Stainless Steel Submersible Seawater Pump for Seawater Intake and Transfer

The stainless steel submersible seawater pump is designed for seawater intake, saltwater transfer and coastal water supply applications. The pump and submersible motor form an integrated unit that operates directly underwater, making it suitable for seawater desalination plants, ports, aquaculture facilities, offshore projects and coastal industrial systems.

Depending on the water chemistry and operating conditions, the pump can be manufactured in SS316L, duplex stainless steel 2205 or super duplex stainless steel 2507. Flow rate, head, power, voltage, frequency, cable length and installation method can be customized according to project requirements.

Product Overview

The QJH stainless steel submersible seawater pump uses a multistage centrifugal design. Water passes through multiple impellers, with pressure increasing at each stage. This structure makes the pump suitable for projects requiring high head, deep installation or long-distance water transfer.

The pump and motor are directly connected, eliminating the need for a long transmission shaft or a complicated suction pipeline. The complete unit can be installed vertically in a seawater well, intake chamber or collection tank. Selected models can also be installed horizontally with a properly designed motor cooling sleeve.

Available Technical Configurations

The following specifications can be selected according to the operating conditions:

• Pump type: Multistage submersible seawater pump
• Pump series: QJH series
• Pumped liquid: Seawater, saltwater and other compatible corrosive liquids
• Available materials: SS316L, duplex stainless steel 2205 and super duplex stainless steel 2507
• Installation: Vertical submersible installation or horizontal installation with a cooling sleeve
• Power supply: Three-phase AC
• Frequency: 50 Hz or 60 Hz
• Available voltage: 380 V, 400 V, 415 V, 440 V, 460 V, 660 V, 690 V or customized voltage
• Discharge connection: Flanged outlet
• Cable length: Customized according to installation depth
• Starting method: Direct-on-line, soft starter or variable-frequency drive

The required flow rate, head, motor power, discharge diameter and pump dimensions should be determined according to the actual intake capacity, elevation difference, pipeline losses and water conditions.

Main Product Features

Corrosion-Resistant Construction

The hydraulic components can be manufactured from SS316L, duplex stainless steel 2205 or super duplex stainless steel 2507. Selecting the appropriate material helps reduce the risk of pitting, crevice corrosion and premature deterioration in seawater environments.

Multistage High-Head Design

Multiple impellers operate in series to increase the discharge pressure. This design is suitable for deep seawater extraction, high-head water delivery and long-distance pipeline transfer.

Integrated Pump and Motor

The pump is directly connected to the submersible motor, creating a compact pumping unit. No surface suction system or long drive shaft is required, simplifying installation in wells and intake structures.

Customized for Project Conditions

Pump materials, motor power, cable length, seals, control panels and installation accessories can be selected according to seawater temperature, salinity, chloride concentration, installation depth and required operating time.

Factory Performance Testing

Before shipment, the pump can be tested to verify its flow rate, head, power consumption, current, vibration and sealing performance. Test requirements can be agreed upon according to the project specifications.

Typical Applications

The stainless steel submersible seawater pump is suitable for:

• Seawater intake for desalination plants
• Reverse osmosis pretreatment systems
• Port and coastal engineering projects
• Offshore platform water intake
• Marine and shipboard auxiliary systems
• Seawater supply for aquaculture
• Coastal industrial cooling systems
• Island water supply projects
• Saltwater and brackish water transfer
• Seawater wells and beach filtration wells

Stainless Steel Material Selection

SS316L Stainless Steel

SS316L can be used for certain saltwater and seawater conditions. Its suitability depends on the chloride concentration, liquid temperature, flow velocity, oxygen content and operating period. A water analysis should be reviewed before final material selection.

Duplex Stainless Steel 2205

Duplex stainless steel 2205 provides higher mechanical strength and better resistance to chloride-induced corrosion than conventional austenitic stainless steel. It is suitable for many coastal intake and saltwater transfer projects.

Super Duplex Stainless Steel 2507

Super duplex stainless steel 2507 offers stronger resistance to pitting and crevice corrosion. It is commonly considered for high-salinity water, elevated chloride levels and demanding marine projects.

Material selection should not be based only on the general description of “seawater.” The complete water analysis, operating temperature, duty cycle and expected service life should also be evaluated.

Information Required for Pump Selection

To select the correct submersible seawater pump, please provide:

1. Required flow rate in m³/h
2. Required head in meters
3. Pipeline length and diameter
4. Number of valves, elbows and fittings
5. Seawater temperature and water analysis
6. Sand or solid particle content
7. Installation depth and well diameter
8. Voltage, frequency and number of phases
9. Daily operating time and starting frequency
10. Required material and installation method

This multistage pump is intended primarily for relatively clean seawater or saltwater. If the liquid contains large quantities of sand, fibers or solid particles, a pump designed for abrasive or wastewater service should be selected.

Installation and Maintenance

Before installation, inspect the cable, insulation resistance, fasteners, lifting equipment and electrical connections. Never lift or suspend the pump by its power cable.

During operation, the pump should remain at the specified submerged depth. Voltage, current, flow rate and discharge pressure should be monitored regularly. For horizontal installation, an appropriately designed cooling sleeve may be required to maintain sufficient water flow around the motor.

In seawater service, the impellers, diffusers, shaft, fasteners, cable and sealing areas should be inspected according to the maintenance schedule. If the pump will remain unused for an extended period, freshwater flushing and appropriate corrosion protection are recommended.

Frequently Asked Questions

Can this pump operate directly in seawater?

Yes. However, the material must be selected according to the salinity, chloride concentration, temperature and operating time. Duplex 2205 or super duplex 2507 should be evaluated for long-term or demanding seawater service.

Can it be used in a seawater desalination plant?

Yes. It can be used for raw seawater intake or water transfer within a desalination pretreatment system. The final model depends on the required flow, head, pipeline losses and water quality.

Is a 60 Hz motor available?

Yes. Both 50 Hz and 60 Hz motors are available. Voltages such as 440 V, 460 V and 690 V can also be supplied according to project requirements.

Can the pump be installed horizontally?

Selected models can be installed horizontally with a cooling sleeve. The design must ensure sufficient water movement around the motor for effective cooling.

How can I obtain an accurate quotation?

Please provide the required flow, head, voltage, frequency, installation depth, water analysis, material preference and order quantity. A suitable pump model and technical quotation can then be prepared.

Request Pump Selection and Quotation

We provide stainless steel submersible seawater pump selection support for desalination plants, port projects, aquaculture facilities, offshore engineering and coastal industrial applications. Send us your operating parameters and water analysis to receive a suitable technical solution and quotation.