Gear pump
Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4 Bolt Rectangular
Hengyuhang Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series pairs a heavy-duty Group 3 cast iron front stage with a Group 2 secondary stage in a European standard 4-bolt rectangular mount, delivering exceptional pressure fatigue strength, high flow, and peak pressure capability up to 320 bar.
| Applications of Hengyuhang Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
Engineered for high-power European mobile construction and agricultural machinery, this heavy-duty cross-frame tandem pump drives high-flow primary hydraulic work circuits alongside independent secondary steering, cooling fan, or pilot control circuits from a single prime mover drive. It provides reliable, continuous fluid power for mid-sized excavators, wheel loaders, heavy tractors, combine harvesters, telescopic handlers, and industrial hydraulic power packs operating under severe pressure shock cycles.
| Key Technical Specifications
Product Model: Hengyuhang Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
Brand Replacement: CASAPPA, Rexroth, Marzocchi, Parker OEM or as requested.
Displacement: Front Stage (Group 3PT2F Cast Iron): 20 to 71 cm³/rev; Rear Stage (Group 2PDF): 4 to 30 cm³/rev
Rotation Direction: Clockwise (D), counter-clockwise (S), reversible (R)
Speed Range: Min. speed 500 to 600 r/min; Max. speed 2800 to 3500 r/min
Peak Pressure: Up to 320 bar (4,640 psi)
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| Overview of HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
The HENGYUHANG 3PT2F+2PDF 4-Bolt Rectangular Series provides an engineered cross-frame dual-circuit fluid power solution constructed to European mounting standards. It couples a heavy-duty spheroidal graphite ductile cast-iron Group 3 front pump stage (3PT2F) with a precision Group 2 rear pump stage (2PDF). Driven synchronously through an internal induction-hardened splined through-drive intermediate coupling, this assembly eliminates auxiliary multi-pad gearboxes or complex flow dividers while delivering two distinct hydraulic circuits with completely independent operating pressures and flows.
Featuring an industry-standard European Group 3 4-bolt rectangular mounting flange (centring pilot Ø 50.8 mm / 2.00 inches h8, bolt hole pattern 128.0 mm × 98.5 mm), the 3PT2F+2PDF series provides direct 1:1 drop-in interchangeability with OEM tandem gear pumps across 27 leading international hydraulic manufacturers, including CASAPPA, Bosch Rexroth, MARZOCCHI, PARKER, and DANFOSS. The cast iron front stage (3PT2F) covers high displacements from 20.0 to 71.0 cm³/rev, handling severe-duty cyclic work circuits such as boom lift, bucket crowd, main travel drive, or heavy hydraulic winch motors at continuous working pressures up to 280 bar (4,060 psi) and peak pressures up to 320 bar (4,640 psi). The rear Group 2 section (2PDF) covers displacements from 4.0 to 30.0 cm³/rev, independently serving auxiliary power steering, thermostatic fan drive loops, pilot joystick controllers, or brake cooling loops at pressures up to 250 bar.
The front pump body and mounting flange are precision-cast from high-tensile spheroidal graphite ductile iron (QT500), delivering superior fatigue strength, structural stiffness, vibration damping, and resistance to cavitation erosion under extreme cyclic pressure shocks. The rear section utilizes high-tensile extruded aluminum alloy construction. Precision case-hardened alloy steel gears ride within heavy-duty composite DU/PTFE hydrodynamic sleeve bushings. Independently floating hydrostatic axial thrust balance plates continuously equalize running clearances across variable thermal and viscosity gradients, maintaining volumetric efficiencies exceeding 94% while suppressing pressure ripple and acoustic emissions throughout rigorous operational lifespans.
| Dimension of HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
Interface data needed with the drawing:
| Item | Value |
|---|---|
| Front mounting flange | European standard Group 3 4-bolt rectangular flange (centring pilot Ø 50.8 mm / 2.00" h8, bolt hole center spacing 128.0 mm × 98.5 mm / 5.04" × 3.88", clearance holes Ø 11.0 mm for M10 hardware) |
| Primary drive shaft | Standard European 1:8 tapered shaft (T3) with M14 × 1.5 threaded end, slotted nut, and 4.0 mm woodruff key / Optional cylindrical keyed shaft Ø 22.22 mm (7/8") / Involute splined shaft (DIN 5482 B28×25) |
| Intermediate drive coupling | Induction-hardened internal involute splined sleeve coupling transferring driving torque from the 3PT2F front through-shaft to the 2PDF rear drive gear journal, rated for full combined drive torque |
| Rotation direction | Clockwise (D) or Counter-clockwise (S), viewed from drive shaft end (Bi-directional reversible rotation available upon special engineering order) |
| Inlet port routing | Independent separate suction ports (standard: individual 3PT2F and 2PDF suction ports) / Common merged suction port located on intermediate body (optional for consolidated tank line piping) |
| Front stage ports (3PT2F Cast Iron) | European 4-bolt diamond flange (standard) / BSPP threaded ports / Metric straight thread ports / SAE 4-bolt split flange (Code 61) |
