Product Overview
The ALPP2-D-30-D, ALP2A-D-30-70-D-07, ALAP2-D-40+ALPP2-D-16, and ALAP3-D are representative models of the Italian MARZOCCHI ALP/ALAP series aluminum external gear pumps and tandem gear pumps.
Founded in 1961 and headquartered in Bologna, Italy, MARZOCCHI has become one of the world’s largest manufacturers of gear pumps and gear motors through decades of continuous investment and product development. MARZOCCHI products enjoy an excellent reputation for high quality, high reliability, and superior performance in both industrial and mobile hydraulics.
The ALP series is MARZOCCHI’s standard gear pump product line, available in four groups (Group 1, 2, 3, and 4). ALP2A and ALPP2 belong to Group 2, with displacements ranging from 4.5 to 35.2 cc/rev. ALAP2 and ALAP3 are tandem pump platforms—ALAP2 based on Group 2 frame, ALAP3 based on Group 3 frame (displacement 20 – 87 cc/rev)—with two pump stages driven by a common input shaft, enabling simultaneous oil supply to two independent hydraulic circuits.
Engineered as a direct OEM-replacement solution, these models fully comply with MARZOCCHI original design standards and SAE mounting interface specifications, offering 100% direct interchangeability with OEM pumps. Every unit undergoes 100% workload simulation testing prior to shipment, rigorously validating pressure retention, volumetric efficiency, and internal leakage performance to meet or exceed OEM standards.
Model Code Breakdown (Bulleted List) :
ALPP2-D-30-D
ALPP — Series: MARZOCCHI Aluminum Gear Pump (Rear/End Pump)
2 — Group: Group 2 (medium frame)
D — Interface: SAE flange
30 — Displacement code: 21.1 cc/rev
D — Configuration suffix
ALP2A-D-30-70-D-07
ALP2A — Series: MARZOCCHI ALP2A Aluminum Gear Pump
D — Interface: SAE flange
30 — Displacement code: 21.1 cc/rev
70 — Configuration code
D-07 — Suffix configuration code
ALAP2-D-40 + ALPP2-D-16 (Tandem Combination)
ALAP2 — Front pump: Group 2 Tandem front pump (ALPA = tandem primary pump)
D-40 — Displacement 28.2 cc/rev
ALPP2 — Rear pump: Group 2 Tandem rear/end pump
D-16 — Displacement 11.5 cc/rev
ALAP3-D (Tandem Pump Platform)
Technical Specifications
ALPP2-D-30 / ALP2A-D-30 Series General Specifications
Series: MARZOCCHI ALP2 / ALP2A / ALPP2 Aluminum Gear Pump
Displacement: 21.1 cc/rev
Rated Pressure (Continuous): 180 bar
Peak Pressure (Intermittent): 210 bar
Maximum Speed: 3200 rpm
Theoretical Flow (@1500 rpm): 30.1 L/min
Rotation Direction: Clockwise (viewed from shaft end)
Inlet Port: #12 SAE (3/4″)
Outlet Port: #10 SAE (5/8″)
Mounting Flange: SAE A 2-bolt flange
Shaft Type: Keyed shaft 5/8″ bore × 5/32″ key
Housing Material: High-strength aluminum alloy
Weight: Approx. 3.0 – 3.5 kg
ALP2A-D-40 Specific Specifications
ALPP2-D-16 Specific Specifications
ALAP3-D Series General Specifications
Series: MARZOCCHI ALAP3 Tandem Gear Pump (Group 3)
Displacement Range: 20 – 87 cc/rev
Maximum Pressure: Up to 290 bar
Speed Range: Depends on specific displacement configuration
Pump Type: Tandem Pump
Housing Material: High-strength aluminum alloy
Key Technical Advantages
1. Italian MARZOCCHI Technology – Global Leader
Founded in 1961, MARZOCCHI has become one of the world’s largest manufacturers of gear pumps and gear motors. The ALP/ALAP series embodies decades of technological accumulation and continuous innovation, representing the leading level of external gear pump technology. MARZOCCHI gear pumps enjoy an excellent reputation for high quality, high reliability, and superior performance in both industrial and mobile hydraulics.
2. High-Strength Aluminum Housing – Minimal Deformation Under High Pressure
The pump body, flange, and cover are manufactured from special high-strength aluminum alloys. Even under continuous high pressure, intermittent high pressure, or peak pressure, housing deformation is minimized. Gears are made of special steel that is ground and fine-finished for an excellent surface profile.
