Marzocchi pumps GHP1A-D-4-FG, GHP2A-S-40-FG

General Introduction

1. Model Nomenclature Explanation

1.1 GHP1A-D-4-FG Model Nomenclature

• GHP: Product series, indicating the high-pressure external gear pump, suitable for medium and high pressure hydraulic systems, with higher pressure-bearing capacity than ALP series.
• 1A: Size group, belonging to the GHP1 group, which determines the basic installation dimensions and maximum displacement of the pump, with a displacement range of 1~10 cm³/rev.
• D: Mounting method, standing for flange mounting, which is widely used in scenarios requiring stable and firm installation, ensuring minimal vibration during operation.
• 4: 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 GHP1 group.
• FG: Special options, where “F” means equipped with a pressure limiting valve (overload protection device), and “G” means adopting mechanical seal for better sealing performance, preventing oil leakage in high-pressure working conditions.

1.2 GHP2A-S-40-FG Model Nomenclature

• GHP: Product series, same as above, high-pressure external gear pump, suitable for medium and high pressure hydraulic systems.
• 2A: Size group, belonging to the GHP2 group, with a larger displacement range (10~50 cm³/rev) and installation dimensions than the GHP1 group.
• S: Mounting method, standing for shaft extension mounting, different from flange mounting (marked with “D”), suitable for scenarios where installation space is limited and flexible connection is required.
• 40: Displacement code, corresponding to the theoretical displacement of the pump (specific value refers to the technical specifications below), which is the upper limit of the GHP2 group’s displacement range.
• FG: Special options, same as above, equipped with a pressure limiting valve (“F”) and mechanical seal (“G”), consistent with the standard special configuration of Marzocchi GHP series pumps.

2. Basic Information

3. Key Technical Specifications

4. Material & Sealing

4.1 GHP1A-D-4-FG

• Pump Body & Covers: High-strength aluminum alloy, light weight, good corrosion resistance and pressure-bearing capacity, suitable for high-pressure small-flow working conditions, consistent with GHP series material standards. The flange is integrated with the pump body to enhance structural stability.
• Gears: Special hardened alloy steel, precision machined to minimize internal clearance, reduce internal leakage and improve transmission efficiency, which is the standard gear material for GHP series high-performance models.
• Sealing: Mechanical seal (marked with “G” in the model), with NBR sealing material as auxiliary, ensuring good sealing performance under high pressure, preventing oil leakage; the sealing configuration is consistent with the standard “FG” option of Marzocchi GHP series pumps.

4.2 GHP2A-S-40-FG

• Pump Body & Covers: High-strength aluminum alloy, same material as GHP1A-D-4-FG, but with a larger structure to adapt to larger displacement and torque, ensuring stable operation under high pressure and large flow.
• Gears: Special hardened alloy steel, same as GHP1A-D-4-FG, precision machined to adapt to larger displacement, ensuring low internal leakage and high transmission efficiency even under large flow conditions.
• Sealing: Mechanical seal (marked with “G” in the model), with NBR sealing material as auxiliary, optimized for large flow and high pressure working conditions, ensuring reliable sealing and no oil leakage during long-term operation.

5. Shaft & Mounting Details

5.1 GHP1A-D-4-FG (Flange Mounting, Code “D”)

• Shaft Type: Conical shaft with a taper of 1:8, equipped with a 4 mm key for stable power transmission, matching the small torque characteristics of the model.
• Shaft Dimensions: Shaft diameter is 18 mm, shaft length (including fitting edge) is 40 mm, fitting edge diameter is 45 mm; shaft thread size is M12×1.25, small size to adapt to the GHP1 group.
• Mounting Type: European standard 4-hole flange mounting, centering diameter is 45 mm, consistent with the mounting standard of GHP1 group flange-mounted pumps, ensuring firm installation and reducing vibration.
• Shaft Load & Torque: Maximum torque is 85 Nm, recommended shaft tightening torque is 60±5 Nm, matching the small displacement and low torque of the model.

5.2 GHP2A-S-40-FG (Shaft Extension Mounting, Code “S”)

• Shaft Type: Conical shaft with a taper of 1:8, equipped with a 6 mm key for stable power transmission, suitable for larger torque transmission required by large displacement.
• 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 size to adapt to the GHP2 group and larger torque.
• Mounting Type: Shaft extension mounting, flexible installation, suitable for scenarios with limited installation space; the mounting dimensions are consistent with the GHP2 group shaft extension mounting standard.
• Shaft Load & Torque: Maximum torque is 420 Nm, recommended shaft tightening torque is 85±5 Nm, matching the large displacement and high torque of the model.

6. Port Specifications

7. Operating Conditions

• Hydraulic Oil Viscosity: Allowed range is 6-500 cst; recommended range is 15-100 cst for optimal performance. GHP1A-D-4-FG is suitable for slightly higher viscosity oil (20-100 cst) due to small displacement, while GHP2A-S-40-FG is suitable for the standard recommended range (15-100 cst).
• Operating Temperature: -10°C to +80°C (pump start-up and continuous operation temperature range), consistent with GHP series overall operating temperature standard, suitable for most industrial working environments.
• 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 GHP series pumps.
• Suction Vacuum: Allowable suction vacuum is 110mm column for both models; GHP1A-D-4-FG has stronger self-priming capacity due to small displacement, while GHP2A-S-40-FG requires the suction pipeline to be strictly sealed to avoid cavitation.

8. Product Features

8.1 Common Features of Both Models

• High Pressure Resistance: Designed for high-pressure working conditions, maximum continuous pressure up to 250 bar, peak pressure up to 300 bar, suitable for medium and high pressure hydraulic systems.
• High Efficiency & Stability: Precision-machined gears with minimal internal clearance reduce internal leakage, ensuring high output efficiency and stable pressure supply.
• 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.
• Low Noise: Optimized gear meshing design and compact structure effectively reduce operating noise, suitable for noise-sensitive occasions.
• Easy Installation & Maintenance: Standardized mounting dimensions and compact structure facilitate installation and daily maintenance, reducing maintenance costs.