| Rear stage ports (2PDF) | European 4-bolt diamond flange (standard) / BSPP cylindrical threaded ports / SAE straight thread O-ring boss (UN/UNF) |
| Seal materials | Standard NBR Buna-N elastomeric seals (-20 °C to +85 °C / -4 °F to +185 °F); Optional Viton (FKM) fluorocarbon seals for high-temperature synthetic fluid applications (-15 °C to +110 °C / +5 °F to +230 °F) |
| Body construction | High-tensile spheroidal graphite ductile cast iron front body and European 4-bolt flange; high-tensile extruded aluminum alloy rear body and ductile cast-iron or aluminum rear end-plate |
| Flange mounting bolt torque | 60 ± 5 Nm (44 ÷ 48 lbf ft) for M10 Grade 8.8 mounting bolts |
| Tie-rod clamp bolt torque | Front 3PT2F section: 110 ± 10 Nm; Rear 2PDF section: 60 ± 5 Nm |
| Pump Installation Specifications HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
The HENGYUHANG 3PT2F+2PDF European rectangular flange tandem cast iron series utilizes an unambiguous modular model numbering system:
Code structure — reference: 3PT2F+2PDF-E4B — Cast Iron Front Group 3 + Group 2 European 4-Bolt Rectangular Tandem Gear Pump Series
| Segment | Meaning | Standard Options & Features |
|---|---|---|
| Series Code | 3PT2F+2PDF | Cross-frame tandem gear pump: Group 3PT2F cast iron front stage + Group 2PDF rear stage |
| Front Displacement | 20 to 71 | Group 3PT2F cast iron displacement in cm³/rev (20.0, 22.5, 26.0, 33.0, 38.0, 44.0, 52.0, 60.0, 71.0) |
| Rear Displacement | 04 to 30 | Group 2PDF rear displacement in cm³/rev (4.0, 6.0, 8.5, 11.0, 14.0, 16.5, 19.5, 22.5, 26.0, 30.0) |
| Rotation | D / S / R | D: Clockwise; S: Counter-clockwise; R: Reversible bi-directional |
| Drive Shaft | T3 / C22 / SP | T3: European 1:8 taper shaft with M14 × 1.5 nut; C22: Ø 22.22 mm cylindrical keyed shaft; SP: Involute splined shaft |
| Mounting Flange | E4B | European standard Group 3 4-bolt rectangular flange (pilot Ø 50.8 mm, 128.0 × 98.5 mm bolt pattern) |
| Inlet Routing | S / C | S: Separate dual suction ports (independent circuits); C: Common single merged suction inlet |
| Port Types | EF / G / UN / SF | EF: European diamond flange; G: BSPP thread; UN: SAE O-ring boss; SF: SAE split flange |
| Seals | N / V | N: Buna-N (NBR) standard; V: Viton (FKM) high-temperature / synthetic fluid seals |
| Auxiliary Options | RV / FD / ST | RV: Integrated pressure relief valve; FD: Priority flow divider valve; ST: Customized OEM specification |
| Reading your replacement code
| Your Target Brand & Model | HENGYUHANG 3PT2F+2PDF Equivalent | Interchange Verification Notes |
|---|---|---|
| CASAPPA PLP30 + PLP20 / Polaris Tandem (Euro 4-Bolt) | HENGYUHANG 3PT2F+2PDF Series | 100% direct drop-in; identical pilot Ø 50.8 mm, 128 × 98.5 mm bolt pattern, 1:8 taper shaft, cast iron front body |
| Bosch Rexroth AZPG + AZPF Tandem (Euro) | HENGYUHANG 3PT2F+2PDF Series | Seamless mechanical envelope, shaft taper fit, and enhanced cast iron front pressure endurance |
| MARZOCCHI GHP3 + ALP2 / GHP2 Tandem (Euro 4-Bolt) | HENGYUHANG 3PT2F+2PDF Series | Exact match on European rectangular flange spigot, port drilling centers, and through-drive torque ratings |
| PARKER PGP517 + PGP511 / PGP505 Tandem | HENGYUHANG 3PT2F+2PDF Series | Complete bolt-hole, shaft taper, and high-pressure hydraulic replacement for mobile construction machinery |
| DANFOSS SNP3NN + SNP2NN / SNP1NN Tandem | HENGYUHANG 3PT2F+2PDF Series | Direct drop-in fit for heavy agricultural tractors, combine harvesters, and wheel loaders |
| BUCHER Hydraulics AP300 + AP200 / AP100 Tandem | HENGYUHANG 3PT2F+2PDF Series | Direct drop-in fit for industrial power packs, drilling rigs, and heavy material handling equipment |
| Galtech 3SPA + 2SPA / 1SPA Tandem (Euro Mount) | HENGYUHANG 3PT2F+2PDF Series | Identical mounting pilot, through-shaft torque distribution, and port centerline dimensions |
| VIVOLO (Vivoil) X3P + X2P / XV-3P + XV-2P Tandem | HENGYUHANG 3PT2F+2PDF Series | Fully interchangeable on European 4-bolt rectangular mounting flange, drive shaft, and hydraulic flow characteristics |
| Techspecs of HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
| Performance Data Across Displacements
Front Stage — Group 3PT2F (Cast Iron Heavy-Duty Through-Drive)
| Model Code | Displacement (cm³/rev) | Displacement (in³/rev) | Continuous Pressure p1 (bar / psi) | Intermittent Pressure p2 (bar / psi) | Peak Pressure p3 (bar / psi) | Min. Speed (r/min) | Max. Speed (r/min) | Flow at 1500 r/min (l/min) |
|---|---|---|---|---|---|---|---|---|
| 3PT2F-20 | 20.0 | 1.220 | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3,500 | 30.00 |
| 3PT2F-22 | 22.5 | 1.372 | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3,500 | 33.75 |
| 3PT2F-26 | 26.0 | 1.586 | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3,500 | 39.00 |
| 3PT2F-33 | 33.0 | 2.013 | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3,200 | 49.50 |
| 3PT2F-38 | 38.0 | 2.318 | 270 / 3,915 | 290 / 4,205 | 310 / 4,495 | 500 | 3,000 | 57.00 |
| 3PT2F-44 | 44.0 | 2.684 | 260 / 3,770 | 280 / 4,060 | 300 / 4,350 | 500 | 3,000 | 66.00 |
| 3PT2F-52 | 52.0 | 3.172 | 240 / 3,480 | 260 / 3,770 | 280 / 4,060 | 500 | 2,800 | 78.00 |
| 3PT2F-60 | 60.0 | 3.660 | 220 / 3,190 | 240 / 3,480 | 260 / 3,770 | 500 | 2,800 | 90.00 |
| 3PT2F-71 | 71.0 | 4.331 | 200 / 2,900 | 220 / 3,190 | 240 / 3,480 | 500 | 2,500 | 106.50 |
