Gear pump
Tandem Hydraulic Gear Pump 3PD2F+2PDF 4 Bolt Rectangular
Hengyuhang Tandem Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series couples high-capacity Group 3 primary displacement with versatile Group 2 auxiliary delivery in a rigid European 4-bolt rectangular mounting configuration, providing dependable multi-circuit fluid power and peak pressure capability up to 300 bar.
| Applications of Hengyuhang Tandem Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
Designed for multi-function mobile machinery and industrial hydraulic power units, this dual-stage tandem pump powers main working actuators alongside secondary steering, fan drive, or pilot valve circuits from a single engine drive pad. It delivers continuous, high-efficiency fluid power across agricultural harvesters, forestry forwarders, wheel loaders, drilling rigs, material handling stackers, and heavy industrial compaction presses.
| Key Technical Specifications
Product Model: Hengyuhang Tandem Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
Brand Replacement: CASAPPA, Rexroth, Marzocchi, Parker OEM or as requested.
Displacement: Front Stage (Group 3): 20 to 71 cm³/rev; Rear Stage (Group 2): 4 to 30 cm³/rev
Rotation Direction: Clockwise (D), counter-clockwise (S), reversible (R)
Speed Range: Min. speed 500 to 700 r/min; Max. speed 2800 to 3500 r/min
Peak Pressure: Up to 300 bar (4,350 psi)
- Description
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| Overview of HENGYUHANG Tandem Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
The HENGYUHANG 3PD2F+2PDF 4-Bolt Rectangular Series provides an engineered dual-circuit fluid power package that combines a high-volume Group 3 (3PD2F / 3PDF) front pump section with an agile Group 2 (2PDF) rear pump section. Configured with a standard European 4-bolt rectangular mounting flange (centring spigot Ø 50.8 mm / 2.00 inches, rectangular bolt hole pattern 128.0 mm × 98.5 mm), this multi-stage assembly is mechanically driven from a single input shaft through a heavy-duty internal splined through-drive coupling, driving two distinct hydraulic circuits with complete independence in operating pressure and fluid flow.
This series offers direct 1:1 OEM interchangeability across 27 leading European and global hydraulic pump manufacturers, including CASAPPA, Bosch Rexroth, MARZOCCHI, PARKER, and DANFOSS. The front Group 3 pump section spans displacements from 20.0 to 71.0 cm³/rev, handling primary high-power demands such as boom elevation, bucket crowd, hydrostatic auxiliary charge, and high-flow winches at continuous operating pressures up to 250 bar (3,625 psi) and peak pressures up to 300 bar (4,350 psi). The rear Group 2 pump section covers displacements from 4.0 to 30.0 cm³/rev, independently serving priority hydrostatic power steering, thermostatic fan drive loops, pilot joystick controllers, or brake cooling circuits.
Built for heavy industrial duty, the pump incorporates high-tensile extruded aluminum alloy gear casings clamped between high-strength spheroidal ductile cast-iron front mounting flanges, intermediate connection brackets, and rear end-plates. This composite construction achieves exceptional structural rigidity, mitigating barrel dilation and cyclic pressure fatigue under continuous heavy-duty loading. Precision-hobbed, case-hardened alloy steel gear sets run in high-capacity hydrodynamic composite DU/PTFE sleeve bushings. Independently floating hydrostatic thrust balance plates compensate for axial thermal expansion and mechanical wear, sustaining volumetric efficiency above 94% while suppressing pressure pulsations and acoustic emissions throughout extended service cycles.
