DHP 3.0 Axial Piston Pump（High Pressure Pump For Industrial Reverse Osmosis）

DHP 3.0 is a typical model of the DHP series Axial Piston Pumps, specifically engineered for handling high-pressure, low-viscosity corrosive fluids. It plays a crucial role in industrial reverse osmosis scenarios, with core applications focusing on seawater desalination and industrial desalination—effectively conveying media like seawater, brackish water, and industrial saline wastewater.

Following the axial piston pump principle, the pump operates via the reciprocating motion of plungers parallel to the drive shaft within plunger bores. This motion changes the pump cavity volume to achieve fluid transfer. A key advantage over traditional piston pumps is that it eliminates the need for a lubricating oil tank; instead, it uses the conveyed fluid itself as the lubricating medium. This design not only simplifies the structure but also completely avoids oil leakage pollution, making it highly suitable for the strict cleanliness requirements of seawater desalination and industrial desalination systems. Additionally, it features a compact structure—smaller in size and lighter in weight compared to other pumps with the same flow rate and pressure—and offers high operating efficiency, which helps reduce long-term energy consumption costs for users.

Core Technical Parameters of DHP 3.0

Pump Flow Curve

DHP 3.0 belongs to the DHP1.7～3.0 product series, and like other models in this series, it is a fixed-displacement pump. Under a working pressure of 80 Bar, its flow rate has a strict proportional relationship with the input shaft speed.

The flow curve on the specified pages of the manual clearly reflects this relationship: the horizontal axis represents the pump speed (ranging from 700 rpm to 3450 rpm), and the vertical axis represents the flow rate (ranging from 0 m³/h to 3.5 m³/h). For example, when the speed is 1500 rpm, the flow rate of DHP 3.0 is approximately 1.5 m³/h; when the speed reaches the rated 3000 rpm, the flow rate stabilizes at the rated 3.0 m³/h.

To calculate the required motor speed for a specific flow demand, the manual provides a formula: Selected motor speed (r/min) = (Required flow rate (m³/h) × Rated speed (3000 r/min)) / Rated flow rate (3.0 m³/h). For instance, if a flow rate of 2.2 m³/h is needed, the calculated motor speed is approximately 2200 rpm, ensuring accurate matching of system flow requirements.

Installation and Operation Instructions

Key Installation Requirements

• Interface Identification: The port marked "I" on the pump body is the inlet, and the port marked "O" is the outlet. During installation, it is essential to confirm the correct connection direction to avoid reverse connection, which may cause internal component damage or system failure.

• Motor coupling installation: A clearance of 3-5 mm must be maintained between the pump and motor coupling. In addition, the pump shaft must not be subjected to any axial or radial loads, as this will affect the service life of the shaft seal and bearings. The standard connection method of the motor and high-pressure pump is shown in the figure below:

Operation Precautions for Seawater Desalination & Industrial Desalination

1. Filtration Requirement: Seawater and industrial wastewater often contain solid particles that can wear the pump's plungers and plunger sleeves. A filter with an absolute precision of 10 μm (filtration efficiency ≥99.98%, β10>5000) must be installed at the pump inlet. It is not recommended to use bag filters or spiral wound filters with only 90% filtration efficiency, as they cannot effectively block fine particles.

2. Pressure Protection Configuration: A low-pressure control switch should be installed between the filter and the pump inlet, set to a trigger pressure of 1 Bar. If the inlet pressure drops below this value, the switch will automatically shut down the pump to prevent dry running. A high-pressure control switch (set to 70 Bar) and a safety valve must be installed between the pump outlet and the reverse osmosis membrane. This prevents system overpressure from damaging the membrane module or pipelines.

3. Shutdown Flushing Protocol: In high-salinity environments (e.g., seawater desalination), the pump cavity must be flushed with fresh water immediately after each shutdown to discharge residual concentrated brine—this avoids salt crystallization and internal corrosion. If the shutdown period exceeds 3 days, a thorough fresh water flush is required; if it exceeds 15 days, flushing with fresh water containing a bactericide is necessary. Starting the pump with the downstream valve closed is strictly prohibited, as this may lead to safety valve activation or pipeline rupture.

