DHP 0.8 Axial Piston Pump (High Pressure Pump For Industrial Reverse Osmosis)

DHP 0.8 is a typical model of the DHP series of Axial Piston Pumps. Specifically designed for industrial reverse osmosis scenarios such as seawater desalination and industrial desalination, it is mainly used to transport low-viscosity corrosive fluids like seawater and industrial saline wastewater.

This pump operates based on the principle of axial piston pumps: it achieves fluid transportation by the reciprocating movement of plungers parallel to the drive shaft within plunger bores, which changes the volume of the pump cavity. Compared with traditional piston pumps, its key advantage lies in using the transported fluid itself as the lubricating medium, eliminating the need for a traditional lubricating oil tank and fundamentally avoiding oil leakage pollution. This makes it perfectly suitable for scenarios with high cleanliness requirements, such as seawater and industrial wastewater treatment. Additionally, it has a compact structure (weighing only 3.7 kg), high operating efficiency, and an integrated flushing check valve, which simplifies the design of reverse osmosis membrane systems, reduces installation space and costs, and is particularly suitable for small and medium-sized seawater desalination or industrial desalination equipment.

Core Adaptability Advantages

For seawater desalination and industrial desalination scenarios, DHP 0.8 has two core adaptability advantages:

1. Corrosion Resistance and Low Interference: Key components of the pump body are made of 2205 duplex stainless steel (SAF 2205/EN 1.4462/UNS 31803), which has excellent corrosion resistance to high-salinity media. The pulse during operation is much smaller than that of other pump types, with low vibration and noise (≤74 dB(A) in accordance with EN ISO 3744-2010 standard), making it suitable for industrial sites sensitive to the operating environment;

2. Flexible Adjustment: As a fixed-displacement pump, the flow rate is proportional to the rotational speed. The motor speed can be adjusted to match the flow requirements of different seawater desalination/industrial desalination systems. The flow rate reaches 0.81 m³/h at the rated speed of 3000 rpm, meeting the stable water supply needs of small and medium-sized systems.

Core Technical Parameters of DHP 0.8

Pump Flow Curve 

DHP 0.8 belongs to the DHP0.6～1.0 series and is a fixed-displacement pump. Under a working pressure of 80 Bar, the flow rate has a strictly proportional relationship with the rotational speed. The flow curve on Page 14 of the manual allows for intuitive query of the flow rate corresponding to different rotational speeds: the horizontal axis represents rotational speed (700～3450 rpm), and the vertical axis represents flow rate (0～1.25 m³/h). For example, at a rotational speed of 1500 rpm, the flow rate is approximately 0.4 m³/h; at 2500 rpm, it is approximately 0.675 m³/h; and when reaching the rated rotational speed of 3000 rpm, the flow rate stabilizes at 0.81 m³/h.

If it is necessary to calculate the target rotational speed based on actual needs, the formula provided in the manual can be used:
Selected Motor Speed (r/min) = (Required Flow Rate (m³/h) × Rated Speed 3000 (r/min)) / Rated Flow Rate 0.81 (m³/h)
For instance, when a seawater desalination system requires a flow rate of 0.5 m³/h, the required rotational speed is (0.5×3000)/0.81 ≈ 1852 rpm, making the calculation convenient.

Installation and Operation Instructions

Key Installation Requirements

• Interface Identification: The port marked "I" on the pump body is the inlet, and "O" is the outlet. The installation direction must be strictly distinguished to avoid damage to precision components inside the pump due to reverse connection;

• Motor coupling: A clearance of 3 to 5 mm should be maintained between the pump and motor coupling. The pump shaft must not be subjected to axial or radial loads (such as those generated by forced piping connections) to prevent premature wear of the shaft seal and bearings. The standard connection diagram for the motor and high-pressure pump is as follows:

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• Foundation and Piping: It is recommended to install the pump unit on a base with vibration dampers to reduce vibration transmission and noise; the diameter of the inlet pipe should not be smaller than the pump inlet size (G1/2〞), and bends and joints should be minimized to reduce pressure loss (to avoid cavitation caused by insufficient inlet pressure).