| Dimension of HENGYUHANG Tandem Hydraulic Gear Pump 3PD2F+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", through-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 or SAE) |
| Intermediate drive coupling | High-strength internal involute splined sleeve coupling transferring driving torque from the Group 3 through-shaft to the Group 2 driven gear journal |
| 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 Group 3 and Group 2 inlets) / Common merged suction port located on intermediate body (optional for consolidated tank line piping) |
| Front stage ports (Group 3) | European 4-bolt diamond flange (standard) / SAE 4-bolt split flange (Code 61) / BSPP threaded ports / Metric straight thread ports |
| Rear stage ports (Group 2) | 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 extruded aerospace-grade aluminum gear housings with heavy-duty ductile cast-iron front mounting flange, intermediate coupling bracket, and rear cover |
| Flange mounting bolt torque | 65 ± 5 Nm (48 ÷ 51 lbf ft) for M10 Grade 8.8 mounting bolts |
| Tie-rod clamp bolt torque | Group 3 section: 80 ± 5 Nm; Group 2 section: 60 ± 4 Nm |
| Pump Installation Specifications HENGYUHANG 3PD2F+2PDF 4-Bolt Rectangular Series
The HENGYUHANG 3PD2F+2PDF European rectangular flange tandem series utilizes an unambiguous modular model numbering system:
Code structure — reference: 3PD2F+2PDF-E4B — Group 3 + Group 2 European 4-Bolt Rectangular Tandem Gear Pump Series
| Segment | Meaning | Standard Options & Features |
|---|---|---|
| Series Code | 3PD2F+2PDF | Modular cross-group tandem gear pump: Group 3 front stage + Group 2 rear stage |
| Front Displacement | 20 to 71 | Group 3 displacement in cm³/rev (20, 23, 26, 30, 34, 38, 44, 52, 60, 71) |
| Rear Displacement | 04 to 30 | Group 2 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 / SF / G / UN | EF: European diamond flange; SF: SAE split flange; G: BSPP thread; UN: SAE O-ring boss |
| 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 3PD2F+2PDF Equivalent | Interchange Verification Notes |
|---|---|---|
| CASAPPA POLARIS PLP30/20 (Euro 4-Bolt Rect.) | HENGYUHANG 3PD2F+2PDF Series | 100% direct drop-in; identical pilot Ø 50.8 mm, 128 × 98.5 mm bolt pattern, 1:8 taper shaft, and stage displacements |
| Bosch Rexroth AZPG + AZPF Tandem (Euro Rect.) | HENGYUHANG 3PD2F+2PDF Series | Seamless mechanical envelope, shaft taper, and pressure performance match for European agricultural machinery |
| MARZOCCHI GHP3 / ALP3 + GHP2 / ALP2 Tandem | HENGYUHANG 3PD2F+2PDF Series | Exact match on European rectangular flange spigot, port drilling centers, and through-drive torque ratings |
| PARKER PGP517 + PGP511 Tandem (Euro 4-Bolt) | HENGYUHANG 3PD2F+2PDF Series | Complete bolt-pattern, shaft taper, and hydraulic flow replacement for mobile construction equipment |
| DANFOSS SNP3 + SNP2 / SNW3 + SNW2 Tandem | HENGYUHANG 3PD2F+2PDF Series | Direct drop-in fit for European combine harvesters, telescopic telehandlers, and forestry forwarders |
| BUCHER Hydraulics AP300 + AP200 Tandem | HENGYUHANG 3PD2F+2PDF Series | Direct drop-in fit for industrial power packs, drilling rigs, and heavy material handling equipment |
| Galtech 3SPA + 2SPA Tandem (Euro 4-Bolt Mount) | HENGYUHANG 3PD2F+2PDF Series | Identical mounting pilot, through-shaft torque distribution, and port centerline dimensions |
| VIVOLO (Vivoil) X3P + X2P / XV-3P + XV-2P Tandem | HENGYUHANG 3PD2F+2PDF Series | Fully interchangeable on European 4-bolt rectangular mounting flange, drive shaft, and hydraulic flow characteristics |
Techspecs — HENGYUHANG Tandem Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
Performance Data Across Displacements
Front Stage — Group 3 (3PD2F / 3PDF)
| 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) |
|---|---|---|---|---|---|---|---|---|
| 3PD2F-20 | 20.0 | 1.22 | 250 / 3,625 | 280 / 4,060 | 300 / 4,350 | 600 | 3,500 | 30.0 |
| 3PD2F-23 | 23.0 | 1.40 | 250 / 3,625 | 280 / 4,060 | 300 / 4,350 | 600 | 3,500 | 34.5 |
| 3PD2F-26 | 26.0 | 1.59 | 250 / 3,625 | 280 / 4,060 | 300 / 4,350 | 500 | 3,200 | 39.0 |
| 3PD2F-30 | 30.0 | 1.83 | 240 / 3,480 | 270 / 3,915 | 290 / 4,205 | 500 | 3,200 | 45.0 |
| 3PD2F-34 | 34.0 | 2.07 | 240 / 3,480 | 270 / 3,915 | 290 / 4,205 | 500 | 3,000 | 51.0 |
| 3PD2F-38 | 38.0 | 2.32 | 230 / 3,335 | 260 / 3,770 | 280 / 4,060 | 500 | 3,000 | 57.0 |
| 3PD2F-44 | 44.0 | 2.68 | 210 / 3,045 | 240 / 3,480 | 260 / 3,770 | 500 | 2,800 | 66.0 |
| 3PD2F-52 | 52.0 | 3.17 | 190 / 2,755 | 220 / 3,190 | 240 / 3,480 | 500 | 2,800 | 78.0 |
| 3PD2F-60 | 60.0 | 3.66 | 180 / 2,610 | 200 / 2,900 | 220 / 3,190 | 500 | 2,800 | 90.0 |
| 3PD2F-71 | 71.0 | 4.33 | 160 / 2,320 | 180 / 2,610 | 200 / 2,900 | 500 | 2,500 | 106.5 |
Rear Stage — Group 2 (2PDF)
| 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 Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
European Standard 4-Bolt Drop-In Interchangeability
Manufactured to exact European Group 3 4-bolt rectangular mounting standards (pilot Ø 50.8 mm, bolt hole spacing 128.0 × 98.5 mm) with standard 1:8 tapered drive shafts, ensuring zero-modification drop-in substitution across 27 major European and international pump brands.
