PGP030 PGP031 PGP050 PGP051 Parker Hydraulic Gear Pump 3000 psi

Product Overview

The Parker PGP/PGM 030/031/050/051/075/076 Series represents Parker Hannifin’s Commercial Hydraulics brand of high-performance cast iron, external gear fixed displacement pumps and motors. Engineered specifically for truck, construction, and vocational mobile hydraulic applications, this product family features high-strength gray cast iron construction, roller bearing design, and balanced thrust plates as its core technological hallmarks.

The PGP030/031 (small displacement segment) offers displacements from 16.2 to 64.6 cc/rev, ideal for low-flow, high-pressure requirements in compact spaces. The PGP050/051 (medium displacement segment) covers 21 to 105 cc/rev with flow rates up to 63 GPM (238.5 L/min). The PGP075/076 (large displacement segment) extends displacement from 50 to 202 cc/rev with flow rates up to 121.4 GPM (459.5 L/min), meeting the demands of heavy-duty equipment.

The series supports single, tandem, and multiple pump configurations with the ability to stack multiple sections. As original Parker products, these pumps offer direct interchangeability with equivalent series models, with fully compatible mounting dimensions and port interfaces — requiring no system modifications for replacement.

Technical Specifications 

PGP030/031 Series (Small Displacement Segment):

• Brand: Parker Hannifin — Commercial Hydraulics

• Series: PGP030 / PGP031

• Pump Type: Three-piece cast iron, external gear, fixed displacement pump

• Displacement Range: 16.2 – 64.6 cm³/rev (0.99 – 3.94 in³/rev)

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

• Maximum Speed: 2,400 RPM

• Maximum Flow Rate: 41 GPM (155 L/min)

• Volumetric Efficiency: Up to 95%

• Body Material: High-strength gray cast iron

• Bearing Type: Roller bearings

• Configuration: Single / Tandem / Multiple

• Rotation Direction: Clockwise / Counter-clockwise / Bi-Rotational

• Mounting: SAE 2-bolt or 4-bolt flange

• Port Connections: BSPP, Metric Split Flange, SAE Straight Thread, Split Flange

• Seal Material: NBR (standard)

• Compatible Fluids: Mineral oil

• Fluid Temperature: Up to 180°F (approx. 82°C)

• Viscosity Range: 50 – 7,500 SUS

• Weight: Approx. 15 kg (33 lbs, with 1″ gear)

PGP050/051 Series (Medium Displacement Segment):

• Brand: Parker Hannifin — Commercial Hydraulics

• Series: PGP050 / PGP051

• Pump Type: Three-piece cast iron, external gear, fixed displacement pump

• Displacement Range: 21 – 105 cm³/rev (1.28 – 6.38 in³/rev)

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

• Maximum Speed: 2,400 RPM

• Maximum Flow Rate: 63 GPM (238.5 L/min)

• Volumetric Efficiency: Up to 95%

• Body Material: High-strength gray cast iron

• Bearing Type: Roller bearings

• Configuration: Single / Tandem / Multiple

• Rotation Direction: Clockwise / Counter-clockwise / Bi-Rotational

• Mounting: SAE 2-bolt or 4-bolt flange

• Port Connections: SAE, ISO, NPT, BSPP, ODT

• Seal Material: NBR (standard)

• Compatible Fluids: Standard hydraulic fluids, phosphate-ester

• Fluid Temperature Range: -20°C to +80°C

• Viscosity Range: 50 – 7,500 SUS

• Weight: 22.5 kg (50 lbs) max

PGP075/076 Series (Large Displacement Segment):

• Brand: Parker Hannifin — Commercial Hydraulics

• Series: PGP075 / PGP076

• Pump Type: Three-piece cast iron, external gear, fixed displacement pump

• Displacement Range: 50 – 202 cm³/rev (3.07 – 12.3 in³/rev)

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

• Maximum Speed: 2,400 RPM

• Maximum Flow Rate: 121.4 GPM (459.5 L/min)

• Volumetric Efficiency: Up to 95%

• Body Material: High-strength gray cast iron

• Bearing Type: Roller bearings

• Configuration: Single / Tandem / Multiple

• Rotation Direction: Clockwise / Counter-clockwise / Bi-Rotational

• Mounting: SAE 2-bolt or 4-bolt flange

• Port Connections: SAE, ISO, NPT, BSPP, ODT

• Seal Material: NBR (standard)

• Compatible Fluids: Standard hydraulic fluids, fire-resistant fluids

• Fluid Temperature Range: -20°C to +80°C

• Viscosity Range: 50 – 7,500 SUS

• Weight: 42 kg (92 lbs) max

Key Technical Advantages

1. Three-Piece Cast Iron Construction — The Foundation of High-Pressure Durability

The three-piece gray cast iron construction delivers superior fatigue strength, impact resistance, and thermal stability compared to aluminum alloy alternatives. Cast iron’s thermal expansion coefficient closely matches that of the gear materials, maintaining stable clearances at elevated temperatures (up to 80°C) and ensuring reliable continuous operation at up to 207 bar (3,000 psi).

