Multi-stage pump Internal Hydraulic Gear Pump 2APHF SAE A 2-Bolt Oval Flange Series

| Overview of HENGYUHANG 2APHF Multi-Stage Series

The HENGYUHANG 2APHF Multi-Stage Series represents advanced engineering in high-pressure, low-noise internal gear hydraulic pumps. Utilizing a precision internal gear conjugate profile, a crescent seal partition, and active dual gap compensation (both axial thrust plate compensation and radial seal segment compensation), the 2APHF pump counteracts internal deflections under fluctuating system pressures and operating temperatures. This maintains internal clearances and enables volumetric efficiencies up to 93% while keeping acoustic noise levels between 53 and 61 dB(A).

The multi-stage through-drive configuration allows two or more 2APHF pumping elements to be coupled in tandem on a single drive axis, powering independent high-pressure circuits (such as clamp, injection, and auxiliary core-pulling functions in molding machines) with common or separate suction ports. Built with a universal SAE A 2-bolt oval mounting flange (pilot Ø 82.55 mm / 3.25" with 106.4 mm / 4.189" bolt centers) and standardized cylindrical keyed or SAE involute splined drive shafts, the 2APHF multi-stage series serves as a 1:1 OEM drop-in replacement for ECKERLE EIPS1 / EIPS2, HOERBIGER HQI2 / HQI3, and HYDAC PGI100 / PGI101 / PGI102 series without requiring piping redesign or mounting bracket modification.

| Dimension of HENGYUHANG 2APHF Multi-Stage Series

| Interface Data Needed with the Drawing (Dimensional Reference Table)

| Pump Installation Specifications HENGYUHANG 2APHF Multi-Stage Series

| Comprehensive Ordering Code Breakdown (Hengyuhang 2APHF Multi-Stage Structure)

Code structure — reference: 2APHF−D1/D2−R−K−A2−F1−N−M

| Reading Your Replacement Code

| Techspecs of HENGYUHANG 2APHF Multi-Stage Series

| Technical Performance Across Displacements (Per Stage 2APHF Architecture)

Note: Test conditions: mineral oil ISO VG 46, T = 50 °C, ν = 30 mm²/s, n = 1,450 r/min.

Note: Noise measurement condition: Sound pressure level measured in an anechoic chamber at 1.0 m distance per DIN 45635 part 26.

| Operating Conditions & Fluid Compatibility

Advantages

Whisper-Quiet Operation (53 to 61 dB)

Conjugate internal gear meshing and crescent partition eliminate trapped fluid compression, significantly reducing airborne and structure-borne noise compared to external gear units.

Dual Gap Compensation Technology

Integrated axial compensation plates and radial seal segments actively counteract pressure-induced micro-deflections, maintaining volumetric efficiency above 92% across variable speeds and thermal cycles.

Multi-Stage Multi-Circuit Capability

Compact modular through-drive design allows multiple pump stages to be driven from a single electric motor or servo axis, supplying independent high-pressure and low-pressure hydraulic circuits without cross-talk.

Low Pressure Pulsation

Smooth internal tooth engagement minimizes flow ripple to less than 2%, preventing hydraulic shock in servo valves, proportional valves, and precision actuator circuits.

Direct 1:1 OEM Drop-In Replacement

Standard SAE A 2-bolt oval flange (Ø82.55 mm pilot, 106.4 mm bolt spacing) and standardized port interfaces match Eckerle, Hoerbiger, and Hydac dimensions for direct replacement.

Wide Speed Range Compatibility

Stable suction and pressure performance from low speeds (200 r/min) up to 3000 r/min, making it well suited for modern variable-speed servo-electric drive systems.

Reference

Multi-Stage Architecture & Displacements

• Series Designation: HENGYUHANG Multi-Stage Internal Hydraulic Gear Pump 2APHF SAE A 2-Bolt Oval Flange Series

• Modular Stage Platform: Group 2 internal gear platform with 11 standardized displacement sizes (4.2, 5.4, 6.4, 7.9, 10.9, 13.3, 15.8, 19.3, 20.1, 22.2, 25.2 cm³/rev per stage).

• Multi-Stage Combinations: Dual tandem (2APHF+2APHF) or triple pump configurations with independent or shared suction ports.