High-Density Multi-Circuit Integration
Combines a high-displacement Group 3 primary stage (up to 71 cm³/rev) with an agile Group 2 secondary stage (up to 30 cm³/rev), supplying main working hydraulics and secondary steering/cooling circuits from a single PTO mounting station.
Heavy-Duty Through-Drive Torque Transmission
Features an internal hardened involute splined through-drive coupling engineered to transmit maximum cumulative drive torque under continuous shock loads and heavy cyclic duty without spline backlash or fatigue.
Sustained 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.
Flexible Suction Porting & Consolidated Plumbing
Available with independent separate suction ports for isolated hydraulic fluid loops or an optional merged common inlet, drastically simplifying reservoir suction line plumbing on crowded machine chassis.
Quiet Operation & Minimized Fluid Pulsation
High-precision hobbed and shaved gear profiles minimize fluid trapping and pressure ripple, dampening acoustic emissions across mobile machine operator cabs and stationary industrial environments.
Reference — HENGYUHANG Tandem Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
Series Architecture Across Group 3PD2F + Group 2PDF Tandem Combinations
The modular 3PD2F+2PDF tandem architecture pairs 10 front Group 3 displacements with 10 rear Group 2 displacements, providing over 100 standardized displacement combinations:
Heavy Primary Work Stage (Group 3PD2F): Displacements 20, 23, 26, 30, 34, 38, 44, 52, 60, and 71 cm³/rev for primary mobile equipment boom, arm, winch, and high-pressure work tool circuits.
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 Hydraulic Gear Pump 3PD2F+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: POLARIS Series PLP10, PLP20, PLP30 tandem gear pumps (PLP30+PLP20 European rectangular mounting).
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 3PD2F+2PDF 4-Bolt Rectangular Tandem Gear Pump Series in strict alignment with European standardized mounting dimensions and international fluid power specifications. Every tandem unit undergoes 100% computerized end-of-line verification, including simultaneous multi-circuit continuous pressure hold, multi-speed volumetric efficiency mapping (>94%), through-drive torque 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, 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 Hydraulic Gear Pump 3PD2F+2PDF 4-Bolt Rectangular Series
Mobile Construction Machinery: Wheel loaders, backhoe loaders, skid-steer loaders, compact excavators, and trenchers requiring high-flow boom/bucket hydraulics paired with independent hydrostatic power steering or pilot controls.
Agricultural & Harvesting Equipment: High-capacity agricultural tractors, combine harvesters, forage harvesters, telescopic telehandlers, and forestry forwarders operating dual work circuits from a single engine drive pad.
Material Handling & Lifting Machinery: Heavy rough-terrain forklifts, container reach stackers, mobile aerial boom lifts, and truck-mounted cranes requiring separate main mast lift and auxiliary boom extension circuits.
Drilling & Mining Machinery: Hydraulic blast hole drill rigs, continuous underground mining machinery, tunnel boring auxiliary units, and crawler drill rigs.
Stationary Industrial Hydraulic Power Units (HPUs): Metal scrap balers, hydraulic compaction presses, plastic injection molding auxiliary clamp/eject systems, and machine tool lubrication and cooling loops.
