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Parker PGP511 Series Fixed Displacement External Gear Pump

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On 2026-10-24
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Product Description

The PGP511 belongs to Parker PGP500 aluminium gear pump family. It is a medium-frame, high-performance fixed-displacement external gear pump for mobile hydraulics. Its matching gear motor is PGM511. Compared with PGP505, the PGP511 has larger displacement range and higher flow capacity. It adopts optimized gear profile, pressure-balanced thrust plates and journal bushing structure. Single, tandem and multi-section configurations are available, widely used in medium-duty mobile hydraulic systems requiring compact layout, light weight and stable high-pressure output.

1. Overview

PGP511 is an external-meshing fixed displacement gear pump. The optimized gear profile reduces flow ripple and operating noise. Modular construction provides flexible selections of mounting flanges, shaft ends, port styles, seal materials and integrated valves. Clockwise (CW) and counter-clockwise (CCW) rotation versions are standard. It is a preferred aluminium gear pump for agricultural machinery, forklifts, aerial work platforms and medium-sized construction equipment.

2. Construction & Key Features

  1. Three-piece high-strength aluminium housing: Light weight, excellent heat dissipation and sufficient rigidity, suitable for mobile installations with weight and space constraints.
  2. Pressure-balanced thrust plates: Automatically compensates axial clearance, maintains high volumetric efficiency throughout service life, reduces friction and wear.
  3. Journal bushing design: Lubricated by hydraulic fluid, stable bearing capacity for continuous operation. Axial thrust on the drive shaft is not permitted. Outboard bearing versions are optional for applications with heavy radial shaft loads.
  4. Precision ground optimized gear set: Low flow ripple, quiet operation, volumetric efficiency up to 96%.
  5. Modular design: Multiple choices of SAE A 2-bolt flanges, rectangular through-bolt flanges, shaft ends and port forms. Tandem multi-pump assembly is supported, supplying independent hydraulic circuits from one driving 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: 6 ~ 33 cm³/rev (codes: 0060, 0080, 0100, 0110, 0140, 0160, 0190, 0230, 0270, 0310, 0330)
  • Max continuous pressure:
    • 6–19 cm³/rev: 250 bar (3625 psi)
    • 23 cm³/rev: 225 bar (3263 psi)
    • 27 cm³/rev: 190 bar (2755 psi)
    • 31 cm³/rev: 165 bar (2393 psi)
    • 33 cm³/rev: 155 bar (2248 psi)
  • Max intermittent pressure: up to 275 bar (3988 psi)
  • Speed range: 500 rpm ~ 3500 rpm; maximum speed decreases for larger displacement codes
  • Rotation: CW / CCW
  • Standard mounting: SAE A 2-bolt flange, rectangular through-bolt flange; custom flanges 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 are mandatory for phosphate ester fluids.
  • Recommended viscosity: 16 ~ 100 cSt
  • Suction requirement: Minimum absolute inlet pressure ≥0.8 bar to avoid cavitation
  • Approx. weight: 3.4 ~ 5.2 kg (varies with displacement and configuration)

4. Typical Applications

  • Construction machinery: small and medium excavators, skid steer loaders, aerial work platforms
  • Agricultural equipment: tractors, harvesters, forage machinery
  • Material handling: forklifts, tailgate lifting systems, loading equipment
  • Mobile hydraulic power packs, forestry machinery, sanitation trucks

5. Ordering Code Explanation

Example model: PGP511B0160HP2D1NE2E2

  • PGP511: Series identifier (PGM511 = matching gear motor)
  • A: Single pump; B: Tandem / multi-section pump
  • 0160: Displacement code (16 cm³/rev)
  • C / E: Rotation (CCW / CW)
  • P2: Flange code
  • D1: Shaft type code
  • N: Seal material code
  • E2E2: 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

  • PGP511: Aluminium housing, medium frame, displacement 6–33 cc/rev, higher flow than PGP505
  • PGP502 / PGP503: Small-frame aluminium pumps, smaller displacement
  • PGP505: Small-medium frame, displacement 2–12 cc/rev
  • PGP517: Larger frame in PGP500 aluminium family, bigger displacement
  • PGP350 / PGP365: Cast iron heavy-duty pumps for high-flow rugged mobile working conditions
  • PGM511: Gear motor sharing identical housing, cannot be used as a pump

 

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