• Mounting Standard: SAE A 2-Bolt Oval Flange (Pilot Ø82.55 mm / 3.250" h8, 106.4 mm / 4.189" bolt centers).

• Drive Shaft: Cylindrical keyed shaft Ø20 mm (Code K), SAE 16/32-13T spline (Code S1), or SAE 16/32-10T spline (Code S2).

Comprehensive Interchangeability & Replacement Matrix

The HENGYUHANG 2APHF Multi-Stage Series provides 1:1 drop-in replacement compatibility across the following designated international internal gear pump brands and series:

• ECKERLE: EIPS1, EIPS2 series internal gear pumps (and EIPS3 series combinations)

• HOERBIGER: HQI2, HQI3 series high-pressure internal gear pumps

• HYDAC: PGI100, PGI101, PGI102 series low-noise internal gear pumps

Brand Replacement

The HENGYUHANG 2APHF Multi-Stage Series is precision-engineered as a direct 1:1 drop-in replacement for premier European internal hydraulic gear pumps, including the ECKERLE EIPS1/EIPS2 series, HOERBIGER HQI2/HQI3 series, and HYDAC PGI100/PGI101/PGI102 series. Every multi-stage unit undergoes 100% computerized factory testing to verify volumetric efficiency (>92%), mechanical efficiency, multi-circuit pressure hold up to 320 bar, and acoustic emission levels across variable speed profiles. Utilizing standard SAE A 2-bolt oval flange dimensions (pilot Ø82.55 mm, 106.4 mm center distance), standard shaft extensions, and matching flanged port geometries, Hengyuhang pumps allow equipment manufacturers and maintenance teams to perform direct field replacements without piping modification, bell-housing re-machining, or servo drive recalibration. Custom stage displacement pairings and shared or independent suction port configurations are fully supported.

Applications

• Plastic Injection Molding Machines: Servo-driven multi-circuit hydraulic power packs supplying independent clamping, injection, and core-pulling functions.

• CNC Hydraulic Press Brakes & Bending Machines: Precision ram synchronization and pressure-holding circuits requiring low pulsation and quiet operation.

• Die-Casting & Metal-Forming Machinery: Auxiliary accumulator charging, cooling, and high-response proportional hydraulic circuits.

• Industrial Automation & Robotics: Compact hydraulic power units for automated transfer lines, clamping fixtures, and test benches.

• Testing & Laboratory Equipment: Low-noise test rigs requiring smooth flow and minimal pressure ripple.

Package & Shipping

Why Choose Hengyuhang?

• Direct Factory Precision Manufacturing & CNC Excellence: Manufactured in our state-of-the-art production facility equipped with high-precision 4-axis and 5-axis CNC machining centers, automated gear hobbing, and CNC gear tooth profile grinding (Ra < 0.2 μm) to ensure superior surface finish, ultra-tight internal clearances, and maximum volumetric efficiency.

• 100% Full-Cycle Multi-Parameter Factory Inspection: Every single pump undergoes computerized testing before packaging, verifying flow rate at rated speed, volumetric efficiency (>92%), mechanical efficiency, continuous and peak pressure hold, internal bypass, and noise spectrum. Zero untested units leave the factory.

• Seamless 1:1 OEM Drop-In Interchangeability: Dimensionally matched to European, SAE, and DIN standards, providing 1:1 direct mechanical interchangeability across premier global brands (Eckerle, Hoerbiger, Hydac, etc.) with zero mounting modifications required.

• Flexible Engineering Customization & Rapid Prototyping: Supported by a senior fluid power engineering team, offering custom displacement combinations, specialized shaft tapers, splines, integrated priority or relief valves, and non-standard port orientations with rapid sample prototyping and low MOQ requirements.

• Robust Supply Chain, Extensive Inventory & Fast Global Dispatch: Extensive raw material stock of high-grade ductile cast iron castings, alloy steel gear sets, and bearing assemblies enables rapid assembly and 48–72 hour dispatch for emergency breakdown replacements, supported by complete export logistics.

• 12-Month Comprehensive Warranty & Lifetime Technical Support: All pumps are backed by a comprehensive 12-month manufacturer warranty against defects in materials and workmanship, supplemented by 24/7 engineering consultation, CAD drawing verification, and lifecycle technical assistance.