Marine Stainless Steel Ejector Fresh Water Pump

I. Product Overview

The marine stainless steel ejector fresh water pump is a high-end core equipment of the ship's fresh water supply system. It is specially designed for scenarios with strict requirements on water quality and corrosion resistance, such as ship seawater desalination supply, domestic water supply for high-end ro-ro passenger ships, cooling water circulation for precision equipment, fresh water transfer on offshore engineering platforms, and emergency fresh water guarantee. Its core working principle is to form strong negative pressure suction through the high-speed ejector of the integrated injector to achieve efficient suction and pressure-boosted delivery of fresh water. Relying on the excellent corrosion resistance of stainless steel and the efficient delivery characteristics of the ejector structure, it can stably complete the precise and clean delivery of various fresh water resources, ensuring the reliable realization of key needs such as stable cooling of the ship's power system, high-quality domestic water supply for crew, and emergency fresh water supply.

The core components of the equipment (pump body, injector, impeller, base) are all integrally cast with stainless steel, matched with food-grade temperature-resistant and corrosion-resistant sealing components and reinforced stainless steel transmission shafts. It has core characteristics such as compact structure, super corrosion resistance and salt spray resistance, hygiene without secondary pollution, strong self-priming capacity, and stable and reliable operation, which can easily adapt to complex working conditions such as high humidity, strong salt spray, large temperature difference fluctuations and strict water quality requirements faced by various ocean-going, coastal ships and offshore engineering platforms. As the "core hub" of the ship's high-end fresh water transportation system, the product strictly complies with international and domestic standards such as the International Convention for the Safety of Life at Sea (SOLAS), IMO Marine Machinery Equipment Rules, GB/T 10832-2011 *Marine Pumps*, GB/T 6245-2019 *Fire Pumps*, and GB 4806.9-2016 *National Food Safety Standard for Metal Materials and Products in Contact with Food*. It has obtained certifications from mainstream classification societies such as China Classification Society (CCS), American Bureau of Shipping (ABS), and Lloyd's Register of Shipping (LR), and is widely used in various high-end ships and offshore engineering facilities including 500-200000 ton high-end ocean-going cargo ships, luxury ro-ro passenger ships, LNG carriers, special chemical tankers, offshore drilling platforms and wind power platforms. Compared with cast steel and cast iron fresh water pumps, stainless steel has significant advantages in corrosion resistance, hygiene and safety, service life and adaptability to extreme working conditions. It is especially suitable for medium and high-end ships and offshore engineering with high water quality requirements and harsh navigation environments, and has become the preferred equipment for the fresh water system of high-end ships.

II. Core Technical Parameters

Pressure Range: Rated working pressure 0.3-1.6 MPa, maximum working pressure up to 2.0 MPa, pressure fluctuation error ≤ ±1.0%. It can meet the pressure requirements for long-distance precise transportation of fresh water on ships, stable pressure water supply for multi-layer high-end cabins and pressure-boosted circulation of precision equipment, ensuring stable and controllable water supply pressure.

Flow Range: 5-200 m³/h, which can be customized in grades according to ship tonnage (500-200000 tons) and fresh water demand (number of crew, high-end domestic water standards, equipment cooling demand). The flow stability error under rated working conditions is ≤ ±1.5%, adapting to the fresh water transportation needs of high-end ships of different scales.

Medium Adaptability: Designed specifically for fresh water transportation, it can stably transport ship domestic fresh water, cooling fresh water, fresh water produced by seawater desalination, etc.; suitable for medium viscosity range 1-5 mm²/s, impurity content ≤ 0.05% (particle size ≤ 0.5mm); applicable medium temperature range -10℃ to 85℃, which can cope with navigation in polar low-temperature sea areas and medium-high temperature fresh water transportation working conditions of precision equipment cooling circulation, and can also withstand slightly corrosive fresh water media (such as slightly polluted desalinated water in coastal areas).

Material Parameters: Pump body and injector are made of stainless steel (surface treated with mirror polishing + passivation double protection, roughness Ra ≤ 0.8μm); seals adopt food-grade fluororubber (FKM) + polytetrafluoroethylene (PTFE) composite structure, with excellent temperature-resistant and corrosion-resistant performance, and leakage ≤ 0.005 mL/h, ensuring no leakage and no secondary pollution in fresh water transportation.

Operating Performance: Volumetric efficiency ≥ 92%, total efficiency ≥ 87%; Net Positive Suction Head (NPSH) ≤ 2.8 m, self-priming height ≥ 5.5 m, self-priming time ≤ 25 seconds (at 3m suction lift); operating noise ≤ 68 dB(A), vibration acceleration ≤ 0.8 m/s²; continuous operation life ≥ 15000 hours, supporting 24-hour continuous and stable water supply operations, adapting to the uninterrupted high-quality fresh water demand of high-end ships.

