGP300 series not to exceed 241 bar (275 bar peak)

• Regularly inspect and replace shaft seals to prevent leakage

• If flow output decreases, noise levels increase abnormally, or system temperature rises excessively, inspect and replace worn components promptly