Rear Stage — Group 2PDF (Standard Group 2)
| Model Code | Displacement (cm³/rev) | Displacement (in³/rev) | Continuous Pressure p1 (bar / psi) | Intermittent Pressure p2 (bar / psi) | Peak Pressure p3 (bar / psi) | Min. Speed (r/min) | Max. Speed (r/min) | Flow at 1500 r/min (l/min) |
|---|---|---|---|---|---|---|---|---|
| 2PDF-04 | 4.0 | 0.244 | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 4,000 | 6.00 |
| 2PDF-06 | 6.0 | 0.366 | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 4,000 | 9.00 |
| 2PDF-08 | 8.5 | 0.518 | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 3,800 | 12.75 |
| 2PDF-11 | 11.0 | 0.671 | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 600 | 3,800 | 16.50 |
| 2PDF-14 | 14.0 | 0.854 | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 600 | 3,500 | 21.00 |
| 2PDF-16 | 16.5 | 1.006 | 230 / 3,335 | 255 / 3,698 | 280 / 4,060 | 600 | 3,500 | 24.75 |
| 2PDF-19 | 19.5 | 1.189 | 210 / 3,045 | 235 / 3,408 | 260 / 3,770 | 500 | 3,200 | 29.25 |
| 2PDF-22 | 22.5 | 1.372 | 200 / 2,900 | 225 / 3,263 | 250 / 3,625 | 500 | 3,000 | 33.75 |
| 2PDF-26 | 26.0 | 1.586 | 180 / 2,610 | 205 / 2,973 | 230 / 3,335 | 500 | 3,000 | 39.00 |
| 2PDF-30 | 30.0 | 1.830 | 170 / 2,465 | 190 / 2,755 | 210 / 3,045 | 500 | 2,800 | 45.00 |
Note: Operating speed of the complete tandem assembly is governed by the lower maximum speed limit of the two selected pump displacements.
| Operating Conditions & Fluid Compatibility
| Operating Parameter | Specification | Recommendation & Limits |
|---|---|---|
| Hydraulic fluid type | Mineral oil-based hydraulic fluids | HL or HLP hydraulic oils to ISO 6743/4; DIN 51524 Part 1 and 2 |
| Operating viscosity range | 12 to 100 mm²/s (cSt) | Optimum performance viscosity range: 20 to 80 mm²/s (cSt) |
| Cold start viscosity limit | Up to 1,000 mm²/s (cSt) | Permissible during low-speed, low-pressure machine warm-up cycles |
| Fluid operating temperature | -20 °C to +85 °C (-4 °F to +185 °F) | Standard NBR Buna-N seals; Viton (FKM) required for +85 °C to +110 °C |
| Inlet suction line pressure | 0.7 to 3.0 bar absolute (10 to 44 psia) | Minimum 0.7 bar abs. at full working speed to prevent inlet cavitation |
| Fluid cleanliness rating | ISO 4406 Class 20/18/15 | Recommended circuit filtration: β25 ≥ 75 on return or suction filtration loop |
| Drive torque transmission | Involute through-drive intermediate shaft | Input shaft maximum torque must satisfy: Ttotal = Tfront + Trear ≤ Tshaft_limit |
Advantages — HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
Cast Iron Fatigue Durability & Extreme Pressure Resistance
The front 3PT2F pump body and mounting flange are precision-cast from high-tensile spheroidal graphite ductile iron, delivering outstanding fatigue resistance, rigid structural containment, and peak operating pressures up to 320 bar (4,640 psi).
European Standard Group 3 4-Bolt Drop-In Interchangeability
Machined to exact European Group 3 4-bolt rectangular mounting dimensions (pilot Ø 50.8 mm, bolt hole spacing 128.0 × 98.5 mm) with standard 1:8 tapered drive shafts, providing zero-modification drop-in substitution across 27 global pump brands.
Cross-Frame High-Flow Multi-Circuit Delivery
Combines a high-displacement Group 3 primary stage (up to 71 cm³/rev) with a precision Group 2 secondary stage (up to 30 cm³/rev) to power heavy main work and auxiliary control circuits from a single prime mover power take-off.
Heavy-Duty Through-Drive Torque Transmission
Features an induction-hardened internal involute splined through-drive coupling rated to transmit full combined continuous drive torque without driveline backlash or premature spline fretting.
Sustained High Volumetric Efficiency (>94%)
Individual hydrostatic floating thrust balance plates on both pump sections continuously balance axial clearances across temperature and pressure fluctuations, minimizing internal slip and ensuring consistent output flow.
Reduced Noise & Pressure Ripple
High-precision hobbed and shaved gear profiles combined with the superior acoustic dampening of the cast iron front body dramatically reduce operational noise across operator cabs and industrial workstations.
Reference — HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
Series Architecture Across Group 3PT2F Cast Iron + Group 2PDF Tandem Combinations
The modular 3PT2F+2PDF tandem architecture pairs 9 front cast iron displacements with 10 rear Group 2 displacements, generating over 90 standardized displacement combinations:
Heavy Cast Iron Primary Stage (Group 3PT2F): Displacements 20.0, 22.5, 26.0, 33.0, 38.0, 44.0, 52.0, 60.0, and 71.0 cm³/rev for high-flow primary work circuits operating up to 320 bar peak pressure.
Secondary Auxiliary Stage (Group 2PDF): Displacements 4.0, 6.0, 8.5, 11.0, 14.0, 16.5, 19.5, 22.5, 26.0, and 30.0 cm³/rev for priority steering valves, pilot control systems, oil cooling fan motors, and auxiliary brake loops.
Comprehensive Interchangeability Matrix Across 27 Brands
The HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series provides full mechanical, mounting, and hydraulic drop-in substitution for the following 27 international hydraulic manufacturers and their designated pump families:
MARZOCCHI: GHP2A, ALP2A, GHP2, ALP2, 1PD, GHP3, ALP3, GHP3A, ALP3A series tandem and modular gear pumps.
