1. Safety Precautions

• Ensure the hydraulic system is completely shut down, and the pump is disconnected from the power source (motor, engine, etc.). Lock out and tag out the power supply to prevent accidental startup during service, in compliance with Danfoss safety standards.
• Relieve all system pressure before opening any components. Slowly loosen the pressure relief valve or a fitting to release pressure gradually; do not open high-pressure lines suddenly to avoid hydraulic fluid spray, which may cause severe burns.
• Wear appropriate personal protective equipment (PPE), including safety glasses, nitrile gloves, and oil-resistant clothing, to protect against hydraulic fluid contact, moving parts, and sharp components. Avoid direct contact with hot hydraulic fluid.
• Use only genuine Danfoss replacement parts and recommended tools specified in Danfoss technical documentation. Non-genuine parts or improper tools may cause component failure, safety hazards, or void the product warranty.
• Work in a well-ventilated area. Avoid contact with hot hydraulic fluid (temperatures exceeding 60°C/140°F), as it can cause burns. Clean up any fluid spills immediately to prevent slips and falls, and dispose of used hydraulic fluid in accordance with local environmental regulations.
• Do not modify the pump or its components without authorization from Danfoss. Modifications may void the warranty and compromise the pump’s performance, safety, and compliance with industry standards.
• After service, inspect all connections, seals, and components for proper installation before restarting the system. Test the pump under low pressure first (20-30% of maximum operating pressure) to check for leaks or abnormalities.

2. Product Overview

2.1 Main Series and Key Specifications

2.1.1 Axial Piston Pumps

• PVG Series (PVG 32, PVG 100, PVG 120, PVG 160): Variable displacement axial piston pumps designed for open circuit applications. Maximum working pressure ranges from 280bar (PVG 32) to 350bar (PVG 160), with maximum displacement from 32ml/rev (PVG 32) to 160ml/rev (PVG 160). Equipped with Danfoss’ advanced load-sensing technology for energy savings and precise control.
• Sauer-Danfoss Series (90R, 90M, 90L): Heavy-duty axial piston pumps for closed and open circuit applications. Maximum working pressure up to 420bar, with displacement ranging from 10ml/rev (90R) to 160ml/rev (90L). Ideal for harsh industrial and mobile environments, with high durability and reliability.

2.1.2 Vane Pumps

• SVP Series (SVP 16, SVP 25, SVP 40): Single vane pumps with fixed displacement. Maximum working pressure ranges from 160bar to 210bar, with maximum displacement from 16ml/rev to 40ml/rev. Compact design, low noise, and suitable for light to medium industrial applications.
• T Series (T 6, T 7, T 9): Dual and triple vane pumps with independent pressure and displacement sections. Maximum pressure for each section is 210-250bar, and maximum displacement ranges from 20-120ml/rev (P1) and 10-60ml/rev (P2/P3). Widely used in mobile machinery such as excavators and loaders.

2.1.3 Gear Pumps

• DP Series (DP 10, DP 20, DP 30): External gear pumps with fixed displacement. Maximum working pressure up to 200bar, with displacement ranging from 10ml/rev to 30ml/rev. Simple structure, easy maintenance, and suitable for low to medium pressure applications such as lubrication systems and small hydraulic circuits.

2.2 Common Model Examples

• PVG Series: PVG 32-2L/100-0-N-1R-10-C-000, PVG 120-2L/125-0-N-1R-10-C-000
• Sauer-Danfoss Series: 90R100KP1NN80S5C1E00, 90M055KP1NN80S5C1E00
• Vane Pumps: SVP 25-1R00-A1M1, T 7B-B10-1R00-A1M1
• Gear Pumps: DP 20-1R00-A1M1, DP 30-1R00-A1M1

3. Installation Guidelines

3.1 Mounting Requirements

• The pump can be mounted in any orientation (horizontal, vertical, or inclined). The mounting hub and flange comply with SAE or ISO standards. Ensure the mounting surface is clean, flat, and free of debris to prevent vibration and misalignment, which can cause bearing wear.
• Align the pump shaft with the driving shaft (motor/engine) accurately. Use a dial indicator to check alignment; the maximum allowable misalignment is 0.005” TIR (0.127mm). For rigid connections without a flexible coupling, ensure the mounting pad or adapter is concentric with the pump shaft to avoid bearing failure.
• The pump should not bear the load of the pipelines. Install supports for inlet and outlet lines to prevent stress on the pump ports, which can cause leaks or port damage.
• Provide sufficient space around the pump for maintenance and inspection (minimum 150mm clearance on all sides). Keep the area clean and free of obstacles to facilitate service operations.