2. Roller Bearings — Long Life & Superior Contamination Resistance

Roller bearing construction provides higher radial load capacity and superior contamination resistance compared to traditional journal bearings. In severe operating environments such as mining, construction, and municipal applications where particulate contamination is prevalent, the roller bearing design effectively extends product service life and reduces maintenance frequency.

3. Balanced Thrust Plates — The Key to High Efficiency & Low Leakage

Balanced thrust plates automatically compensate for axial clearance through hydraulic balancing principles, effectively minimizing internal leakage. This design achieves volumetric efficiency of up to 95% under standard conditions — significantly outperforming competitive products.

4. Flexible Multiple Configuration & Integrated Valve Capability

Support for single, tandem, and multiple configurations with the ability to stack multiple sections. Parker offers extensive integrated valve options — including relief valves, anti-cavitation valves, priority flow controls, unloader valves, accumulator charge valves (single and dual), two-speed valves (winches/ground drives), and load-sense priority flow dividers — directly integrated into the pump housing. This integration reduces external valve counts, eliminates hoses and fittings (and their associated leak points), and lowers system assembly costs.

5. Bi-Rotational Capability & Broad Operating Range

Available in clockwise, counter-clockwise, and bi-rotational configurations to accommodate diverse equipment and mounting orientations. Viscosity range from 50 to 7,500 SUS with compatibility for mineral oils and phosphate-ester fluids. Operating speed from 900 RPM minimum to 2,400 RPM maximum, covering a wide range of applications from low-speed high-torque to high-speed high-flow requirements.

Application Areas

• Dump Trucks — Body hoist hydraulic systems

• Roll-Off Trucks — Container handling hydraulic systems

• Moving Floor Trucks — Unloading conveyor hydraulic systems

• Refuse Trucks — Compaction and ejection mechanisms

• Street Sweepers & Salt/Sand Spreaders — Municipal maintenance equipment

• Aerial Lift Platforms — Elevation and leveling hydraulic systems

• Agricultural Machinery — Tractor hydraulics, combine harvesters

• Construction Equipment — Loaders, excavator auxiliary systems

• Forestry & Mining Equipment — Forestry machinery, underground equipment

• Oil & Gas Service Equipment — Service trucks, winches

• Material Handling Equipment — Forklifts, lift platforms

Expert Maintenance Tips

1. Pre-Installation Preparation

• Back off the main relief valve adjusting screw until spring tension is fully relieved before installing a new pump — this prevents pressure shock damage during start-up

• Verify pump rotation direction matches the drive unit (clockwise / counter-clockwise / bi-rotational — confirm specific configuration)

• Check shaft alignment with the drive shaft; flexible coupling is recommended with concentricity within 0.1 mm

2. Piping & Filtration Requirements

• Install a filter on the inlet line with filtration rating ≥25 μm

• System cleanliness should meet NAS 1638 Class 8 or ISO 4406 17/14 standards

• Inlet pipe diameter must not be smaller than the pump inlet port; piping should be as short as possible with minimal bends to avoid cavitation

• Maintain viscosity within 50 – 7,500 SUS range

3. First Start-Up

• Prime the pump by filling the housing with hydraulic oil before start-up

• Jog the motor to confirm correct rotation direction before running at full speed

• Recommended fluid: ISO VG 46 anti-wear hydraulic oil; use ISO VG 32 for low-temperature environments (<0°C)

• Maintain operating oil temperature between -20°C and +80°C

• Minimum operating speed: 900 RPM

4. Ongoing Maintenance

• Periodically inspect pump housing connections for leaks

• Replace hydraulic oil and filter after the first 500 hours of operation, then every 2,000 hours thereafter

• For rotation direction changes or seal replacement, follow Parker Service Manual HY09-SM030/031/050/051/US

• Note pressure rating difference between PGP075 and PGP076 — PGP075 is optimized for up to 2,500 psi (172 bar) , while PGP076 is rated for higher continuous pressure of 3,000 psi (207 bar) ; verify system operating pressure before selection