Municipal & Environmental Equipment: Refuse collection trucks, road sweeping vacuum machines, sewer cleaner jetters, and snow clearing equipment.
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 | 10.50 to 18.20 kg (23.15 to 40.12 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 aerospace-grade aluminum extrusions and ductile cast-iron end castings, 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 Hydraulic Gear Pump Group 3PD2F+2PDF 4-Bolt Rectangular Series (20~71 + 4~30 cm³/rev) is a heavy-duty modular dual-stage external gear pump engineered to supply two high-demand hydraulic circuits or provide combined dual-stage high-low fluid power from a single prime mover. Equipped with an industry-standard European Group 3 4-bolt rectangular mounting flange (98.5 × 128.0 mm bolt pitch, Ø50.8 mm centering pilot), this multi-section pump couples a high-flow Group 3 front pump (3PD2F, 20.0 to 71.0 cm³/rev) with a versatile Group 2 rear pump (2PDF, 4.0 to 30.0 cm³/rev) via a heavy-duty internal spline intermediate through-drive coupling. Offering independent displacement pairings across 11 front sizes and 10 rear sizes (total combined displacement from 24.0 up to 101.0 cm³/rev), the front stage operates at continuous working pressures up to 250 bar (peak up to 280 bar), while the rear stage operates at continuous pressures up to 250 bar (peak up to 300 bar). Built with high-strength extruded aircraft-grade aluminium alloy bodies, case-hardened alloy steel precision gears, and hydrostatic axial pressure-balanced DU composite thrust bushings, this tandem series delivers over 94% volumetric efficiency, exceptional mechanical resistance, and a direct 1:1 drop-in replacement for CASAPPA POLARIS (PLP30+PLP20), Bosch Rexroth (AZPN+AZPF), Marzocchi, Parker, and Danfoss dual gear pumps.
| Applications
The 3PD2F+2PDF 4-bolt rectangular tandem hydraulic gear pump series is engineered for multi-function European and international mobile machinery and stationary industrial power units requiring high continuous pressure and large delivery flows across two independent circuits: agricultural tractors and combine harvesters (front implement lifting and loader operations combined with rear auxiliary 3-point hitch and hydraulic steering), heavy counterbalance forklifts and container handlers (main mast elevation combined with carriage side-shift/clamping), wheel loaders, compact excavators, backhoe loaders, dual-speed high-low hydraulic presses (rapid low-pressure tool approach and high-pressure stamping/forming), refuse compactor trucks, hook loaders, timber logging machinery, and industrial hydraulic power units (HPUs) driving multiple automated actuator circuits from a single electric bell-housing.
| Key Specifications Overview
| Parameter | Specification |
|---|---|
| Series Architecture | Modular Dual-Stage External Hydraulic Gear Pump (Group 3 Front 3PD2F + Group 2 Rear 2PDF) |
| Front Stage Displacement (3PD2F) | 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) | 4.0 ~ 30.0 cm³/rev (10 standard sizes: 4.0, 6.0, 8.5, 11.0, 14.0, 16.5, 19.5, 22.5, 26.0, 30.0 cm³/rev) |
| Total Combined Displacement Range | 24.0 ~ 101.0 cm³/rev (modular independent stage pairing: V1 + V2) |
| Continuous Operating Pressure (P1) | Front (3PD2F): 180 ~ 250 bar (250 bar for 20~26 cc) / Rear (2PDF): 170 ~ 250 bar (250 bar for 4~14 cc) |