3.2 Shaft Connection

• Splined Shaft: The maximum allowable misalignment is 0.005” TIR (0.127mm). Angular misalignment at the male and female spline axes must be less than ±0.0015” per inch radius (0.0015mm per mm radius). Lubricate the coupling interface with Danfoss-recommended lithium grease (Part No. 153B0001). The female coupling should be hardened to 28-46 RC and comply with SAE-J 498 B (1971) Class 1 flat root side fit.
• Keyed Shaft: Use high-strength heat-treated keys (Danfoss Part No. 132B0002). Replacement keys must be hardened to 28-35 RC, with key corners chamfered 0.03”-0.04” (0.75-1mm) at 45° to clear keyway radii.
• Side Load Limits: C-flange pumps can accept a side load of 165 lb (75 kg), and D-flange pumps can accept 210 lb (95 kg) at the center of the spline or key, with a B10 life of 12,000 hours at 1800 rpm.

3.3 Piping and Fluid Connections

• Connect inlet and outlet lines to the pump’s port block. Ensure the pipeline size matches the port size to avoid flow restrictions and pressure loss. Use clean, debris-free pipelines; flush new pipelines with Danfoss flushing fluid (Part No. 163B0001) before connection to prevent contamination.
• Case Pressure Limits: Maximum continuous case pressure is 70 psi (4.8 bar), and maximum intermittent case pressure is 120 psi (8.3 bar). Case pressure must never exceed inlet pressure by more than 20 psi (1.4 bar).
• Case Drain Line: Ensure the drain plumbing passes above the highest point of the pump before connecting to the reservoir. If not, install a 4 psi (0.28 bar) case pressure check valve (Danfoss Part No. 142B0001) to keep the case filled with oil at all times. The case leakage line must be large enough to prevent back pressure exceeding 70 psi (4.8 bar) and should be returned to the reservoir below the oil surface.
• Install a filter in the suction line (effective cross-section 2-3 times larger than the suction pipe) with a 10-micron rating (Danfoss Part No. 173B0001) to prevent debris from entering the pump.

4. Maintenance and Servicing

4.1 Maintenance Schedule

4.2 Fluid Requirements

• Use high-quality hydraulic oil that meets Danfoss’ specifications (ISO VG 46 or ISO VG 68 is recommended for most applications; Danfoss Hydraulic Oil 46/68 is preferred). The oil should have a high viscosity index and good anti-wear, anti-oxidation, and anti-rust properties.
• Viscosity Range: 15 to 380 cSt (at operating temperature). Avoid using oil with excessive viscosity (may cause cavitation) or too low viscosity (may reduce lubrication and increase wear).
• Fluid Cleanliness: Maintain fluid cleanliness to ISO 13/10 (NAS 7) for new installations and ISO 15/12 (NAS 9) for regular operation. Contamination is a major cause of pump failure, so regular filter replacement is critical.
• Prohibited Fluids: Do not use water-containing fluids, highly solvent-based fluids, or contaminated oil. Water can corrode internal components, while solvents can damage seals and gaskets. Do not mix different types of hydraulic oil.

4.3 Key Maintenance Procedures

4.3.1 Fluid Change

1. Shut down the system and relieve all pressure.
2. Disconnect the drain line from the reservoir and drain the old oil into a suitable container for disposal (follow local environmental regulations).
3. Flush the reservoir and pipeline with Danfoss flushing fluid to remove debris and old oil residue. Circulate the flushing fluid for 10-15 minutes at low pressure.
4. Reconnect the drain line and refill the reservoir with the recommended Danfoss hydraulic oil to the correct level.
5. Start the system and run it at low pressure for 5-10 minutes to circulate the new oil. Check for leaks and recheck the oil level.

4.3.2 Seal Replacement

1. Shut down the system, relieve pressure, and disconnect the pump from the power source and pipelines.
2. Remove the pump from the mounting bracket and disassemble the pump housing (follow the disassembly procedure in Section 5).
3. Carefully remove the old seals (use a Danfoss seal removal tool, Part No. 183B0001, to avoid damaging the pump housing or shaft).
4. Clean the seal grooves and mating surfaces with a lint-free cloth. Ensure no debris or residue remains; use Danfoss cleaning solvent (Part No. 193B0001) if necessary.
5. Install new seals (apply a thin layer of Danfoss hydraulic oil to the seals for lubrication during installation).
6. Reassemble the pump, reconnect it to the system, and test for leaks at low pressure.

