Product Overview
The GPA2-6-6-EK1/2, GPA2-10-10-E, GPA1-4-4-EK1/2, and GPA2-16-E-20-R6.3 are representative models of the VICKERS GPA series low-noise internal gear pumps. The GPA series is manufactured using technology introduced by American Vickers Corporation, available in both single pump and double pump configurations.
The GPA series internal gear pumps feature simple construction, smooth operation, low pressure pulsation, low noise, high reliability, and easy maintenance. The series offers single pump displacements from 1.76 to 63.6 mL/r across nine sizes, which can be combined into various double pump configurations. Rated pressures are available in 6.3 MPa and 10 MPa.
Engineered as a direct OEM-replacement solution, these models fully comply with VICKERS original design standards and 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.
Model Code Breakdown (Bulleted List) :
GPA — Series: Low-noise internal gear pump
1 / 2 / 3 — Frame size: GPA1 (small), GPA2 (medium), GPA3 (large)
First number (e.g., 6 / 10 / 4 / 16) — Single pump displacement (mL/r)
Second number (e.g., 6 / 10 / 4) — Second stage displacement for double pump (mL/r)
E — Pressure rating: E = 10 MPa series
EK1 / EK2 — Configuration: With relief valve (external/internal drain)
20 — Mounting flange specification code
R6.3 — Rotation and shaft configuration code (R = Clockwise)
Technical Specifications
GPA Series General Specifications
Series: VICKERS GPA Low-Noise Internal Gear Pump
Single Pump Displacement Range: 1.76 – 63.6 mL/r (nine sizes)
Rated Pressure: 6.3 MPa and 10 MPa options available
Speed Range: 600 – 3000 r/min
Maximum Speed: 2000 – 3000 r/min
Configuration: Single pump / Double pump
Features: Simple construction, smooth operation, low pressure pulsation, low noise, high reliability, easy maintenance
GPA2-6-6-EK1/2 Specifications
Model: GPA2-6-6-EK1/2
Frame Size: GPA2 (medium)
Pump Type: Double internal gear pump
First Stage Displacement: 6.4 mL/r
Second Stage Displacement: 6.4 mL/r
Total Displacement: 12.8 mL/r
Rated Pressure: 10 MPa (100 bar)
Speed Range: 600 – 3000 r/min
Maximum Speed: 3000 r/min
Configuration: With relief valve (EK1 = external drain / EK2 = internal drain)
Recommended Media: Hydraulic oil
Typical Flow (@1500 rpm, 10 MPa): Approx. 15.6 L/min
GPA2-10-10-E Specifications
Model: GPA2-10-10-E
Frame Size: GPA2 (medium)
Pump Type: Double internal gear pump
First Stage Displacement: 10.4 mL/r
Second Stage Displacement: 10.4 mL/r
Total Displacement: 20.8 mL/r
Rated Pressure: 10 MPa (100 bar)
Speed Range: 600 – 3000 r/min
Maximum Speed: 3000 r/min
Configuration: Standard (without relief valve)
Recommended Media: Hydraulic oil
Typical Flow (@1500 rpm, 10 MPa): Approx. 25.0 L/min
GPA1-4-4-EK1/2 Specifications
Model: GPA1-4-4-EK1/2
Frame Size: GPA1 (small)
Pump Type: Double internal gear pump
First Stage Displacement: 4.0 mL/r
Second Stage Displacement: 4.0 mL/r
Total Displacement: 8.0 mL/r
Rated Pressure: 10 MPa (100 bar)
Speed Range: 600 – 3000 r/min
Maximum Speed: 3000 r/min
Configuration: With relief valve (EK1 = external drain / EK2 = internal drain)
Recommended Media: Hydraulic oil
Typical Flow (@1500 rpm, 10 MPa): Approx. 9.3 L/min
GPA2-16-E-20-R6.3 Specifications
Model: GPA2-16-E-20-R6.3
Frame Size: GPA2 (medium)
Pump Type: Single internal gear pump
Displacement: 17.3 mL/r
Rated Pressure: 10 MPa (100 bar)
Maximum Speed: 3000 r/min
Rotation Direction: Clockwise (R)
Mounting: 4-hole square mounting flange
Filtration: 25 μm
Operating Temperature Range: 0 – 68℃
Recommended Media: Hydraulic oil, EH oil (high-pressure fire-resistant fluid)
Key Technical Advantages
1. Vickers Technology – Low-Noise Internal Gear Design
The GPA series is manufactured using technology introduced by American VICKERS Corporation. The internal gear pump design delivers smooth operation, low pressure pulsation, and low noise—significantly reducing fluid noise and mechanical vibration compared to conventional external gear pumps.
