Product Overview
The HGP-1A-F3R / HGP-2A-F6R / HGP-3A-F25R are external gear pumps from the Taiwan HYDROMAX HGP series. The HGP-1A-F3R features a displacement of 3 cm³/rev; the HGP-2A-F6R delivers 6 cm³/rev; and the HGP-3A-F25R provides 25 cm³/rev.
The HGP series gear pumps feature a high-strength aluminum alloy housing with precision-ground gear pairs, delivering compact structure, light weight, high efficiency, low noise, and reliable operation. Manufactured to PRC Machinery Industry Standard JB/T 7041, the pump body and covers are precision-cast from high-strength aluminum alloy—lightweight yet robust and high-pressure resistant. Internally, DU composite bearings and high-performance seals ensure low starting torque and excellent sealing. The series is available in four frame sizes with multi-pump combination capability, compatible with SAE, DIN, and European standard shafts, flanges, and port configurations.
Every unit is manufactured to original equipment specifications, ensuring 100% drop-in interchangeability with genuine HYDROMAX HGP series pumps without any system modifications. Each pump undergoes rigorous 100% simulated duty-cycle testing to validate pressure-flow-efficiency performance curves.
Brand Disclaimer: This product is a high-quality compatible replacement engineered for full interchangeability with HYDROMAX original equipment. All HYDROMAX brand names and model codes are referenced solely to indicate compatibility and interchangeability. This product is manufactured by an independent producer and is not an original HYDROMAX product.
Technical Specifications
HGP-1A-F3R
Model Code: HGP-1A-F3R
Brand Series: HYDROMAX HGP-1A Series
Product Type: Fixed Displacement External Gear Pump
Displacement: 3 cm³/rev
Working Pressure: 210 bar (3000 psi)
Maximum Pressure: 250 bar (3500 psi)
Rated Speed: 1,800 rpm
Maximum Speed: 4,500 rpm
Minimum Speed: 600 rpm
Rotation Direction: Right-hand (Clockwise / R)
Mounting: Flange type (F)
Inlet Port Size: 3/8″
Outlet Port Size: 3/8″
Housing Material: High-strength aluminum alloy
Seals: NBR / Viton (optional)
Hydraulic Fluid: Mineral oil, synthetic oil
Weight: 1.15 kg
HGP-2A-F6R
Model Code: HGP-2A-F6R
Brand Series: HYDROMAX HGP-2A Series
Product Type: Fixed Displacement External Gear Pump
Displacement: 6 cm³/rev
Working Pressure: 210 bar (3000 psi)
Maximum Pressure: 250 bar (3500 psi)
Rated Speed: 1,800 rpm
Maximum Speed: 3,500 rpm
Minimum Speed: 700 rpm
Rotation Direction: Right-hand (Clockwise / R)
Mounting: Flange type (F)
Housing Material: High-strength aluminum alloy
Seals: NBR / Viton (optional)
Hydraulic Fluid: Mineral oil, synthetic oil
Weight: 1.72 kg
HGP-3A-F25R
Model Code: HGP-3A-F25R
Brand Series: HYDROMAX HGP-3A Series
Product Type: Fixed Displacement External Gear Pump
Displacement: 25 cm³/rev
Working Pressure: 175 bar (2500 psi)
Maximum Pressure: 210 bar (3000 psi)
Rated Speed: 1,800 rpm
Maximum Speed: 3,000 rpm
Minimum Speed: 700 rpm
Rotation Direction: Right-hand (Clockwise / R)
Mounting: Flange type (F)
Inlet Port Size: PT 1″
Outlet Port Size: PT 3/4″
Housing Material: High-strength aluminum alloy
Seals: NBR / Viton (optional)
Hydraulic Fluid: Mineral oil, synthetic oil
Weight: 3.50 kg
Key Technical Advantages
1. Lightweight Aluminum Alloy Construction
The high-strength aluminum alloy housing, with pump body and covers gravity-cast from aluminum alloy, is lightweight yet robust and high-pressure resistant. The HGP-1A-F3R weighs only 1.15 kg—significantly lighter than cast iron equivalents—making it ideal for weight-sensitive mobile equipment and vehicle-mounted systems.