| Intermittent Operating Pressure (P2) | Front (3PD2F): 200 ~ 265 bar / Rear (2PDF): 190 ~ 275 bar |
| Max. Peak Pressure (P3) | Front (3PD2F): 220 ~ 280 bar / Rear (2PDF): 210 ~ 300 bar |
| Operating Speed Range | 500 ~ 3000 r/min (up to 3500 r/min for smaller displacement pairings) |
| Volumetric Efficiency | ≥ 94% across rated pressure and operating thermal envelope |
| Hydro-Mechanical Efficiency | ≥ 89% ~ 92% |
| Body & Housing Construction | High-tensile extruded aluminium alloy gear bodies with spheroidal ductile cast-iron front mounting flange, intermediate adapter, and rear cover |
| Mounting Flange Standard | European standard 4-bolt rectangular flange (pilot Ø50.8 mm, 98.5 × 128.0 mm bolt pitch, 4 × Ø11.4 mm through holes, flange face 122 × 152 mm) |
| Drive Shaft Standard | European standard 1:8 taper shaft with woodruff key (key width 4.0 mm, M14×1.5 thread, Ø19.0 mm taper base, 47.0 mm total extension) |
| Intermediate Coupling Mechanism | High-strength hardened alloy steel internal spline through-drive coupling shaft connecting Group 3 and Group 2 gear sets |
| Port Configuration Options | Front stage: European 4-bolt rectangular flanged ports (M10 threads); Rear stage: European 4-bolt diamond flanged ports (M6/M8); BSPP threaded or common inlet optional |
| Rotation Direction | Clockwise (D / Right-Hand) standard; Counter-Clockwise (S / Left-Hand) available upon request |
| Hydraulic Fluid Compatibility | Mineral-oil-based hydraulic fluids (HL / HLP to ISO 6743/4; DIN 51524 Class 1 and 2); optimal viscosity 20 ~ 80 mm²/s (cSt) |
| Operating Temperature Range | -20°C to +85°C (standard NBR seals); -15°C to +110°C (optional Viton FKM seals) |
| Assembly Tightening Torques | Flange mounting bolts: 85 ± 5 Nm; Group 3 body tie-rod clamp bolts: 95 ± 5 Nm; Group 2 body tie-rod clamp bolts: 60 ± 4 Nm |
| Technical Performance Matrix Across Available Stages
| Primary Front Stage: Group 3 (3PD2F) | Secondary Rear Stage: Group 2 (2PDF) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Model Code | Displ. (cm³/rev) | P1 (bar) | P3 (bar) | Flow @ 1500 rpm | Model Code | Displ. (cm³/rev) | P1 (bar) | P3 (bar) | Flow @ 1500 rpm |
| 3PD2F-20 | 20.0 | 250 | 280 | 30.0 L/min | 2PDF-04 | 4.0 | 250 | 300 | 6.0 L/min |
| 3PD2F-22 | 22.0 | 250 | 280 | 33.0 L/min | 2PDF-06 | 6.0 | 250 | 300 | 9.0 L/min |
| 3PD2F-26 | 26.0 | 250 | 280 | 39.0 L/min | 2PDF-08 | 8.5 | 250 | 300 | 12.8 L/min |
| 3PD2F-33 | 33.0 | 230 | 270 | 49.5 L/min | 2PDF-11 | 11.0 | 250 | 300 | 16.5 L/min |
| 3PD2F-39 | 39.0 | 230 | 270 | 58.5 L/min | 2PDF-14 | 14.0 | 250 | 300 | 21.0 L/min |
| 3PD2F-46 | 46.0 | 230 | 270 | 69.0 L/min | 2PDF-16 | 16.5 | 230 | 280 | 24.8 L/min |
| 3PD2F-50 | 50.0 | 220 | 260 | 75.0 L/min | 2PDF-19 | 19.5 | 210 | 260 | 29.3 L/min |
| 3PD2F-52 | 52.0 | 220 | 260 | 78.0 L/min | 2PDF-22 | 22.5 | 200 | 250 | 33.8 L/min |
| 3PD2F-55 | 55.0 | 200 | 250 | 82.5 L/min | 2PDF-26 | 26.0 | 180 | 230 | 39.0 L/min |
| 3PD2F-63 | 63.0 | 200 | 250 | 94.5 L/min | 2PDF-30 | 30.0 | 170 | 210 | 45.0 L/min |
| 3PD2F-71 | 71.0 | 180 | 220 | 106.5 L/min | - | ||||
| European 4-Bolt Mounting Flange & Drive Shaft Details
| Interface Feature | Technical Standard & Dimension |
|---|---|
| Flange Standard | European standard Group 3 4-bolt rectangular mounting flange |