DANFOSS Power Solutions: SNP1NN, SNP3NN, SNW3NN series, SNP2, SNW2 series multi-section hydraulic pumps.
HYDAC: PGE102, PGE103 series, PGE104 series multi-circuit external gear pumps.
ARGO-HYTOS: GP2, GP3, GP1 series tandem external gear pump assemblies.
ATOS: PFG series modular tandem external gear pumps.
Brevini Fluid Power (Dana Brevini): OT100, OT200, OT300 series tandem gear pumps.
BUCHER Hydraulics: AP100, AP200, AP212, AP300 series multi-section gear pumps.
BONDIOLI & PAVESI: HPLPA1, HPLPA2, HPLPA3 series modular tandem gear pump units.
Boden: BAP1 series, BHP1, BAP2, BHP2, BHP3, BAP3 series multi-circuit hydraulic gear pumps.
Caproni: 10A, 20A, 30A, 10C, 20C, 30C series multi-section hydraulic pumps.
CASAPPA: KP20, PHP20, Polaris 20, PLP30 series cast iron and aluminum tandem gear pumps.
CONCENTRIC (Haldex): WP300, WP900, WP1500 series multi-stage external gear pumps.
DUPLOMATIC: 1P, GP2, GP3, GP1 series tandem external gear pumps.
Galtech: 1SPA, 2SPA, 3GPG, 3SPA series multi-circuit tandem hydraulic pumps.
GRH Hydraulics: 1PF, 2PF, 3PF series modular tandem external gear pumps.
HANSA-TMP: 1SP, 2SP, 3GPG, 3SPA series tandem gear pump systems.
HESPER: HA11, HA2, HA3 series, CHP1 series multi-stage hydraulic gear pumps.
HONOR Gear Pumps: 1KH series and Group 2/Group 3 tandem gear pump configurations.
HPI (Hydraulique Professionnelle Industrielle): P1BAN1, P1BAN2, P1AAN2, P1BAN3, P1AAN3 series tandem pumps.
HYDRONIT: E series multi-circuit modular gear pumps.
JIHOSTROJ: P23 series, J series, T3 series, Q2 series, UD series multi-section gear pumps.
PARKER Hannifin: PGP505 series, PGP502 series, PGP511, PGP517 series tandem external gear pumps.
Bosch Rexroth: AZPB series, AZPF, AZPG, AZPN series multi-circuit external gear pumps.
RONZIO: 01ZAG series, 01ZBG series, 02ZAG, 02ZCG, 02ZLG series tandem gear pumps.
ROQUET: 1L0 series, PLA series, GZ series, G series, GLA series, PLC series multi-stage gear pumps.
SDH (Shengda Hydraulics): CBD series multi-section external gear pumps.
VIVOLO (Vivoil): X1P series, XV-1P series, X2P, X3P series, XV-2P, XV-3P series tandem external gear pumps.
Brand Replacement
Quanzhou Hengyuhang Power Technology Co., Ltd. manufactures the 3PT2F+2PDF 4-Bolt Rectangular Tandem Cast Iron Gear Pump Series in strict alignment with European standardized mounting dimensions and high-pressure fluid power specifications. Every tandem unit undergoes 100% computerized end-of-line verification, including simultaneous dual-circuit continuous pressure hold, multi-speed volumetric efficiency mapping (>94%), high-torque through-drive spline integrity testing, and port thread gauge verification. Machinery builders, equipment rebuilders, and hydraulic distributors can replace worn, failed, or long-lead OEM tandem pumps from CASAPPA (PLP30 + PLP20), Rexroth, MARZOCCHI, PARKER, and DANFOSS with zero machine modifications, zero bracket reworking, and zero driveline realignment. Custom displacement combinations, specialized shaft profiles, common inlet manifolds, and integrated pressure relief or priority valves are fully supported with agile production schedules.
Applications — HENGYUHANG Tandem Cast Iron Hydraulic Gear Pump 3PT2F+2PDF 4-Bolt Rectangular Series
Mobile Construction Machinery: Mid-sized excavators, wheel loaders, backhoe loaders, trenchers, and compact crawler cranes requiring high-pressure, high-flow boom/bucket hydraulics paired with independent hydrostatic power steering or pilot controls.
Agricultural & Harvesting Equipment: Heavy tractors, combine harvesters, forage harvesters, self-propelled sprayers, and large round balers operating primary implement circuits alongside auxiliary steering and fan drive loops.
Material Handling & Aerial Equipment: Heavy rough-terrain forklifts, container handlers, reach stackers, and large telescopic boom lifts requiring segregated main mast lift and auxiliary steering circuits.
Forestry & Timber Machinery: Log loaders, forwarders, tree harvesters, wood chippers, and high-capacity stump grinders.
Stationary Industrial Hydraulic Power Units (HPUs): High-tonnage hydraulic presses, metal scrap balers, injection molding clamping units, and high-flow central industrial lubrication systems.
Municipal & Refuse Vehicles: Heavy refuse compactor packing rams, vacuum street sweepers, large municipal snow plows, and sewer jetting vehicles.
Package & Shipping
| Packaging | Neutral heavy-duty export carton with form-fitting high-density molded foam cushioning; individual sealed anti-corrosion VCI barrier bags; export standard fumigation-free wooden pallet consolidation for batch orders. |
|---|---|
| Selling Unit | Single item (MOQ: 1 piece for standard displacement configurations; low MOQ for customized OEM combinations). |
| Single Package Size | 42.0 × 26.0 × 24.0 cm (16.54 × 10.24 × 9.45 in) per tandem pump assembly. |
| Single Gross Weight | 14.50 to 22.80 kg (31.97 to 50.27 lbs) depending on displacement pairing and port options. |
| Standard Lead Time | 3–7 business days for stock displacement pairings; 15–20 business days for tailored OEM batch production. |
| Logistics & Express | Air express (DHL, FedEx, UPS, TNT), air freight, ocean freight (FCL / LCL), and multimodal door-to-door DDP logistics with full tracking. |
| Customization Services | Custom nameplate laser engraving, private brand labeling, specialized shaft spline profiles, custom port threads, and factory CAD verification. |
Why Choose Hengyuhang?