2. Axial & Radial Clearance Compensation – High Efficiency
The axial and radial clearance automatic compensation mechanism enables the pump to maintain high volumetric efficiency and high mechanical efficiency over extended service life. Paired with SP series gears, it delivers low fluctuation, high pressure, and low noise.
3. DU Composite Bearings & High-Performance Seals – Extended Service Life
Internally, DU composite bearings and high-performance sealing elements deliver low starting torque and excellent sealing, ensuring reliable operation even in harsh working conditions. Viton seals are available for high-temperature applications.
4. Broad Speed & Temperature Operating Range
HGP-1A series supports speeds up to 4,500 rpm, HGP-2A series up to 5,000 rpm, and HGP-3A series up to 3,000 rpm. Maintains stable flow characteristics from low-speed precision control to high-speed continuous duty.
5. Multiple International Standards & Multi-Pump Expandability
Available with SAE, DIN, and European standard flanges, shafts, and port configurations. The series supports single, tandem, triple, and multiple pump combinations. HGP-1A/2A/3A frame sizes can be flexibly combined in series to meet complex multi-circuit hydraulic demands.
6. Reversible Rotation – Maximum Installation Flexibility
Available in both clockwise (R) and counterclockwise (L) rotation directions. Adapts to various drive motor/engine rotation requirements for maximum installation flexibility.
7. 100% Simulated Duty-Cycle Testing
Every pump is 100% tested on dedicated hydraulic test benches under simulated real-world operating conditions—validating pressure-flow characteristics and efficiency curves at rated pressure and full speed range—ensuring zero-defect, plug-and-play performance upon installation.
Application Areas
Construction Equipment: Mini-excavators, loader auxiliary hydraulic systems
Agricultural Machinery: Tractor hydraulic systems, implement hitch control
Lifting & Transport Machinery: Forklifts, lift platform hydraulic systems
Mining Machinery: Mining equipment hydraulic systems
Automotive Industry: Vehicle-mounted auxiliary hydraulic systems
Industrial Equipment: Presses, machine tool hydraulic systems
High-Temperature Applications: Viton seal configuration for elevated temperature operation
Expert Maintenance Tips
1. Fluid Cleanliness Control
Maintain system fluid cleanliness to ISO 4406 19/17/14 or better. Install a 10–25 μm absolute filtration filter upstream of the inlet port to prevent particle contamination from damaging precision gear pairs and DU composite bearings.
2. Inlet Line Requirements
Keep suction lines short and straight with adequate diameter—not less than the port size. Recommended suction line flow velocity: ≤1.5 m/s to prevent cavitation from excessive inlet resistance. Inlet pressure must be maintained between 0.8–2.0 bar (absolute) .
3. Coupling Alignment Precision
Ensure pump shaft-to-drive shaft coaxiality deviation ≤0.05 mm and angular deviation ≤0.5° during installation. Flexible couplings are strongly recommended. If the drive involves sprockets or V-belt pulleys, an independent outboard bearing MUST be installed to protect the pump shaft.
4. First-Start Priming Procedure
Before initial startup, prime the pump by bleeding air through the drain port or a loosened outlet fitting. Perform 2–3 jog starts with the outlet open (no load) until oil fills the pump cavity without air bubbles, then connect the load circuit for full operation.
5. Viscosity & Temperature Monitoring
Recommended operating viscosity: 12–100 cSt. During cold starts when viscosity exceeds the recommended range, ensure adequate suction conditions or preheat the fluid. Standard NBR seals operate from -20°C to +80°C; Viton seals are available for high-temperature applications.
6. Rotation Direction Confirmation
The “R” suffix indicates right-hand (clockwise) rotation; “L” indicates left-hand (counterclockwise). Always verify that the drive motor/engine rotation matches the pump before installation.
