Parker PGP620 Series Fixed Displacement External Gear Pump

Product Description

The PGP620 belongs to Parker PGP600 heavy-duty cast iron gear pump family. It is a high-pressure, low-noise fixed-displacement external gear pump for mobile and industrial hydraulics. Its matching gear motor is PGM620. Different from the aluminium PGP500 series, PGP620 adopts robust cast iron housing and an interlocking flange-housing structure for high rigidity and quiet operation. Single, tandem, multi-section and common-inlet cross-frame configurations are available. It is widely used in heavy mobile machinery requiring stable high-pressure output and long service life.

1. Overview

PGP620 is an external-meshing fixed displacement gear pump with pressure-balanced thrust plates and precision gear pair. The unique interlocking design reduces operating noise significantly compared with conventional cast iron gear pumps. Its modular construction provides flexible selections of mounting flanges, shaft ends, port layouts, seal materials and integrated valves. Clockwise (CW) and counter-clockwise (CCW) rotation are standard options. It is the preferred heavy-duty cast iron gear pump for tractors, construction equipment, material handling and municipal vehicles.

2. Construction & Key Features

1. High-strength cast iron housing with interlocking flange design: Excellent rigidity, resistance to pressure deformation, low noise emission and strong adaptability to harsh dusty, shock and temperature-variable working conditions.
2. Pressure-balanced thrust plates: Automatically compensates axial clearance, maintains high volumetric efficiency throughout service life and reduces friction and wear.
3. Heavy-duty journal bushing design: Fluid-lubricated bearings for stable continuous operation. Axial thrust on the drive shaft is not permitted. Outboard bearing versions are optional for heavy radial load applications.
4. Precision ground optimized gear set: Low flow ripple, quiet operation, volumetric efficiency up to 97%.
5. Modular design: Multiple SAE flanges, rectangular through-bolt flanges, shaft ends and port styles are optional. Tandem / multi-section pumps with common inlet are supported to feed independent hydraulic circuits from one drive source.
6. Integrated valve options:
   • Relief valve with anti-cavitation check valve
   • Priority flow valve
   • Load-sensing unloading valve
   • Solenoid unloading relief valve, cross-port relief valve, etc.

3. Main Technical Specifications

• Displacement range: 16 ~ 52 cm³/rev (codes: 0160, 0190, 0230, 0260, 0290, 0330, 0360, 0370, 0410, 0440, 0500, 0520)
• Max continuous pressure:
  • 16–33 cm³/rev: 275 bar (3988 psi)
  • 36–37 cm³/rev: 250 bar (3625 psi)
  • 41 cm³/rev: 220 bar (3190 psi)
  • 44–52 cm³/rev: 210 bar (3045 psi)
• Max intermittent pressure: up to 300 bar (4351 psi)
• Speed range: 500 ~ 3500 rpm; max speed drops to 3000 rpm for 50 / 52 cc/rev
• Rotation: CW / CCW
• Standard mounting: SAE flanges, rectangular through-bolt flange; custom flanges available on request
• Shaft options: keyed shaft, SAE splined shaft, tapered shaft
• Port options: SAE split flange, SAE straight thread, BSPP, metric thread; side or rear port layout
• Compatible fluid: Anti-wear mineral hydraulic oil. FPM fluorocarbon seals optional for water-glycol, emulsion and fire-resistant fluids; FPM seals mandatory for phosphate ester fluids.
• Recommended viscosity: 16 ~ 100 cSt
• Suction requirement: Minimum absolute inlet pressure ≥0.8 bar to avoid cavitation
• Approx. weight: 12.0 ~ 13.3 kg (single pump, varies by displacement and configuration)

4. Typical Applications

• Construction machinery: medium excavators, skid steer loaders, aerial work platforms, compact loaders
• Agricultural equipment: large tractors, combine harvesters, forage harvesters
• Material handling: heavy forklifts, tailgate lifting systems, loading equipment
• Forestry machinery, sanitation trucks, municipal vehicles and stationary industrial hydraulic power units

5. Ordering Code Explanation

Example model: PGP620B0330HP3D1NE3E3

• PGP620: Series identifier (PGM620 = matching gear motor)
• A: Single pump; B: Tandem / multi-section pump
• 0330: Displacement code (33 cm³/rev)
• C / E: Rotation (CCW / CW)
• P3: Flange code
• D1: Shaft type code
• N: Seal material code
• E3E3: Port configuration
• Suffix codes: integrated valve, revision version

Note: Verify port layout, shaft diameter, rotation direction and built-in valves before pump replacement.

6. Operation Guidelines

1. Direct drive by flexible coupling is recommended. Avoid excessive radial shaft loads; select outboard bearing version if significant radial force exists.
2. Suction line must be sized adequately. Keep low inlet pressure drop to prevent cavitation damage to thrust plates and gear sets.
3. Recommended filtration: 10 μm hydraulic filter. Regular oil change is required. Although tolerant to contamination, solid particles accelerate thrust plate wear.
4. Built-in relief valve is only for system protection. It is NOT designed for continuous throttling or pressure regulation duty.
5. For tandem pumps, each section has its independent pressure rating. Check displacement and pressure separately for every section during selection.

7. Differentiation from Related Series

• PGP620: Cast iron, interlocking low-noise design, displacement 16–52 cc/rev, heavy-duty mobile hydraulic
• PGP610: Smaller cast iron model in PGP600 family
• PGP640: Larger cast iron model in PGP600 family, bigger displacement and higher pressure
• PGP502 / 503 / 505 / 511 / 517: Aluminium lightweight pumps of PGP500 series
• PGP350 / PGP365: Traditional three-piece cast iron pumps, different internal structure
• PGM620: Gear motor sharing identical housing, cannot be used as a pump.