| Centering Pilot | Ø50.8 (-0.025 / -0.080) mm pilot diameter with 5.0 mm pilot depth |
| Bolt Hole Pattern & Pitch | 98.5 × 128.0 mm bolt pitch with 4 × Ø11.4 mm through mounting holes (overall flange face 122.0 × 152.0 mm) |
| Drive Shaft Specification | 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 total extension: 33.0 mm taper + 14.0 mm thread) |
| Front Stage Port Connections | European standard 4-bolt rectangular flanged ports with M10 tapped holes (inlet: 51/56/62 mm pitch, Ø27/33 mm bore; outlet: 51/56 mm pitch, Ø19/27 mm bore) |
| Rear Stage Port Connections | European standard 4-bolt diamond flanged ports with M6/M8 tapped holes, or BSPP cylindrical thread |
| 1:1 Direct-Fit OEM Brand Replacement Coverage
| Manufacturer Brand | Direct-Fit Drop-In Tandem Equivalent Series |
|---|---|
| CASAPPA | POLARIS Dual Series (PLP30 + PLP20 / PL30 + PL20 with European 4-bolt rectangular flange) |
| Bosch Rexroth | AZPN-1X + AZPF-1X Group 3 + Group 2 multiple gear pumps (European 4-bolt rectangular mounting) |
| MARZOCCHI | 3P + 2P / ALP3 + ALP2 / GHP3 + GHP2 European 4-bolt modular tandem gear pumps |
| PARKER Hannifin | PGP517 + PGP511 / PGP620 + PGP511 European standard multiple section external gear pumps |
| DANFOSS / Turolla | SNP3NN + SNP2NN Group 3 + Group 2 dual external gear pumps (European 4-bolt flange) |
| VIVOLO (Vivoil) | XV-3P + XV-2P multiple section external gear pumps (European 4-bolt pattern) |
| SALAMI | 3PB + 2PB / 3PE + 2PE dual gear pumps with European rectangular spigot pilot |
| Technical Performance Matrix Across Available Stages
| Primary Front Stage: Group 3 (3PD2F) | Secondary Rear Stage: Group 2 (2PDF) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Model Code | Displ. (cm³/rev) | P1 (bar) | P3 (bar) | Flow @ 1500 rpm | Model Code | Displ. (cm³/rev) | P1 (bar) | P3 (bar) | Flow @ 1500 rpm |
| 3PD2F20 | 20.0 | 250 | 280 | 30.0 L/min | 2PDF4 | 4.0 | 250 | 300 | 6.0 L/min |
| 3PD2F26 | 26.0 | 250 | 280 | 39.0 L/min | 2PDF6 | 6.0 | 250 | 300 | 9.0 L/min |
| 3PD2F33 | 33.0 | 230 | 270 | 49.5 L/min | 2PDF8 | 8.5 | 250 | 300 | 12.8 L/min |
| 3PD2F39 | 39.0 | 230 | 270 | 58.5 L/min | 2PDF11 | 11.0 | 250 | 300 | 16.5 L/min |
| 3PD2F46 | 46.0 | 230 | 270 | 69.0 L/min | 2PDF14 | 14.0 | 250 | 300 | 21.0 L/min |
| 3PD2F50 | 50.0 | 220 | 260 | 75.0 L/min | 2PDF16 | 16.5 | 230 | 280 | 24.8 L/min |
| 3PD2F55 | 55.0 | 200 | 250 | 82.5 L/min | 2PDF19 | 19.5 | 210 | 260 | 29.3 L/min |
| 3PD2F63 | 63.0 | 200 | 250 | 94.5 L/min | 2PDF22 | 22.5 | 200 | 250 | 33.8 L/min |
| 3PD2F71 | 71.0 | 180 | 220 | 106.5 L/min | 2PDF30 | 30.0 | 170 | 210 | 45.0 L/min |
| Original Manufacturer | Direct-Fit Drop-In Tandem Equivalent Series |
|---|---|
| CASAPPA | POLARIS Dual Series (PLP30 + PLP20 / PL30 + PL20 with SAE B 2-bolt flange) |
| Bosch Rexroth | AZPN-1X + AZPF-1X Group 3 + Group 2 multiple gear pumps (SAE B 2-bolt mounting) |
| MARZOCCHI | 3P + 2P / ALP3 + ALP2 / GHP3 + GHP2 SAE B modular tandem external gear pumps |
| PARKER Hannifin | PGP517 + PGP511 / PGP620 + PGP511 SAE B multiple section external gear pumps |
| DANFOSS / Turolla | SNP3NN + SNP2NN Group 3 + Group 2 dual external gear pumps (SAE B mounting) |
| VIVOLO (Vivoil) | XV-3P + XV-2P multiple section external gear pumps (SAE B flange) |
| SALAMI | 3PB + 2PB / 3PE + 2PE dual gear pumps with SAE B 2-bolt pilot |
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