Direct Factory Precision Manufacturing & CNC Excellence: Hengyuhang operates an advanced precision manufacturing facility equipped with multi-axis CNC machining centers, high-speed gear hobbing equipment, and CNC gear profile grinding machines. Operating clearances and gear tooth profiles are held to sub-micron tolerances (Ra < 0.2 μm), ensuring flawless gear meshing, structural rigidity, and long service life.
100% Full-Cycle Multi-Parameter Factory Inspection: Every tandem pump unit undergoes rigorous computerized testing prior to packaging. Testing protocols encompass multi-speed volumetric efficiency benchmarking (>94%), continuous rated and peak pressure endurance, internal casing leakage measurement, through-drive intermediate coupling load verification, and digital acoustic spectrum analysis to guarantee zero-defect delivery.
Seamless 1:1 OEM Drop-In Interchangeability: Engineered to precise European Group 3 4-bolt rectangular flange, standard 1:8 tapered shaft, and port centerline dimensions, Hengyuhang pumps provide 100% form, fit, and functional drop-in replacement for over 27 global hydraulic manufacturers without mounting bracket or plumbing alterations.
Flexible Engineering Customization & Rapid Prototyping: Supported by an experienced hydraulic engineering team, Hengyuhang provides tailored solutions including non-standard displacement combinations, common or separate suction port routing, integrated pressure relief or priority flow control valves, and low-MOQ rapid sampling for new machinery development.
Robust Supply Chain, Extensive Inventory & Fast Global Dispatch: With large strategic raw material reserves of ductile cast-iron and aerospace-grade aluminum extrusions, standard displacement assemblies ship within 48 to 72 hours. Comprehensive international logistics channels ensure dependable door-to-door DDP delivery worldwide.
12-Month Comprehensive Warranty & Lifetime Technical Support: All products are backed by an unconditional 12-month factory warranty. Hengyuhang's dedicated fluid power engineers provide rapid 24-hour CAD mounting verification, cross-reference model decoding, and lifetime technical support for distributors and OEMs worldwide.
Tandem Cast Iron Hydraulic Gear Pump Group 3PT2F+2PDF 4-Bolt Rectangular Series (20.0~71.0 + 4.0~30.0 cm³/rev) is a heavy-duty hybrid dual-stage external gear pump engineered to deliver high-flow, high-pressure fluid power on the primary circuit and compact, responsive auxiliary flow on the secondary circuit from a single prime mover. Equipped with an industry-standard European Group 3 4-bolt rectangular mounting flange (pilot Ø50.8 mm with 98.5 × 128.0 mm bolt pitch), this tandem unit combines a high-strength spheroidal graphite ductile cast-iron front pump (3PT2F) and an extruded aerospace-grade aluminum alloy rear pump (2PDF), joined via an internal spline through-drive coupling shaft. The front ductile cast-iron stage provides exceptional structural rigidity, vibration dampening, and fatigue endurance, completely eliminating housing barrel dilation under severe continuous working pressures (p1) up to 280 bar (4,060 psi) and peak pressures (p3) up to 320 bar (4,640 psi). The rear Group 2 aluminum stage delivers auxiliary hydraulic flow with working pressures up to 250 bar (3,625 psi) while significantly reducing total unit weight. Offering 11 front displacements (20.0 to 71.0 cm³/rev) and 10 rear displacements (4.00 to 30.00 cm³/rev), the 3PT2F+2PDF series provides modular combined delivery capacities from 24.00 up to 101.00 cm³/rev (up to 151.5 L/min @ 1500 rpm). Operating with case-hardened alloy steel precision gears and hydrostatic floating axial pressure balance thrust plates, this series maintains volumetric efficiencies above 94% and serves as a direct 1:1 drop-in replacement for CASAPPA KAPPA+POLARIS (KP30+PLP20), Bosch Rexroth (AZPN/AZPG+AZPF), Marzocchi (GHP3+ALP2), and Parker PGP517+PGP511 European 4-bolt tandem gear pumps.
| Applications
The 3PT2F+2PDF hybrid cast-iron/aluminum 4-bolt rectangular tandem hydraulic gear pump series is specifically designed for severe mobile equipment and industrial machinery where the primary circuit requires high displacement and extreme cyclic pressure handling while the auxiliary circuit powers lower-displacement positioning, pilot, or cooling functions:
Heavy Agricultural Tractors & Harvesters: The high-flow front ductile cast-iron stage (3PT2F) powers high-tonnage front loader cylinders, heavy three-point hitches, and high-pressure implement valves, while the secondary Group 2 aluminum stage (2PDF) delivers steady, responsive flow for hydrostatic power steering, priority brake charging, and auxiliary pilot circuits.
Medium & Heavy Wheel Loaders: The rigid front cast-iron stage reliably powers main boom hoist and bucket tilt cylinders under severe breakout digging shocks, with the secondary aluminum stage dedicated to auxiliary steering and fan drive cooling loops.
Rough-Terrain Telehandlers & Reach Stackers: The primary cast-iron stage supplies high delivery flow for main boom telescopic extension and heavy mast lifting with zero housing deflection, while the secondary stage powers carriage side-shift, frame leveling, and attachment rotation.
Industrial High-Low Press Systems: Operates as an energy-efficient dual-stage high-low pump where both sections join to rapidly pre-fill pressing rams, after which the secondary aluminum stage unloads to tank and the front cast-iron stage maintains high holding pressure up to 280 bar without risk of housing fatigue.