5. Disassembly and Reassembly

5.1 Preparation for Disassembly

• Shut down the system, relieve all pressure, and disconnect the pump from the power source and pipelines.
• Drain all hydraulic oil from the pump and clean the exterior of the pump to prevent debris from entering during disassembly.
• Gather the required tools: Danfoss-specified socket set, torque wrench (Part No. 203B0001), screwdrivers, seal removal tool, bearing puller (if needed), and a clean workbench.
• Label all components (e.g., bolts, gears, vanes) as you remove them to ensure correct reassembly. Take photos if necessary for reference.

5.2 Disassembly Procedure

1. Remove the mounting bolts and separate the pump from the mounting bracket.
2. Remove the end cover bolts and carefully separate the end cover from the pump housing. Note the position of gaskets or O-rings between the end cover and housing (replace with new Danfoss parts during reassembly).
3. For vane pumps: Remove the rotor, vanes, and cam ring from the housing. Inspect the vanes for wear, cracks, or damage (replace with Danfoss Part No. 213B0001 series if necessary). Check the cam ring for scoring or wear.
4. For piston pumps: Remove the cylinder block, pistons, swashplate, and valve plate. Inspect the pistons for wear or damage, and check the swashplate and valve plate for scoring or uneven wear (replace with genuine Danfoss components if needed).
5. Remove the shaft seal from the end cover (use a Danfoss seal removal tool). Inspect the pump shaft for wear, scratches, or bending; replace the shaft if damaged (Danfoss Part No. 223B0001 series).
6. Remove the bearings (if applicable) using a bearing puller. Inspect the bearings for noise, wear, or damage; replace with Danfoss-specified bearings (Part No. 233B0001 series) if necessary.
7. Clean all disassembled components with Danfoss cleaning solvent. Dry thoroughly with a lint-free cloth. Do not use compressed air to dry components (may force debris into small gaps).

5.3 Reassembly Procedure

1. Install new bearings (if replacing) into the pump housing and end cover. Ensure the bearings are pressed into place correctly (use a bearing press if needed).
2. Install the new shaft seal into the end cover (apply a thin layer of Danfoss hydraulic oil to the seal lip for lubrication).
3. For vane pumps: Insert the cam ring into the pump housing. Install the rotor onto the shaft, then insert the vanes into the rotor slots (ensure the vanes are oriented correctly). Apply a thin layer of Danfoss hydraulic oil to the vanes and cam ring.
4. For piston pumps: Install the valve plate into the pump housing. Mount the swashplate and cylinder block, then insert the pistons into the cylinder block (ensure the pistons are seated correctly).
5. Position the end cover with a new gasket or O-ring (genuine Danfoss part) and secure it with bolts. Tighten the bolts evenly in a crisscross pattern to the recommended torque (refer to Section 7 for torque specifications).
6. Reinstall the pump onto the mounting bracket and secure it with bolts. Tighten the bolts to the recommended torque.
7. Reconnect the inlet, outlet, and case drain lines. Ensure all connections are tight and secure.

6. Troubleshooting

7. Technical Specifications and Torque Requirements

7.1 General Technical Specifications

• Maximum Operating Temperature: 85°C (185°F) (intermittent); 65°C (149°F) (continuous)
• Minimum Operating Temperature: -25°C (-13°F) (with Danfoss low-temperature hydraulic oil, Part No. 253B0001)
• Shaft Speed Range: 500-3000 rpm (varies by series; refer to model-specific data)
• Filtration Requirement: Minimum 10-micron filter (recommended 5-micron for critical applications; Danfoss Part No. 173B0001 series)

7.2 Torque Specifications (Typical Values)

• End Cover Bolts: 28-38 N·m (21-28 ft-lb)
• Mounting Bolts: 42-52 N·m (31-38 ft-lb)
• Shaft Nut: 85-105 N·m (63-77 ft-lb)
• Pipeline Fittings: 16-26 N·m (12-19 ft-lb) (depends on fitting size)

8. Parts and Accessories

• Shaft seals, O-rings, and gaskets (Danfoss Part No. 122B0001 series)
• Vanes, rotors, and cam rings (vane pumps) (Danfoss Part No. 213B0001 series)
• Pistons, cylinder blocks, swashplates, and valve plates (piston pumps) (Danfoss Part No. 263B0001 series)
• Bearings and bushings (Danfoss Part No. 233B0001 series)
• Filter elements (Danfoss Part No. 173B0001 series)
• Pressure relief valves (Danfoss Part No. 243B0001 series)

9. Warranty Information

• Improper installation, operation, or maintenance not in accordance with this manual
• Use of non-genuine parts or incorrect hydraulic oil
• Contamination, overheating, or excessive load
• Unauthorized modifications or repairs
• Damage caused by external factors (e.g., impact, corrosion, or improper storage)