Operation Precautions Specific to Seawater Desalination/Industrial Desalination Scenarios

1. Filtration Configuration: Impurity particles (such as sediment and suspended solids) in seawater and industrial wastewater can wear the plungers and plunger sleeves inside the pump. A filter with an absolute accuracy of 10 μm (filtration efficiency ≥99.98%, β10>5000) must be installed before the pump inlet. Bag filters or spiral wound filters with only 90% efficiency are strictly prohibited (prone to particle leakage);

2. Pressure Protection: A low-pressure control switch (set to 1 Bar) should be installed at the inlet end, which will automatically shut down the pump when the inlet pressure is lower than this value to prevent pump idling (idling is likely to cause dry friction of plungers); a high-pressure control switch (set to 70 Bar) and a safety valve (pressure adjustment range 5～9 MPa, customizable) should be installed between the pump outlet and the reverse osmosis membrane to prevent damage to the membrane module or pipeline due to system overpressure;

3. Start-Up, Shutdown and Flushing: In high-salinity scenarios (such as seawater desalination), the pump cavity must be flushed with fresh water after each shutdown to discharge residual concentrated brine (long-term residual concentrated brine is likely to crystallize and block the flow channel); if the shutdown lasts more than 3 days, flushing with fresh water is required; if it lasts more than 15 days, flushing with fresh water containing a bactericide is necessary (to prevent microbial growth and corrosion); starting the pump with the rear valve closed is strictly prohibited, as this may trigger the safety valve or cause pipeline burst.

Power Parameters

The power of DHP 0.8 varies with the working pressure. The power requirement at the rated speed of 3000 rpm is as follows:

The working pressure of seawater desalination systems is usually 70～80 Bar, so a 3.0 kW motor is recommended to ensure stable pump operation without energy waste; for industrial desalination scenarios with lower pressure (e.g., below 60 Bar), a 2.2 kW motor can meet the requirements.

Dimensional Parameters

Inlet and Outlet Dimensions

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

The following are dimensional examples of DHP 0.8 matched with commonly used motors, which can be used for installation space planning:

High-Pressure Piston Pump Maintenance and Warranty Service (for DHP 0.8)

Daily Maintenance Key Points

• Lubrication Management: The transported fluid is used as the lubricating medium, so no additional lubricating oil is needed. Daily maintenance only requires judging whether to replace the filter element based on the filter pressure difference (excessive pressure difference indicates filter element blockage, which needs to be replaced in time to ensure clean inlet fluid);

• Regular Inspection: Under standard operating conditions (10 μm filtration, normal pressure/speed), a comprehensive inspection is recommended every 8000 hours. Focus on checking the sealing performance of the shaft seal (for leakage) and the wear of plungers and plunger sleeves (excessive wear will lead to reduced flow rate), and replace worn parts in a timely manner;

• Corrosion Protection: The pump body is made of 2205 duplex stainless steel (with excellent corrosion resistance), but in high-salinity scenarios such as seawater desalination, the shutdown flushing process must be strictly implemented to avoid local corrosion (such as pitting corrosion caused by salt accumulation on the inner wall of the flow channel) due to residual salt.

Warranty Service

• Basic Warranty: A 1-year free maintenance service is provided from the date of delivery (excluding faults caused by man-made damage or non-compliant operation, such as component wear caused by not installing a filter);

• Extended Protection: If the pump operates under specified conditions at all times (meeting filtration, pressure and speed requirements), it can enjoy an 8000-hour maintenance-free warranty, with a maximum period not exceeding 18 months from the date of delivery;

• After-Sales Support: The manufacturer provides fault detection, on-site maintenance, factory repair and spare parts supply services to ensure the continuous and stable operation of seawater desalination and industrial desalination systems. Support can be obtained through the contact information below.

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

Company Introduction

WUXI FENIGAL SCIENCE AND TECHNOLOGY CO., LTD. (FG Water Technologies), the manufacturer of DHP 0.8, has focused on the research and development of high-pressure piston pumps since 1990 and is the first domestic enterprise to produce axial high-pressure piston pumps. After nearly 15 years of in-depth cultivation and innovation, the enterprise has realized the localization of axial high-pressure piston pumps. Its technical level and product 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.

In collaboration with its OEM partner Shenzhen CW Environment Technology, the enterprise widely applies axial high-pressure piston pumps in fields such as seawater desalination, industrial desalination and membrane concentration. It always adheres to the tenet of "quality first, integrity-based, customer satisfaction", continuously improves the supply chain and sales service system, and is committed to providing customers with efficient core fluid equipment and technical solutions to support the implementation of the "Made in China 2025" strategy and industrial foundation strengthening strategy.

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