Municipal Refuse Trucks & Heavy Compactors: Withstands continuous cyclic packing blade resistance and container lifting loads on the front heavy-duty cast-iron stage, while providing independent fluid power for auxiliary tailgate locks and bin hoists on the rear stage.
Forestry Harvesters & Timber Loaders: Powers high-flow grapple and boom crane functions on the primary stage, while the rear stage reliably operates cabin positioning and pilot control loops in harsh environmental conditions.
| Key Specifications Overview
| Parameter | Specification |
|---|---|
| Series Architecture | Hybrid Severe-Duty Tandem External Gear Pump (Group 3 Cast Iron Front 3PT2F + Group 2 Aluminum Rear 2PDF) |
| Front Stage Displacement (3PT2F) | 20.0 ~ 71.0 cm³/rev (11 standard sizes: 20, 22, 26, 33, 39, 46, 50, 52, 55, 63, 71 cm³/rev) |
| Rear Stage Displacement (2PDF) | 4.00 ~ 30.00 cm³/rev (10 standard sizes: 4.00, 6.00, 8.50, 11.00, 14.00, 16.50, 19.50, 22.50, 26.00, 30.00 cm³/rev) |
| Total Combined Displacement Range | 24.00 ~ 101.00 cm³/rev (modular dual-stage independent combinations: V1 + V2) |
| Front Stage Operating Pressure (p1/p2/p3) | Continuous (p1) 180 ~ 280 bar (2,610 ~ 4,060 psi); Intermittent (p2) 200 ~ 300 bar; Peak (p3) 220 ~ 320 bar |
| Rear Stage Operating Pressure (p1/p2/p3) | Continuous (p1) 170 ~ 250 bar (2,465 ~ 3,625 psi); Intermittent (p2) 190 ~ 275 bar; Peak (p3) 210 ~ 300 bar |
| Rotational Speed Range | Min. speed: 400 ~ 600 min⁻¹; Max. speed: 2500 ~ 3500 min⁻¹ (determined by combined stage ratings) |
| Volumetric Efficiency | ≥ 94% across rated operating pressure and thermal range |
| Hydro-Mechanical Efficiency | ≥ 89% ~ 92% |
| Body & Housing Construction | Front 3PT2F: Spheroidal graphite ductile cast iron (casing, 4-bolt flange, intermediate adapter); Rear 2PDF: High-strength extruded aluminum alloy body with ductile iron/aluminum rear cover |
| Mounting Flange Standard | European standard Group 3 4-bolt rectangular mounting flange (overall face 122.0 × 152.0 mm, pilot Ø50.8 mm with 98.5 × 128.0 mm bolt pitch, 4 × Ø11.4 mm through holes) |
| Drive Shaft Specification | European standard 1:8 taper shaft with woodruff key (key 4.0 × 12.2 mm, M14×1.5 retaining nut tightened to 80 Nm, max drive torque 280 Nm / 2,478 lbf in, Ø19.0 mm taper base, 47.0 mm shaft extension) |
| Intermediate Coupling Mechanism | High-tensile alloy steel internal spline through-drive coupling connecting Group 3 cast-iron front stage to Group 2 rear stage (allowable intermediate torque: up to 140 Nm) |
| Hydraulic Port Connections | Front stage: European 4-bolt flanged ports with M10 threads or BSPP (G 1-1/4, G 1); Rear stage: European 4-bolt diamond flange or BSPP (G 1/2, G 3/4) |
| Rotation Direction | Clockwise (D / Right-Hand) standard; Counter-Clockwise (S / Left-Hand) available upon request (viewed from drive shaft end) |
| Hydraulic Fluid Compatibility | Mineral-oil-based hydraulic fluids (HL / HLP to ISO 6743/4; DIN 51524 Class 1 and 2); optimal viscosity range: 20 ~ 80 mm²/s (cSt) |
| Operating Temperature Range | -20°C to +80°C (standard NBR seals); -15°C to +110°C (optional Viton FKM seals) |
| Assembly Tightening Torques | Flange mounting bolts: 85 ± 5 Nm (752 ÷ 796 lbf in); Front cast-iron tie-rod bolts: 95 ± 5 Nm; Rear aluminum tie-rod bolts: 60 ± 4 Nm |
| Technical Performance Matrix Across Available Stages
| Section & Model Code | Displacement cm³/rev (in³/rev) | Operating Pressure (bar / psi) | Speed Range (min⁻¹) | Flow @ 1500 rpm (L/min) | Stage Material | |||
|---|---|---|---|---|---|---|---|---|
| Continuous (p1) | Intermittent (p2) | Peak (p3) | Min. Speed | Max. Speed | ||||
| Front Primary Stage (Group 3PT2F Ductile Cast Iron Series — High Flow / High Pressure) | ||||||||
| 3PT2F20 | 20.00 (1.220) | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3500 | 30.00 | Ductile Cast Iron |
| 3PT2F22 | 22.00 (1.343) | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3500 | 33.00 | Ductile Cast Iron |
| 3PT2F26 | 26.00 (1.586) | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3000 | 39.00 | Ductile Cast Iron |
| 3PT2F33 | 33.00 (2.014) | 250 / 3,625 | 270 / 3,915 | 290 / 4,205 | 500 | 3000 | 49.50 | Ductile Cast Iron |
| 3PT2F39 | 39.00 (2.380) | 250 / 3,625 | 270 / 3,915 | 290 / 4,205 | 500 | 3000 | 58.50 | Ductile Cast Iron |
| 3PT2F46 | 46.00 (2.807) | 250 / 3,625 | 270 / 3,915 | 290 / 4,205 | 500 | 3000 | 69.00 | Ductile Cast Iron |
