Product Overview
The IPH series is a highly representative internal gear pump product line from NACHI, renowned globally for its high pressure, low noise, and long service life. This series includes single pumps and duplex pump configurations such as IPH-34A-15-32-TT-11, IPH-34B-10-25-11, IPH-34B-10-20-11, and IPH-4B-32-20, widely used in high-pressure hydraulic systems, construction machinery, and industrial equipment.
As a professional hydraulic component manufacturer, we provide 100% interchangeable replacement solutions for the NACHI IPH series. Every IPH series internal gear pump undergoes 100% performance testing under simulated actual operating conditions—from displacement accuracy and pressure stability to volumetric efficiency—fully benchmarked against NACHI original equipment standards. The pump body is manufactured from high-strength cast iron, with core gear units featuring modified involute short-tooth gear design, precision-machined and heat-treated to ensure exceptional durability and reliability.
Model Code Explanation:
IPH: Internal gear pump series code
Size Series: 2, 3, 4, 5, 6 (larger numbers indicate larger specifications)
Mounting Type: A = Foot mounting; B = Flange mounting
Displacement: Theoretical displacement in cm³/rev (e.g., 10, 15, 32)
Suffix: 11 = 16 MPa pressure rating; 20 = 25 MPa pressure rating
Special Suffixes: L = Long shaft; T = High-temperature; LT = Low-temperature; E = Special seal configuration
Duplex Pump Models (e.g., IPH-34A-15-32-TT-11): First digit (3) = head pump size, second digit (4) = tail pump size; 15 and 32 = head and tail pump displacements respectively; TT = duplex pump connection type
Technical Specifications
IPH-34A-15-32-TT-11 (Duplex Pump)
Series: IPH-3 (Head Pump) / IPH-4 (Tail Pump) Duplex Combination
Head Pump Displacement: 15 cm³/rev (approx.)
Tail Pump Displacement: 32 cm³/rev (approx.)
Rated Pressure: 25 MPa (255 kgf/cm²)
Peak Pressure: 30 MPa (306 kgf/cm²)
Minimum Speed: 600 min⁻¹
Maximum Speed: 2,000 min⁻¹
Control Type: Internal gear pump, fixed displacement
Mounting Method: Foot mounting (A)
Connection Type: TT (Duplex pump connection)
Fluid Compatibility: Petroleum-based hydraulic fluid
Weight: Approx. 28 kg
IPH-34B-10-25-11 (Duplex Pump)
Series: IPH-3 (Head Pump) / IPH-4 (Tail Pump) Duplex Combination
Head Pump Displacement: 10 cm³/rev (approx.)
Tail Pump Displacement: 25 cm³/rev (approx.)
Rated Pressure: 25 MPa (255 kgf/cm²)
Peak Pressure: 30 MPa (306 kgf/cm²)
Minimum Speed: 600 min⁻¹
Maximum Speed: 2,000 min⁻¹
Control Type: Internal gear pump, fixed displacement
Mounting Method: Flange mounting (B)
Fluid Compatibility: Petroleum-based hydraulic fluid
Weight: Approx. 28 kg (configuration dependent)
IPH-34B-10-20-11 (Duplex Pump)
Series: IPH-3 (Head Pump) / IPH-4 (Tail Pump) Duplex Combination
Head Pump Displacement: 10 cm³/rev (approx.)
Tail Pump Displacement: 20 cm³/rev (approx.)
Rated Pressure: 25 MPa (255 kgf/cm²)
Peak Pressure: 30 MPa (306 kgf/cm²)
Minimum Speed: 600 min⁻¹
Maximum Speed: 2,000 min⁻¹
Control Type: Internal gear pump, fixed displacement
Mounting Method: Flange mounting (B)
Fluid Compatibility: Petroleum-based hydraulic fluid
Weight: Approx. 28 kg (configuration dependent)
IPH-4B-32-20 (Single Pump)
Theoretical Displacement: 32.3 cm³/rev
Rated Pressure: 25 MPa (255 kgf/cm²)
Peak Pressure: 30 MPa (306 kgf/cm²)
Minimum Speed: 500 min⁻¹
Maximum Speed: 2,000 min⁻¹
Control Type: Internal gear pump, fixed displacement
Mounting Method: Flange mounting (B)
Rotation Direction: Clockwise (viewed from shaft end)
Fluid Compatibility: Mineral oil
Weight: Approx. 16.2 kg (Type A) / 10.5 kg (Type B)
Important Note: The above specifications are compiled from NACHI official technical documentation. Duplex pump specifications may vary depending on the combination configuration. Please refer to the product nameplate or technical agreement for exact specifications.