5. Power Parameters 

The power consumption of DHP 3.0 varies with the working pressure. The following is the power parameter table:

In practical applications, for example, in seawater desalination systems where the working pressure is usually 70-80 Bar, selecting an 11 kW motor ensures the pump operates stably without insufficient power or energy waste.

Dimensional Parameters

DHP 3.0 shares the same dimensional specifications as the DHP1.7～3.0 series. The specific dimensions are as follows, which are essential for on-site installation space planning:

Inlet and Outlet Dimensions

Overall Dimensions (with Independent Fan Motor/Inverter Motor, Unit: mm)

The overall dimension diagram of the DHP1.7～3.0 series is provided on Pages 25-26 of the manual. Below are dimension examples for DHP 3.0 matching commonly used motors, facilitating installation layout:

High-Pressure Piston Pump Maintenance and Warranty Service (for DHP 3.0)

Daily Maintenance Key Points

• Lubrication Management: DHP 3.0 relies on the conveyed fluid for lubrication, eliminating the need for lubricating oil addition. Daily maintenance only requires confirming that the inlet fluid is clean and free of impurities, without additional lubrication operations.

• Regular Inspection: Under standard operating conditions (compliant with 10 μm filtration, rated pressure, and speed), it is recommended to conduct a comprehensive inspection of the pump every 8000 hours. Focus on checking the wear of components such as the shaft seal, plunger, and check valve; replace worn parts promptly to prevent minor faults from escalating into major failures.

• Corrosion Prevention: Although the pump body is made of 2205 duplex stainless steel with excellent corrosion resistance, in high-salinity working environments, residual salt may accumulate if flushing is insufficient after shutdown. 

Warranty Service Details

• Basic Warranty: From the date of the pump’s factory shipment, DHP 3.0 is entitled to a 1-year free maintenance service. This service covers faults caused by product quality issues but excludes damage resulting from human error, improper operation, or non-compliance with maintenance requirements.

• Extended Protection: If the pump operates continuously under the specified conditions (standard filtration, pressure, and speed), it can enjoy an 8000-hour maintenance-free warranty. Note that the maximum duration of this extended warranty does not exceed 18 months from the date of production.

• After-sales support: The manufacturer provides comprehensive after-sales service, including on-site fault diagnosis, on-site maintenance, factory repairs, spare parts supply, etc. If you have any maintenance needs, users can contact us through the following contact information.

Manufacturer's Contact Information

• Company: WUXI FENIGAL SCIENCE AND TECHNOLOGY CO., LTD. (FG Water Technologies)

• Address: Chuangyi Industrial Park, No. 100 Dicui Road, Binhu District, Wuxi City, Jiangsu Province, P. R. China

• Tel: +86-510-85163211

• Mobile: +86-13646187144

• Email: [email protected]

• Official Website: https://www.fgwater.com

Enterprise Introduction

FENIGAL, the manufacturer of DHP 3.0, has been committed to the research and development of high-pressure piston pumps since 1990 and is the first domestic enterprise to engage in the development of axial high-pressure piston pumps. After nearly 15 years of focused innovation and technical accumulation, FENIGAL successfully achieved the localization of axial high-pressure piston pumps. Its product technical level and quality have reached world advanced standards, and its production scale ranks among the top in the domestic industry, effectively solving the bottleneck problem of relying on imported products in related fields.

FENIGAL adheres to the tenet of "quality first, integrity-based, customer satisfaction" and cooperates with its OEM partner Shenzhen CW Environment Technology to provide high-quality axial piston pumps for global users. The company’s products are widely used in seawater desalination, industrial desalination, membrane concentration, and high-hygiene cleaning fields. While continuously enhancing core competitiveness, FENIGAL also improves its supply chain and sales service systems, dedicated to providing customers with efficient core fluid equipment and professional technical solutions to support the implementation of the "Made in China 2025" strategy.

PDF manual download address:DHP type plunger pump selection manual