3. Optimized Gear Profile – Low Pulsation & Low Noise
Optimized gear tooth profile design and proper geometric proportions ensure low pulsation and low noise levels during pump operation. This makes the ALP/ALAP series particularly suitable for industrial and mobile hydraulic applications with stringent noise requirements.
4. Modular Tandem Pump Design – Flexible Configuration (ALAP2 / ALAP3)
ALAP2 and ALAP3 feature modular tandem pump design. MARZOCCHI gear pumps can be assembled with up to four sections on a single shaft. The front pump is marked ALPA/GHPA, intermediate sections ALPI/GHPI, and the rear/end section ALPP/GHPP. This design enables highly flexible system configurations to meet the multi-circuit oil supply requirements of complex hydraulic systems.
5. Comprehensive Displacement Coverage – Flexible Selection
The ALP2/ALP2A/ALPP2 series offers displacements from 4.5 to 35.2 cc/rev. The ALAP3 series covers 20 – 87 cc/rev. Multiple shaft types (keyed/splined), flange types (SAE A/B), and rotation directions (clockwise/counter-clockwise) are available.
6. Dedicated Design for Hatch Cover Hydraulic Systems
ALPP2-D-30-D and ALP2A-D-30-70-D-07 are specifically designed for ship hatch cover hydraulic systems. The products undergo rigorous marine environment adaptability validation, ensuring long-term reliable operation under harsh conditions including salt spray and humidity.
7. 100% Factory Tested & Direct Interchangeability
Every unit undergoes 100% workload simulation testing prior to shipment, covering pressure retention verification, internal leakage detection, and flow validation. Fully compliant with MARZOCCHI original design standards and SAE mounting interface specifications, with flange dimensions, shaft specifications, and mounting interfaces identical to OEM pumps—direct drop-in replacement with zero modifications required.
Application Areas
Marine Equipment: Cargo hatch cover opening and closing hydraulic systems
Construction Machinery: Excavators, loaders, and other mobile machinery hydraulic systems
Industrial Hydraulic Systems: Hydraulic power units (HPU) for various industrial equipment
Agricultural Machinery: Tractors, combine harvesters, and agricultural equipment
Material Handling Equipment: Forklifts, lifting platforms
Expert Maintenance Tips
1. Model Confirmation
ALPP2-D-30-D and ALP2A-D-30-70-D-07 share the same 21.1 cc/rev displacement but feature different configurations. ALAP2-D-40+ALPP2-D-16 is a tandem pump combination with 28.2 cc/rev front pump (ALAP2-D-40) and 11.5 cc/rev rear pump (ALPP2-D-16). Before installation, confirm the correct pump type and displacement configuration based on system circuit requirements.
2. Rotation Direction Confirmation
The standard version features clockwise rotation (viewed from shaft end). Before installation, always verify that the PTO rotation direction of the host machine matches the pump’s rotation direction—incorrect rotation will result in pump failure to prime and may cause severe damage to gears and bearings within a short period.
3. Installation Precautions
Thoroughly clean the SAE A 2-bolt flange and shaft mating surfaces before installation to ensure no debris remains
Ensure correct connection of inlet port #12 SAE (3/4″) and outlet port #10 SAE (5/8″)
Use MARZOCCHI-specified torque values for mounting bolts—avoid over-tightening which may cause distortion of the aluminum housing
For tandem pump installations, pay special attention to axial alignment accuracy to avoid axial over-positioning that may cause bearing overload
4. First Start-Up and Bleeding
Before first start-up, must fill the pump with hydraulic oil through the inlet port—never start dry
After start-up, run at low speed with no load for 2–3 minutes to ensure complete air evacuation from the system
Check for abnormal noise or leakage—aluminum housing pumps are particularly sensitive to cavitation
5. Fluid and Filtration
Use high-quality anti-wear hydraulic oil compliant with DIN 51524 standards
Maintain system oil cleanliness to ISO 4406 18/15 or better
Aluminum gear pumps are sensitive to contamination—install a high-quality filter in the inlet line
Maintain operating temperature within recommended range
6. Periodic Maintenance
Check mounting bolt torque every 1,000 operating hours
Regularly monitor system operating pressure—ALPP2-D-30 / ALP2A-D-30 not to exceed 180 bar rated (210 bar peak)
Regularly inspect shaft seals to prevent leakage
If flow output decreases, noise levels increase abnormally, or system temperature rises excessively, inspect and replace worn components promptly
For hatch cover system pumps, professional inspection is recommended every 2,000 operating hours or annually (depending on operating conditions)