Key Technical Advantages
1. Patented Axial & Radial Pressure Loading Technology for Ultra-High Efficiency and High Pressure
The IPH series features NACHI’s patented axial and radial pressure loading system, delivering up to 30 MPa (306 kgf/cm²) with exceptional efficiency. This proprietary technology ensures stable volumetric efficiency across the entire pressure range, with measured volumetric efficiency ≥ 95%. Compared to conventional gear pumps, the IPH series offers significant efficiency advantages with minimal power loss and reduced fluid temperature rise, effectively lowering system energy consumption.
2. Modified Involute Short-Tooth Internal Gear Design for Ultra-Low Noise and Pulsation
The IPH series utilizes modified involute short-tooth gears for internal meshing, dramatically reducing pressure pulsation and operating noise. Measured operating noise is ≤ 70 dB(A), placing it among the industry’s best. This low-noise characteristic makes it ideal for noise-sensitive environments such as precision machine tools and medical equipment hydraulic systems.
3. Exceptional Durability with Extremely Long Service Life
Thanks to the perfect combination of high-strength cast iron pump body and precision-machined gears, the IPH series delivers outstanding wear resistance and extremely long service life. Internal moving components are manufactured from high-quality materials, maintaining stable performance across the full pressure and speed ranges, significantly reducing total lifecycle maintenance costs.
4. Simple Structure for Extremely Convenient Maintenance
The IPH series features a simple pump body design that facilitates easy maintenance and inspection. Internal components can be inspected and replaced without complex disassembly tools. Additionally, all new design series models maintain mounting interchangeability with previous designs, providing great convenience for equipment upgrades and retrofits.
5. Comprehensive Product Line with Flexible Configuration Options
The IPH series offers complete displacement coverage from 3.6 cm³/rev to 125.9 cm³/rev, encompassing the full IPH-2 through IPH-6 size series. Available in both single pump and duplex pump configurations, with special suffix options including L (long shaft), T (high-temperature), LT (low-temperature), and E (special seal) to accommodate diverse operating conditions.
Application Areas
Injection Molding & Die-Casting Machines: Precise flow and pressure control for molding processes
Construction Machinery: Hydraulic systems for excavators, loaders, and related equipment
Machine Tool Hydraulic Systems: Spindle drives, feed systems, and lubrication systems
Forging Machinery & Press Brakes: Stable high-pressure oil supply
Marine Hydraulic Systems: Steering gears, winches, and other marine hydraulic power supplies
Wind Power Generation: Gearbox lubrication and pitch control systems
Metallurgical Equipment: Rolling mill hydraulic systems, coilers, and more
Test Equipment: High-pressure oil sources for aerospace ground test facilities
Expert Maintenance Tips
1. Fluid Cleanliness Management
Internal gear pumps are highly sensitive to fluid cleanliness. Use hydraulic fluid meeting NAS Class 7 or higher cleanliness standards. Install high-precision filters on the pump suction line. Maintain operating temperature within -20°C to 80°C—for applications outside this range, select T (high-temperature) or LT (low-temperature) suffix special models.
2. First Start-up and Air Bleeding
Purge air from the highest point of the pump body before the first start-up to ensure the pump cavity is fully filled with hydraulic fluid. Never start the pump dry—this will cause severe wear or seizure of gears and bearings.
3. Verify Rotation Direction
The pump must only be operated in the specified rotation direction. Always verify that the rotation direction marked on the nameplate matches the drive motor’s rotation. Reverse operation will prevent proper suction and damage the shaft seal.
4. Coupling Installation and Shaft Alignment
The pump connects to the motor via coupling. Ensure proper coaxial alignment between the pump shaft and motor shaft, with misalignment not exceeding 0.05 mm. Excessive misalignment will cause abnormal bearing loads and shorten pump service life.
5. Pressure Setting Precautions
-11 suffix models: Rated pressure 16 MPa, peak 20 MPa
-20 suffix models: Rated pressure 25 MPa, peak 30 MPa
Never exceed rated pressure during continuous operation. Peak pressure is permitted for short-term transient conditions only.
6. Regular Inspection and Maintenance
Inspect the system filter element condition every 500 operating hours. Regularly monitor the pump for abnormal operating noise—if abnormal noise or system pressure drop is detected, shut down immediately for inspection. Bearing design life exceeds 30,000 hours.