| 3PT2F50 | 50.00 (3.051) | 230 / 3,335 | 250 / 3,625 | 270 / 3,915 | 500 | 3000 | 75.00 | Ductile Cast Iron |
| 3PT2F52 | 52.00 (3.173) | 230 / 3,335 | 250 / 3,625 | 270 / 3,915 | 500 | 3000 | 78.00 | Ductile Cast Iron |
| 3PT2F55 | 55.00 (3.356) | 210 / 3,045 | 240 / 3,480 | 260 / 3,770 | 400 | 2800 | 82.50 | Ductile Cast Iron |
| 3PT2F63 | 63.00 (3.844) | 210 / 3,045 | 240 / 3,480 | 260 / 3,770 | 400 | 2800 | 94.50 | Ductile Cast Iron |
| 3PT2F71 | 71.00 (4.333) | 180 / 2,610 | 200 / 2,900 | 220 / 3,190 | 400 | 2500 | 106.50 | Ductile Cast Iron |
| Rear Secondary Stage (Group 2PDF Extruded Aluminum Series — Auxiliary/Secondary Flow) | ||||||||
| 2PDF-4H-04 | 4.00 (0.244) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 4000 | 6.00 | Extruded Aluminum |
| 2PDF-4H-06 | 6.00 (0.366) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 4000 | 9.00 | Extruded Aluminum |
| 2PDF-4H-08 | 8.50 (0.518) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 3800 | 12.75 | Extruded Aluminum |
| 2PDF-4H-11 | 11.00 (0.671) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 600 | 3800 | 16.50 | Extruded Aluminum |
| 2PDF-4H-14 | 14.00 (0.854) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 600 | 3500 | 21.00 | Extruded Aluminum |
| 2PDF-4H-16 | 16.50 (1.006) | 230 / 3,335 | 255 / 3,698 | 280 / 4,060 | 600 | 3500 | 24.75 | Extruded Aluminum |
| 2PDF-4H-19 | 19.50 (1.189) | 210 / 3,045 | 235 / 3,408 | 260 / 3,770 | 500 | 3200 | 29.25 | Extruded Aluminum |
| 2PDF-4H-22 | 22.50 (1.372) | 200 / 2,900 | 225 / 3,263 | 250 / 3,625 | 500 | 3000 | 33.75 | Extruded Aluminum |
| 2PDF-4H-26 | 26.00 (1.586) | 180 / 2,610 | 205 / 2,973 | 230 / 3,335 | 500 | 3000 | 39.00 | Extruded Aluminum |
| 2PDF-4H-30 | 30.00 (1.830) | 170 / 2,465 | 190 / 2,755 | 210 / 3,045 | 500 | 2800 | 45.00 | Extruded Aluminum |
| Mechanical Drive Guidelines & Torque Limitations
| Mechanical Parameter | Engineering Specification & Limit |
|---|---|
| Primary Shaft Max. Drive Torque (T1_max) | 280 Nm (2,478 lbf in) continuous rating for Group 3 1:8 European taper shaft with M14×1.5 nut and 4.0 mm woodruff key |
| Intermediate Coupling Torque Limit (T2_max) | 140 Nm (1,239 lbf in) max torque transfer capacity for hardened internal spline intermediate through-drive shaft coupling Group 3 to Group 2 |
| Cumulative Drive Torque Verification Formula | T_total = (V1 × p1) / (20 × π × η_hm) + (V2 × p2) / (20 × π × η_hm) ≤ 280 Nm |
| Secondary Stage Torque Verification Formula | T_rear = (V2 × p2) / (20 × π × η_hm) ≤ 140 Nm (protects through-drive intermediate spline coupling) |
| Stage Sequencing Architecture | High-displacement ductile cast-iron primary stage at the front (3PT2F) and auxiliary Group 2 aluminum stage at the rear (2PDF) ensures optimal mechanical stress distribution |
| European Group 3 4-Bolt Mounting Flange, Shaft & Port Details
| Interface Feature | Technical Standard & Dimension |
|---|---|
| Mounting Flange | European standard Group 3 4-bolt rectangular mounting flange (overall face 122.0 × 152.0 mm) |
| Centering Pilot | Ø50.8 mm pilot diameter (-0.025 / -0.080 mm tolerance) with 5.0 mm pilot depth |
| Bolt Hole Pitch & Pattern | 98.5 × 128.0 mm bolt pitch with 4 × Ø11.4 mm through mounting holes |
| Primary Drive Shaft | European standard 1:8 taper shaft with woodruff key (key width 4.0 -0.03 mm, key height 12.2 mm, M14×1.5 retaining nut, Ø19.0 mm taper base, 47.0 mm shaft extension from pilot face) |
| Intermediate Coupling Shaft | Heavy-duty alloy steel internal spline through-drive coupling connecting Group 3 cast-iron front section to Group 2 rear section (allowable torque: up to 140 Nm) |
| Front Stage Port Connections (3PT2F) | European standard 4-bolt rectangular flanged ports with M10 threads (Ø27.0 mm / Ø33.0 mm inlet, Ø19.0 mm / Ø27.0 mm outlet) or optional BSPP (G 1-1/4, G 1) |
| Rear Stage Port Connections (2PDF) | European standard 4-bolt diamond flange (M6/M8 threads) or optional BSPP cylindrical thread (G 1/2, G 3/4) |
| 1:1 Direct-Fit OEM Brand Replacement Coverage
| Manufacturer Brand | Direct-Fit Drop-In Tandem Equivalent Series |
|---|---|
| CASAPPA | KAPPA + POLARIS Hybrid Tandem Series (KP30 Cast Iron Front + PLP20 Aluminum Rear with European 4-bolt rectangular flange) |
| Bosch Rexroth | AZPN / AZPG Group 3 Cast Iron Front + AZPF Group 2 Aluminum Rear multiple gear pump assemblies |