8.2 Unique Features of GHP1A-D-4-FG

• Small Size & Light Weight: Compact structure, light weight (approx. 3 kg), suitable for scenarios with limited installation space and small flow requirements.
• Strong Self-priming Capacity: Optimized for small displacement, can quickly suck hydraulic oil even under low-pressure conditions, adapting to various harsh working environments.
• High Precision: Suitable for precision hydraulic systems that require small and stable flow, such as precision instrument control and small hydraulic actuators.

8.3 Unique Features of GHP2A-S-40-FG

• Large Displacement & High Flow: Theoretical displacement up to 39.5 cm³/rev, flow rate up to 59.5 L/min (at 1500 rpm), suitable for large flow hydraulic systems.
• Flexible Installation: Shaft extension mounting design, suitable for scenarios with limited installation space and flexible connection requirements.
• Strong Torque Transmission: Larger shaft diameter and key size, maximum torque up to 420 Nm, able to meet the power transmission needs of large-flow hydraulic systems.

9. Application Fields

9.1 GHP1A-D-4-FG

9.2 GHP2A-S-40-FG

10. Installation Instructions

10.1 General Installation Requirements

• The pump should be installed in a dry, well-ventilated area, away from high-temperature heat sources and corrosive substances, to avoid damage to the pump body and seals.
• Ensure that the pump and motor shaft are aligned, with coaxiality controlled within 0.1mm, to avoid vibration and noise caused by misalignment, and prevent shaft damage.
• The oil suction pipeline should be strictly sealed to prevent air leakage; the pipeline diameter should not be smaller than the pump inlet diameter, and the pipeline should be as short as possible to reduce suction resistance.
• The pump should be installed close to the oil tank, and the suction height should not exceed 500mm to prevent cavitation and ensure normal oil suction.
• Before installation, check whether the pump is intact, whether the rotating parts are flexible, and whether there is any foreign matter in the pump body.

10.2 Installation of GHP1A-D-4-FG (Flange Mounting)

• Align the flange of the pump with the mounting base, ensure that the mounting holes are aligned, and use bolts to fix the pump, with the tightening torque controlled at 60±5 Nm.
• Connect the inlet and outlet pipelines to the pump ports, ensure that the pipeline connection is tight, and use sealing gaskets to prevent oil leakage.
• After installation, manually rotate the pump shaft to ensure that it rotates flexibly without jamming, and check whether the pipeline has loose connections.

10.3 Installation of GHP2A-S-40-FG (Shaft Extension Mounting)

• Fix the pump to the mounting base through the shaft extension part, ensure that the mounting is firm, and the tightening torque of the fixing bolts is controlled at 85±5 Nm.
• Connect the motor shaft to the pump shaft through a coupling, ensure that the coaxiality is within the required range, and avoid excessive torque during operation.
• Connect the inlet and outlet pipelines, ensure that the pipeline diameter matches the pump port size, and the connection is tight to prevent oil leakage under high pressure.
• After installation, manually rotate the pump shaft to check for jamming, and confirm that all connections are intact.

11. Operation Instructions

• Before starting the pump, check whether the hydraulic oil level in the oil tank is sufficient, and whether the oil viscosity meets the requirements; open the oil suction and discharge valves to ensure unobstructed oil circuit.
• Start the motor, let the pump run idly for 2-3 minutes, check whether the pump operates normally, whether there is abnormal noise, vibration or oil leakage.
• Gradually increase the system pressure to the working pressure, and check whether the pressure is stable, whether the flow rate meets the requirements, and whether the pressure limiting valve works normally.
• During operation, regularly check the operating temperature of the pump (not exceeding 80°C), the oil level of the oil tank, and the sealing condition of the pipeline and pump body.
• If abnormal phenomena such as excessive noise, vibration, oil leakage or pressure instability occur during operation, stop the pump immediately, check the cause and eliminate the fault before restarting.
• When stopping the pump, first reduce the system pressure to zero, then stop the motor, and close the oil suction and discharge valves.

12. Maintenance & Troubleshooting

12.1 Routine Maintenance

• Regularly replace the hydraulic oil: replace the hydraulic oil every 2000 hours of operation, and clean the oil filter at the same time to ensure the cleanliness of the hydraulic oil.
• Check the seals regularly: check the mechanical seal and auxiliary seals every 1000 hours of operation, and replace them in time if they are worn, aged or damaged to prevent oil leakage.
• Clean the pump body regularly: remove the dirt and oil stains on the pump body to facilitate heat dissipation and prevent corrosion.
• Check the gear and shaft regularly: check the wear of the gear and shaft every 3000 hours of operation, and replace them in time if there is excessive wear to avoid affecting the pump performance.

12.2 Common Troubleshooting

13. Notes

• The parameters listed in this manual are based on standard configuration; for customized products, parameters may vary slightly, please refer to the official product manual.
• It is strictly prohibited to operate the pump beyond the maximum pressure and speed range, otherwise it will cause damage to the pump and hydraulic system.
• Use hydraulic oil that meets the viscosity requirements, and avoid using contaminated or expired hydraulic oil to prevent wear of internal components.
• During maintenance, cut off the power supply and release the system pressure first to ensure operation safety.
• The pump should be stored in a dry, cool and ventilated place when not in use, and the inlet and outlet ports should be sealed to prevent foreign matter from entering the pump body.
• For faults that cannot be solved by the troubleshooting methods in this manual, please contact Marzocchi’s official after-sales service for professional maintenance.

14. Warranty Information