Tandem Cast Iron Hydraulic Gear Pump 6PT4F+4PTF SAE C 2-Bolt Series

| Overview of HENGYUHANG 6PT4F+4PTF SAE C 2-Bolt Series

The HENGYUHANG 6PT4F+4PTF SAE C 2-Bolt Series is an ultra-heavy-duty cross-frame tandem external gear pump that couples an extra-high-capacity Group 6 cast iron front pump stage (6PT4F) with a heavy-duty Group 4 cast iron rear pump stage (4PTF). Both pump bodies, front mounting cover, intermediate bracket, and rear cover are manufactured from high-tensile spheroidal graphite ductile iron (QT500), delivering superior fatigue strength, minimal bore expansion under cyclic hydraulic shocks, and high thermal stability. The 6PT4F front stage incorporates an induction-hardened, internal involute splined through-shaft coupling that drives the rear 4PTF stage with zero torsional deflection. Featuring a dedicated SAE C 2-bolt oval mounting flange (Centring pilot Ø 127.0 mm / 5.00" h8, 2-bolt diagonal spacing 181.0 mm / 7.125", 2 clearance holes for 5/8" bolts, Cover Code 02/14) and heavy-duty SAE splined or keyed drive shafts, this series offers 1:1 OEM drop-in interchangeability across leading international manufacturers including CASAPPA, Parker, Jihostroj, Permco, and David Brown.

| Dimension of HENGYUHANG 6PT4F+4PTF SAE C 2-Bolt Series

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

| Pump Installation Specifications HENGYUHANG 6PT4F+4PTF SAE C 2-Bolt Series

| Comprehensive Ordering Code Breakdown (Hengyuhang Tandem Cast Iron Structure)

Code structure — reference: 6PTF−D1/D2−R−C−S−P1/P2−M−B

| Reading Your Replacement Code

| Techspecs of HENGYUHANG 6PT4F+4PTF SAE C 2-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.

Front Stage — Group 6PT4F Cast Iron

Rear Stage — Group 4PTF Cast Iron

Note: Technical values represent nominal catalogue reference ratings. Combined multi-stage flow can exceed 300 l/min. Maximum permissible continuous operating parameters are governed by cumulative input drive shaft torque ratings, operating temperature, and circuit filtration.

| Operating Conditions & Fluid Compatibility

Advantages

Severe-Duty Cast Iron Construction

Both the Group 6 front stage and Group 4 rear stage feature spheroidal graphite ductile iron (QT500) housings, delivering exceptional fatigue resistance and structural stiffness under continuous pressures up to 280 bar and peak pressures reaching 350 bar (5,076 psi).

Standardized SAE C 2-Bolt Flange

Incorporates a standard SAE C 2-bolt oval mounting flange (Centring pilot Ø127.0 mm / 5.00" h8, 181.0 mm diagonal bolt spacing), ensuring seamless drop-in fitment onto heavy mobile and stationary equipment.

Massive Dual Independent Flow Capability

Combines a high-displacement Group 6 front section (up to 135 cm³/rev) with a heavy-duty Group 4 rear section (up to 92 cm³/rev), delivering total combined delivery flows exceeding 300 l/min to independently power heavy hydraulic functions without cross-circuit pressure drops.

Heavy-Duty Group 6 Through-Drive Splined Coupling

Equipped with an oversized, induction-hardened internal involute splined through-drive connection engineered to transmit the full downstream drive torque under continuous high-load duty cycles.

High Volumetric Efficiency (>94%)

Micro-finished high-precision gear pairs and hydrostatically balanced floating thrust plates minimize internal leakage and maintain consistent volumetric efficiency across wide speed and pressure ranges.

Acoustic & Vibration Damping

Heavy cast iron construction naturally absorbs mechanical resonance and fluid pulsation, operating significantly quieter than conventional aluminum pumps in heavy equipment operator environments.

Reference

Series Architecture & Displacements

• Series Nomenclature: HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 6PT4F+4PTF SAE C 2-Bolt Series

• Front Stage (Group 6PT4F Cast Iron): Displacements from 20.0 to 135.0 cm³/rev (14 displacement steps).

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

• Flange Standard: SAE C 2-Bolt oval mount (Cover Code 02, Pilot Ø127.0 mm / 5.00", 181.0 mm hole spacing).

• Drive Shaft: SAE 14T spline (Code 07.00), SAE 1-1/4" straight keyed (Code 04), or SAE 13T/15T splined options.

• Intermediate Coupling: Dedicated heavy-duty Group 6 to Group 4 internal splined through-drive coupling.

Targeted Interchangeability & Replacement Matrix

The HENGYUHANG 6PT4F+4PTF SAE C 2-Bolt series provides 1:1 drop-in replacement compatibility across the following designated international hydraulic pump manufacturers and series:

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

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

• JIHOSTROJ: QHD0, QHD1, QHD2, GHD0, GHD1, GHD2 series

• DAVID BROWN: Heavy-duty cast iron tandem external gear pump series

• METARIS: Heavy-duty cast iron commercial interchange gear pump series

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

• KOMATSU: OEM construction machinery main implement / auxiliary hydraulic pump replacement series

• CATERPILLAR: Heavy earthmoving equipment OEM replacement hydraulic gear pump series

• KAYABA (KYB): KFP series heavy-duty hydraulic gear pumps

Brand Replacement

The HENGYUHANG 6PT4F+4PTF SAE C 2-Bolt series is precision-engineered as a direct 1:1 heavy-duty replacement for premier international gear pump lines, notably CASAPPA KP/FP/HDP, PARKER PGP300/600, JIHOSTROJ QHD/GHD, and PERMCO P75/P76. Every pump undergoes 100% factory dynamic testing across its full speed and pressure envelope to verify volumetric efficiency, mechanical output, and multi-circuit pressure isolation. Utilizing standard SAE C centering dimensions (Ø127.0 mm / 5.00") and precision 14-tooth involute splined 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 Earthmoving & Mining Machinery: Main boom, arm, and swing circuits paired with high-flow auxiliary implement or cooling fan circuits on large mining excavators, wheel loaders, and dozers.

• Drilling & Piling Rigs: High-torque rotary head drives, feed cylinders, and auxiliary mast winches on hydraulic rotary drilling rigs, pile drivers, and continuous miners.

• Heavy Material Handling & Port Equipment: Main mast hoisting and auxiliary power steering/braking circuits for container reach stackers, heavy rough-terrain cranes, and straddle carriers.

• Forestry & Scrap Processing Equipment: Timber forwarders, log loaders, scrap metal shredders, heavy hydraulic shearing machines, and high-tonnage balers.

• Heavy Industrial Hydraulic Power Units (HPUs): Central hydraulic power stations, hydraulic forging presses, high-capacity injection molding machines, and municipal refuse compactor stations.

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 global brands (Casappa, Parker, Jihostroj, Permco, David Brown, 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 spheroidal graphite ductile iron castings, precision 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.