Tandem Cast Iron Hydraulic Gear Pump 4PT4F+4PTF SAE B 4-Bolt Series

| Overview of HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt Series

The HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt Series is a heavy-duty dual Group 4 tandem external gear pump engineered for demanding mobile machinery and industrial hydraulic installations requiring two high-flow, high-pressure independent hydraulic circuits. Both front (4PT4F) and rear (4PTF) stages are constructed with high-tensile spheroidal graphite cast iron bodies, providing superior fatigue strength, anti-cavitation resilience, and minimal housing deflection under continuous working pressures up to 275 bar and peak pressures reaching 315 bar (4,568 psi). The front 4PT4F stage features an integrated heavy-duty through-drive shaft with an internal involute splined coupling, transmitting full drive torque to the rear 4PTF pump without parasitic shaft flexure. Equipped with a precision-machined SAE B 4-bolt rectangular mounting flange (Centring pilot Ø 101.6 mm / 4.00" with 89.7 mm × 114.3 mm bolt pattern) and standardized SAE splined or keyed drive shafts, this tandem pump delivers 1:1 OEM drop-in interchangeability across premier global brands including Casappa, Parker Commercial, Permco, and Jihostroj.

| Dimension of HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt Series

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

| Pump Installation Specifications HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt Series

| Comprehensive Ordering Code Breakdown (Hengyuhang 4PTF Tandem Series Structure)

Code structure — reference: 4PT4F+4PTF−D1/D2−R−C−S−P1/P2−M−B

| Reading Your Replacement Code

| Techspecs of HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt Series

| Performance Data Across Displacements

Note: Reference catalogue performance ratings based on ISO VG 46 mineral oil, T = 50 °C, ν = 30 mm²/s.

Dual Group 4 Stages (4PT4F / 4PTF)

Note: Technical values represent nominal catalogue reference ratings applicable to both the front 4PT4F and rear 4PTF pump stages. Combined multi-stage flow can exceed 270 l/min. Maximum continuous operating parameters are governed by cumulative input drive shaft torque ratings and operating temperature.

| Operating Conditions & Fluid Compatibility

Advantages

Heavy-Duty Cast Iron Construction

High-tensile spheroidal graphite cast iron bodies across both stages resist pressure fatigue, mechanical shock, and body dilation under continuous pressures up to 275 bar and peak pressures reaching 315 bar (4,568 psi).

Rigid SAE B 4-Bolt Mounting Flange

Precision-machined 4-bolt rectangular pattern (89.7 × 114.3 mm) provides exceptional structural rigidity, preventing mounting bracket deflection under severe cyclic impulse loads and continuous high-torque operation.

Dual Independent High-Flow Hydraulic Circuits

Combines two heavy-duty Group 4 gear sets into a single compact footprint driven by one prime mover, independently powering primary working hydraulics and secondary steering/cooling systems without cross-circuit interaction.

Robust Internal Splined Through-Drive

High-strength through-shaft and induction-hardened internal splined coupling transmit full downstream drive torque with zero shaft binding or parasitic journal deflection.

Superior Volumetric Efficiency (>94%)

Hydrostatically balanced floating thrust plates automatically compensate for thermal expansion and face wear, sustaining peak volumetric efficiency across thousands of harsh duty hours.

Low Noise & Hydraulic Pulsation

Precision-ground, case-hardened alloy steel gear profiles minimize trapped fluid pressure pulsation, ensuring smooth, quiet, and reliable operation.

Reference

Series Architecture & Displacements

• Series Nomenclature: HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 4PT4F+4PTF SAE B 4-Bolt Series

• Front Stage (Group 4PT4F): Displacements from 8.0 to 92.0 cm³/rev (18 standard displacement steps).

• Rear Stage (Group 4PTF): Displacements from 8.0 to 92.0 cm³/rev (18 standard displacement steps).

• Flange Standard: SAE B 4-Bolt Rectangular Flange (Pilot Ø101.6 mm / 4.00" h8, 89.7 mm × 114.3 mm bolt pattern).

• Drive Shaft: SAE 13T spline (Code 01, Ø21.8 mm), SAE 15T spline (Code 02, Ø25.0 mm), or SAE keyed shafts.

• Intermediate Coupling: Dedicated Group 4 to Group 4 internal involute splined through-drive coupling.

Comprehensive Interchangeability & Replacement Matrix

The HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt series provides 1:1 drop-in replacement compatibility across the following premier global hydraulic pump manufacturers and designated series:

• CASAPPA: KP30, KP35, KP40, FDP30, HDP30, HDP35, FP30, FP40 cast iron series

• PARKER (Commercial Hydraulics): PGP330, PGP350, PGP315, PGP365, PGP620, PGP640, P20 series

• JIHOSTROJ: QHD0, QHD1, QHD2, GHD0, GHD1, GHD2 heavy-duty series

• DAVID BROWN: Heavy-duty cast iron hydraulic pump series

• METARIS: MH series commercial replacement cast iron pumps

• PERMCO (PERMCOP): P76, P75 series cast iron tandem pumps

• KOMATSU: OEM construction equipment tandem gear pump replacements

• CATERPILLAR: Heavy earthmoving machinery hydraulic implement and steering tandem pumps

• KAYABA (KYB): KFP series cast iron gear pumps

Brand Replacement

The HENGYUHANG 4PT4F+4PTF SAE B 4-Bolt series is precision-engineered as a direct 1:1 drop-in replacement for premier heavy-duty cast iron tandem gear pump lines, notably CASAPPA KP/FP/HDP series, PARKER Commercial PGP330/PGP350/PGP365/PGP620 series, and PERMCO P75/P76 series. Every tandem pump undergoes 100% factory dynamic testing across its full speed and pressure curve to guarantee volumetric efficiency, mechanical output, and dual-circuit pressure isolation up to 315 bar. Utilizing standard SAE B 4-bolt rectangular flange dimensions (Ø101.6 mm pilot, 89.7 × 114.3 mm spacing) and standardized SAE drive shafts, Hengyuhang pumps allow equipment manufacturers and service engineers to perform direct drop-in field replacements without piping rework, bracket redesign, or system modifications. Custom displacement pairings, shared or separate suction ports, and specialized shaft extensions are fully supported with rapid turnaround.

Applications

• Heavy Mobile Construction Machinery: Primary boom lift, bucket actuation, and auxiliary steering or cooling fan circuits on wheel loaders, large excavators, motor graders, and articulated dump trucks.

• Mining & Heavy Haulage Equipment: High-pressure hoist and steering hydraulic circuits on underground mining trucks, blast-hole drill rigs, and aggregate crushing plants.

• Agricultural Harvesters & Tractors: Combined hydraulic implement lift and hydrostatic auxiliary motor drive circuits for high-horsepower tractors, combine harvesters, and forestry forwarders.

• Heavy Material Handling & Port Machinery: Reach stackers, heavy container handlers, rough-terrain cranes, and straddle carriers.

• Industrial Heavy Hydraulic Power Units (HPUs): High-pressure metal forming presses, scrap metal balers, continuous casting machines, and oilfield service rigs.

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 (>94%), 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 (Casappa, Parker, Permco, Jihostroj, Komatsu, Caterpillar, 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.