High Pressure Pumps for Desalination DHP4.5-8.2

Overview

The reverse osmosis desalination pump DHP4.5, DHP5.3, DHP6.3, DHP7.2, DHP8.2 series are positive displacement pumps with 9-pistons that move a fixed amount of water in each cycle. The best high pressure water pumps are based on the axial piston principle enabling a very light and compact design. Flow is proportional to the number of input shaft revolutions(rpm). Unlike centrifugal pumps, they produce the same flow at a given speed no matter what the discharge pressure.

The DHP4.5, DHP5.3, DHP6.3, DHP7.2, DHP8.2 range of best high pressure water pumps is designed for use in RO applications with low viscosity and corrosive fluids such as: Sea water (in seawater reverse osmosis filtration applications), Brackish water (high-pressure saltwater pumping), Waste water.

The DHP4.5, DHP5.3, DHP6.3, DHP7.2, DHP8.2 series best high pressure water pumps are supplied with an integrated flushing valve that allows the salt water to flow from inlet to the outlet, when the pump is not running.

Advantages (Hot Sale High Pressure Water Pumps)

√ Simple structure, small size, light weight, one of the smallest and lightest pumps on the market

√ Low pressure fluctuation, high working pressure

√ If a special coupling is used, it can be driven by an internal combustion engine

√ No need for lubricating oil, long maintenance period, no preventive maintenance during the warranty period

√ The pressure pulse generated in the pressure pipe is extremely small

√ Integrated flushing check valve, no need for additional installation

√ All parts of the pump are made of corrosion-resistant materials such as duplex (SAF 2205 / EN 1.4462 / UNS 31803) and super duplex (SAF 2507 / EN 1.4410 / UNS 32507) stainless steel, and carbon fiber reinforced polyether ether ketone (PEEK)) production

√ Efficient

Technical Specification Sheet

Flow rate at different speeds

If the required flow rate and speed (rpm) are known, it will be easy to select the most suitable pump by using the diagram below:

Not only that, the graph also shows that the flow rate can vary with the speed of the best high volume high pressure water pumps. The flow/speed ratio is fixed, and the required flow can be obtained by changing the speed to the corresponding value.

Power Requirement

Inlet pressure

The desalination pump DHP series can directly supply water from the feed water pump, and the pressure of the water inlet of the ro high pressure pump must be within the range of 2-5Bar (0.2-0.5Mpa or 29-72.5psi).

Unit conversion relationship: 1.0Mpa=10Bar, 1.0Mpa=145psi

Temperature and corrosion

Best High Pressure Water Pumps Operation

Fluid temperature: +2°C ～ +50°C-depends on the concentration of NaCl

Ambient temperature: +2°C ～ +50°C

The following figure shows the relationship between the corrosion resistance of different types of stainless steel and the concentration of NaCl and temperature.

All key components of DHP series high pressure pump for seawater reverse osmosis are made of 2507.

If the desalination pump is running under conditions of high salt content, fresh water should be used to flush the ro high pressure pump during shutdown to reduce the risk of corrosion.

Best High Pressure Water Pumps storage

Storage temperature: -40°C to +70°C (the ro high pressure pump has been emptied and sealed for storage).

Antifreeze is required when the temperature is lower than 2°C; It is recommended to use Dow Cal-N from DuPont Chemical Company or Chill safe Propylene Glycol from Ark man Chemical Company.

Noise

Under normal circumstances, the noise will be reduced when the speed is reduced, and vice versa. Flexible hoses can be used to minimize vibration and noise.

As the ro high pressure pump (group) is usually installed on a bell-shaped cover or base, the noise level can only be determined by the entire system. Therefore, the correct use of shock absorbers to install the pump set on the base is extremely important to reduce vibration and noise.

The noise level is affected by the following factors:

The speed of the pump, high speed produces more noise than low speed

The rigid installation of the pump generates more noise than the flexible installation

Compared with the connection through a hose, the direct connection of the pipe to the pump will increase the noise

Filtration

Because the viscosity of water is very low, in order to control the internal leakage rate and improve the performance of the components, the gap of the DHP series ro high pressure pump is designed to be very small. Therefore, proper filtration of inlet water is essential to minimize pump wear.

The main filter must have a filtration efficiency of 99.98% for particles above 10 µm. It is recommended to use a precision depth filter element with a rated accuracy of 10 µm (absolute accuracy) and ß10>5000 (equivalent to a filtration efficiency of 99.98%). Filter bags and wound filter elements usually only have a filtration efficiency of 90%, which means that for every 100,000 particles that reach the filter, 10,000 pass through. Relatively speaking, only 20 pass through a filter with an efficiency of 99.98%.

Dimensions

Outline and Installation Dimensions of Complete Equipment Including Motor

Complete Equipment without Independent Fan Motor

Unit: mm

Complete Equipment with Independent Fan Motor

Unit: mm

Installation

Assembly

The figure below shows how the pump is connected to the motor

A: Pump spindle

B: Flexible coupling

C: Bell cover

Note: There should be no axial or radial load on the pump shaft.

Reverse Osmosis System Using DHP Series RO High Pressure Pump

① in order to facilitate system flushing and discharge, the ro high pressure pump has integrated a bypass check valve (5) inside the pump.

② Install the inlet filter (1) before the ro high pressure pump (2). Please refer to section 2.8-"Filtering" for instructions on how to select the appropriate filter. Thoroughly clean the pipeline and flush the system before starting.

③ Install a low pressure control switch (3) between the filter and the pump inlet and set 1 Bar (14.5 psi) as the control point. When the pressure is lower than 1 Bar (14.5 psi), the low-pressure switch must be able to shut down the pump.

④ Install a high pressure control switch (7) between the pump outlet and the reverse osmosis membrane inlet, and set 70 Bar (1015 psi) as the control point. When the pressure is higher than 70 Bar (1015 psi), the high-pressure switch must be able to shut down the pump.

⑤ Determine the size of the inlet pipe to minimize the pressure loss (large flow area, short pipe length, as few elbows/joints as possible, and accessories with small pressure loss).

⑥ To eliminate the risk of damage and cavitation, the inlet should always be at positive pressure: minimum 0.5 Bar (7.3psi), maximum 5 Bar (72.5 psi)

⑦ Use elastic hose (4) to minimize vibration and noise.

⑧ Install the safety valve (6) to avoid damage to the system, because the high pressure piston pump will generate pressure and flow immediately after starting without being affected by any reverse pressure.

Service

The meticulous design makes the DHP series high pressure pump for seawater reverse osmosis have a long running time, low maintenance requirements, and reduce life cycle costs.

If the DHP series ro high pressure pump runs under the specified pre-filtration, pressure and speed conditions, an 8000-hour maintenance-free warranty is provided, but the maximum period from the date of production does not exceed 18 months.

In order to prevent the pump from being completely damaged, it is recommended that you inspect the pump at most 8000 hours, at which time any worn parts must be replaced.

Although the DHP series high pressure pumps for reverse osmosis are made of duplex/super duplex stainless steel with excellent corrosion resistance, it is always recommended to flush the ro high pressure pump with fresh water when the system is shut down.

Maintenance

DHP series ro high pressure pump for seawater reverse osmosis uses water as lubricant, so there is no oil in the pump.

If the ro high pressure pump runs under the curve of SAF 2507 shown in section 2.6, it is not expected that parts need to be replaced during the initial 8000 hours of operation.

China sea water desalination pump

DHP4.5~8.2 vs. APP5.1~10.2 high pressure pump