Marzocchi hydraulic pump ALP3A-S-50-FG detailed parameters

1. Model Nomenclature Explanation

• ALP: Product series, indicating the standard pressure external gear pump, which is suitable for medium and low pressure industrial hydraulic systems and adopts an aluminum alloy pump body[6].
• 3A: Size group, representing the specific size classification of the pump (belonging to the ALP3 group), which determines the basic installation dimensions and maximum displacement of the pump, with a displacement range of 20~87 cm³/rev.
• S: Mounting method, standing for shaft extension mounting (different from flange mounting marked with “D”).
• 50: Displacement code, corresponding to the theoretical displacement of the pump (specific value refers to the technical specifications below), which is within the displacement range of the ALP3 group[6].
• FG: Special options, where “F” means equipped with a pressure limiting valve, and “G” means adopting mechanical seal for better sealing performance, which is a common special configuration for Marzocchi ALP series pumps[3].

2. Basic Information

3. Key Technical Specifications

4. Material & Sealing

• Pump Body & Covers: High-strength aluminum alloy, which ensures light weight and good corrosion resistance, suitable for medium and low pressure working conditions, consistent with the material standard of Marzocchi ALP series pumps[3][6].
• Gears: Special hardened steel, precision machined to minimize internal clearance, reduce internal leakage and improve transmission efficiency, which is the standard gear material for ALP series high-performance models.
• Sealing: Mechanical seal (marked with “G” in the model), with NBR sealing material as auxiliary, ensuring good sealing performance and preventing oil leakage; the sealing configuration is consistent with the standard “FG” option of Marzocchi gear pumps[3].

5. Shaft & Mounting Details

• Shaft Type: Conical shaft with a taper of 1:8, equipped with a 6 mm key for stable power transmission (larger key size than ALP2 series to adapt to higher torque).
• Shaft Dimensions: Shaft diameter is 22 mm, shaft length (including fitting edge) is 50 mm, fitting edge diameter is 50 mm; shaft thread size is M16×1.5 (larger dimensions than ALP2 series to match the 3A size group).
• Mounting Type: Shaft extension mounting (code “S”); flange type is European standard 4-hole mounting, centering diameter is 50 mm, which is consistent with the mounting standard of ALP3 group pumps.
• Shaft Load & Torque: Maximum torque is 480 Nm, recommended shaft tightening torque is 85±5 Nm (higher than ALP2 series due to larger displacement and pressure).

6. Port Specifications

• Inlet Port: 1″ BSP (GAS) thread, used for connecting the oil suction pipeline; larger than ALP2 series to meet the higher flow demand of the 50 displacement model.
• Outlet Port: 3/4″ BSP (GAS) thread, used for connecting the oil discharge pipeline to supply hydraulic oil to the system; matched with the inlet port to ensure stable oil flow.

7. Operating Conditions

• Hydraulic Oil Viscosity: Allowed range is 6-500 cst, recommended range is 15-100 cst for optimal performance; the recommended range is slightly adjusted to adapt to larger displacement and higher pressure operation.
• Operating Temperature: -10°C to +80°C (pump start-up and continuous operation temperature range), consistent with ALP series overall operating temperature standard.
• Rotation Direction: Counterclockwise (CCW) under standard configuration; clockwise (CW) can be customized according to user needs, which is the standard rotation direction option for Marzocchi gear pumps.

8. Product Features

• High Efficiency & Stability: Precision-machined gears with minimal clearance reduce internal leakage, ensuring high output efficiency and stable pressure supply; optimized for the ALP3 group’s pressure and displacement characteristics.
• Strong Self-priming Capacity: It can quickly suck hydraulic oil even under low-pressure conditions, adapting to various working environments; the self-priming performance is optimized to match the larger flow demand, and the allowable suction vacuum is 110mm column.
• Low Noise: Optimized gear meshing design and compact structure effectively reduce operating noise, suitable for noise-sensitive occasions; consistent with the low-noise design concept of ALP series.
• High Reliability: Equipped with a pressure limiting valve (marked with “F” in the model) for overload protection, which can automatically adjust or cut off the oil circuit in abnormal conditions to protect the pump and hydraulic system; the pressure limiting valve is matched with the ALP3 group’s pressure parameters.
• Easy Installation & Maintenance: Compact structure, standardized mounting dimensions facilitate installation and daily maintenance; the installation requirements are consistent with ALP series, requiring the pump and motor shaft to be aligned with coaxiality controlled within 0.1mm.

9. Application Fields

10. Notes

• The parameters listed above are based on standard configuration; for customized products, parameters may vary slightly, please refer to the official product manual. The ALP3 series can be customized with different sealing materials or rotation directions according to application needs.
• It is recommended to use hydraulic oil that meets the viscosity requirements to ensure the long-term stable operation of the pump; the oil suction pipeline should be strictly sealed to prevent air leakage, and the pipeline diameter should not be smaller than the pump inlet diameter.
• During installation, please ensure that the mounting torque and shaft connection are correct to avoid equipment failure caused by improper installation; the pump should be installed close to the oil tank, and the suction height should not exceed 500mm to prevent cavitation.