| MARZOCCHI | GHP3 / ALP3 Cast Iron Front + ALP2 Group 2 Aluminum Rear European 4-bolt modular tandem pumps |
| PARKER Hannifin | PGP517 / PGP620 Cast Iron Front + PGP511 Aluminum Rear European standard dual external gear pumps |
| DANFOSS / Turolla | SNP3 / Turolla Group 3 Cast Iron Front + SNP2 Group 2 Aluminum Rear multiple gear pumps |
| SALAMI | 3PB Cast Iron Front + 2PE Aluminum Rear dual gear pumps with European rectangular spigot pilot |
| BUCHER Hydraulics | AP300 / QX3 Cast Iron Front + AP212 Aluminum Rear European 4-bolt double gear pump assemblies |
| Technical Performance Matrix Across Available Stages
| Section & Model Code | Displacement cm³/rev (in³/rev) | Operating Pressure (bar / psi) | Speed Range (min⁻¹) | Flow @ 1500 rpm (L/min) | Stage Material | |||
|---|---|---|---|---|---|---|---|---|
| Continuous (p1) | Intermittent (p2) | Peak (p3) | Min. Speed | Max. Speed | ||||
| Front Primary Stage (Group 3PT2F Ductile Cast Iron Series — High Flow / High Pressure) | ||||||||
| 3PT2F20 | 20.00 (1.220) | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3500 | 30.00 | Ductile Cast Iron |
| 3PT2F22 | 22.00 (1.343) | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3500 | 33.00 | Ductile Cast Iron |
| 3PT2F26 | 26.00 (1.586) | 280 / 4,060 | 300 / 4,350 | 320 / 4,640 | 600 | 3000 | 39.00 | Ductile Cast Iron |
| 3PT2F33 | 33.00 (2.014) | 250 / 3,625 | 270 / 3,915 | 290 / 4,205 | 500 | 3000 | 49.50 | Ductile Cast Iron |
| 3PT2F39 | 39.00 (2.380) | 250 / 3,625 | 270 / 3,915 | 290 / 4,205 | 500 | 3000 | 58.50 | Ductile Cast Iron |
| 3PT2F46 | 46.00 (2.807) | 250 / 3,625 | 270 / 3,915 | 290 / 4,205 | 500 | 3000 | 69.00 | Ductile Cast Iron |
| 3PT2F50 | 50.00 (3.051) | 230 / 3,335 | 250 / 3,625 | 270 / 3,915 | 500 | 3000 | 75.00 | Ductile Cast Iron |
| 3PT2F52 | 52.00 (3.173) | 230 / 3,335 | 250 / 3,625 | 270 / 3,915 | 500 | 3000 | 78.00 | Ductile Cast Iron |
| 3PT2F55 | 55.00 (3.356) | 210 / 3,045 | 240 / 3,480 | 260 / 3,770 | 400 | 2800 | 82.50 | Ductile Cast Iron |
| 3PT2F63 | 63.00 (3.844) | 210 / 3,045 | 240 / 3,480 | 260 / 3,770 | 400 | 2800 | 94.50 | Ductile Cast Iron |
| 3PT2F71 | 71.00 (4.333) | 180 / 2,610 | 200 / 2,900 | 220 / 3,190 | 400 | 2500 | 106.50 | Ductile Cast Iron |
| Rear Secondary Stage (Group 2PDF Extruded Aluminum Series — Auxiliary/Secondary Flow) | ||||||||
| 2PDF-4H-04 | 4.00 (0.244) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 4000 | 6.00 | Extruded Aluminum |
| 2PDF-4H-06 | 6.00 (0.366) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 4000 | 9.00 | Extruded Aluminum |
| 2PDF-4H-08 | 8.50 (0.518) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 700 | 3800 | 12.75 | Extruded Aluminum |
| 2PDF-4H-11 | 11.00 (0.671) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 600 | 3800 | 16.50 | Extruded Aluminum |
| 2PDF-4H-14 | 14.00 (0.854) | 250 / 3,625 | 275 / 3,988 | 300 / 4,350 | 600 | 3500 | 21.00 | Extruded Aluminum |
| 2PDF-4H-16 | 16.50 (1.006) | 230 / 3,335 | 255 / 3,698 | 280 / 4,060 | 600 | 3500 | 24.75 | Extruded Aluminum |
| 2PDF-4H-19 | 19.50 (1.189) | 210 / 3,045 | 235 / 3,408 | 260 / 3,770 | 500 | 3200 | 29.25 | Extruded Aluminum |
| 2PDF-4H-22 | 22.50 (1.372) | 200 / 2,900 | 225 / 3,263 | 250 / 3,625 | 500 | 3000 | 33.75 | Extruded Aluminum |
| 2PDF-4H-26 | 26.00 (1.586) | 180 / 2,610 | 205 / 2,973 | 230 / 3,335 | 500 | 3000 | 39.00 | Extruded Aluminum |
| 2PDF-4H-30 | 30.00 (1.830) | 170 / 2,465 | 190 / 2,755 | 210 / 3,045 | 500 | 2800 | 45.00 | Extruded Aluminum |
| Manufacturer Brand | Direct-Fit Drop-In Tandem Equivalent Series |
|---|---|
| CASAPPA | KAPPA + POLARIS Hybrid Tandem Series (KP30 Cast Iron Front + PLP20 Aluminum Rear with European 4-bolt rectangular flange) |
| Bosch Rexroth | AZPN / AZPG Group 3 Cast Iron Front + AZPF Group 2 Aluminum Rear multiple gear pump assemblies |
| MARZOCCHI | GHP3 / ALP3 Cast Iron Front + ALP2 Group 2 Aluminum Rear European 4-bolt modular tandem pumps |
| PARKER Hannifin | PGP517 / PGP620 Cast Iron Front + PGP511 Aluminum Rear European standard dual external gear pumps |
| DANFOSS / Turolla | SNP3 / Turolla Group 3 Cast Iron Front + SNP2 Group 2 Aluminum Rear multiple gear pumps |
| SALAMI | 3PB Cast Iron Front + 2PE Aluminum Rear dual gear pumps with European rectangular spigot pilot |
| BUCHER Hydraulics | AP300 / QX3 Cast Iron Front + AP212 Aluminum Rear European 4-bolt double gear pump assemblies |
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