2. Comprehensive Displacement Coverage & Flexible Combinations
Single pump displacements range from 1.76 to 63.6 mL/r across nine sizes. Different displacements can be combined into various double pump configurations. Three frame sizes—GPA1 (small), GPA2 (medium), and GPA3 (large)—meet diverse application requirements from precision machine tools to heavy-duty equipment.
3. Double Pump Design – One Pump, Two Circuits
GPA2-6-6-EK1/2, GPA2-10-10-E, and GPA1-4-4-EK1/2 feature double pump configurations. Two pump stages driven by a common input shaft can supply two independent hydraulic circuits simultaneously, significantly reducing the number of pumps required and saving installation space.
4. Integrated Relief Valve – High System Integration
EK1/EK2 configurations include built-in adjustable relief valves (EK1 = external drain, EK2 = internal drain). System pressure protection is achieved without additional valve blocks, simplifying hydraulic system design and reducing costs.
5. Wide Speed Range – Strong Adaptability
Speed range of 600 – 3000 r/min accommodates various prime mover conditions from low-speed motors to high-speed drives.
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 VICKERS 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
The GPA series internal gear pumps are widely used in the hydraulic systems of the following equipment:
Machine Tools: Various metal cutting machine tools, grinding machines
Injection Molding Machines: Plastic injection molding machine hydraulic systems
Die Casting Machines: Die casting equipment hydraulic systems
Lifting Equipment: Cranes, lift platforms
Baling Machinery: Waste baling machine hydraulic systems
Wood-Based Panel Processing Equipment: Panel production line hydraulic systems
Food Processing Machinery: Food processing equipment hydraulic systems
Turbine EH Control Systems: GPA2-16-E-20-R6.3 is specifically used in turbine EH oil (high-pressure fire-resistant fluid) systems
Expert Maintenance Tips
1. Model Confirmation
The GPA series includes both single and double pump types. GPA2-6-6-EK1/2, GPA2-10-10-E, and GPA1-4-4-EK1/2 are double pump configurations; GPA2-16-E-20-R6.3 is a single pump. Before installation, confirm the correct pump type based on system circuit requirements and verify the complete model code on the pump nameplate.
2. Rotation Direction Confirmation
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 internal components within a short period.
3. Relief Valve Configuration
EK1/EK2 configurations include built-in relief valves. Before installation, verify that the relief valve set pressure meets system requirements and adjust on-site if necessary. EK1 features external drain (drain line connected to tank), while EK2 features internal drain.
4. Installation Precautions
Thoroughly clean the mounting flange (4-hole square flange) and shaft mating surfaces before installation to ensure no debris remains
Use VICKERS-specified torque values for mounting bolts—avoid over-tightening which may cause housing distortion
Ensure correct connection of inlet and outlet ports
Direct drive with flexible coupling is recommended—avoid subjecting the pump to axial or radial loads
5. First Start-Up and Bleeding
Before first start-up, must 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—internal gear pumps are particularly sensitive to cavitation
6. Fluid and Filtration
Use high-quality anti-wear hydraulic oil compliant with DIN 51524 standards
GPA2-16-E-20-R6.3 can be used with EH oil (high-pressure fire-resistant fluid) systems
Recommended filtration: 25 μm
Operating temperature range: 0 – 68℃ (anti-wear hydraulic oil) / 0 – 60℃ (water-glycol)
Maintain system oil cleanliness to ISO 4406 18/15 or better
7. Periodic Maintenance
Check mounting bolt torque every 1,000 operating hours
Regularly monitor system operating pressure—not to exceed 10 MPa (100 bar)
Regularly inspect shaft seals to prevent leakage
If flow output decreases, noise levels increase abnormally, or system temperature rises excessively, inspect and replace worn components promptly