III. Structural Design and Core Advantages

3.1 Core Structural Design

Efficient and Precise ejector Pressure-Boosted Structure: Adopts fluid mechanics optimized integrated injector design, forming uniform strong negative pressure suction through high-speed fluid ejector, greatly improving self-priming efficiency and stability, and can start quickly and smoothly without additional priming water; the ejector channel is precision polished to reduce water flow resistance and eddy current, realizing efficient and low-energy consumption pressure-boosted transportation of fresh water, while avoiding water quality disturbance caused by water flow impact.

Stainless Steel Integral Molding Structure: The pump body and base are formed by integral precision casting process, without splicing welds, with compact and solid structure and tensile strength ≥ 520 MPa, which can withstand the severe bumpy impact during ship navigation and pressure fluctuation during fresh water transportation; stainless steel has excellent thermal conductivity, which can assist in reducing the operating temperature of the pump body, and cooperate with the polished flow channel to reduce scale adhesion and extend the service life of the equipment.

3.2 Core Technical Advantages

Super Corrosion Resistance and Hygiene, Adapting to High-End Needs: Stainless steel has excellent corrosion resistance. After double protection treatment, it can effectively resist the erosion of high salt spray, high humidity and slightly corrosive media on ships, and is not easy to rust or scale; the mirror polished flow channel and food-grade sealing components ensure no secondary pollution in fresh water transportation, meeting the hygiene standards for domestic water supply of high-end ships. Compared with cast steel and cast iron, the service life is extended by more than 80%, suitable for the harsh needs of medium and high-end ships for long-term ocean-going navigation.

Strong Self-Priming Capacity, Stable and Fast Start-Up: The optimized ejector structure enables the self-priming height to reach 5.5 m, far exceeding that of conventional centrifugal pumps and ordinary ejector pumps. No additional priming device is needed, and it can start quickly and smoothly in scenarios such as emergency water supply, water intake in shallow water areas and polar low-temperature start-up, ensuring uninterrupted fresh water supply; the short self-priming time greatly improves emergency response efficiency.

Convenient Maintenance and Low Operation Cost: Key components adopt modular design. Wearing parts such as injectors and seals can be quickly disassembled and replaced with simple tools without overall disassembly of the pump body; stainless steel is not easy to scale or rust. Daily maintenance only needs to regularly check fresh water cleanliness, clean the inlet filter screen and supplement food-grade lubricating oil, with a long maintenance cycle (regular maintenance interval ≥ 12 months), which greatly reduces the maintenance workload and operation cost of the crew.

Safe and Compliant, Wide Adaptability: Strictly complies with international and domestic standards related to ship safety, fresh water transportation and food hygiene, and has passed multiple rigorous tests by classification societies such as pressure test, leakage test, vibration test, salt spray corrosion test and hygiene safety test; adapts to the fresh water systems of various 500-200000 ton high-end ships and offshore engineering, and can be customized according to ship type, fresh water demand and navigation working conditions, with strong adaptability.

IV. Typical Application Scenarios

4.1 High-End Fresh Water Supply for Ship Seawater Desalination System

Seawater desalination is the core way for ocean-going ships to obtain fresh water resources. High-end ships have extremely high requirements for the water quality and supply stability of desalinated water. Relying on the strong self-priming capacity of ≥ 5.5 m, the marine stainless steel ejector fresh water pump can quickly suck the clean fresh water produced by the seawater desalination equipment and accurately transport it to the fresh water storage tank; the food-grade material and sealing design ensure no secondary pollution of desalinated water, meeting high-end domestic water standards; stainless steel has strong corrosion resistance, adapts to the high salt spray environment on the ship deck, and has no rust or scale during long-term operation, ensuring the stable and reliable operation of the supply system.

4.2 Domestic Fresh Water Transportation for High-End Ro-Ro Passenger Ships/Luxury Cruise Ships

Luxury ro-ro passenger ships and cruise ships have strict requirements on the hygiene, stability and quietness of domestic water for crew and passengers. The marine stainless steel ejector fresh water pump has a flow stability error of ≤ ±1.5%, which can accurately control the supply of domestic water and avoid sudden changes in water pressure; food-grade stainless steel and sealing components ensure water quality safety, meeting high-quality water needs such as washing, drinking and kitchen use; the operating noise is ≤ 68 dB(A), which does not affect the quiet environment of the cabin, adapting to the living scenarios of high-end ships.

4.3 Cooling Water Circulation for Ship Precision Equipment

The precision control systems and navigation equipment of LNG carriers and special chemical tankers require clean and stable fresh water circulation cooling, which has extremely high requirements for the transportation precision and corrosion resistance of the pump. The rated working pressure of the marine stainless steel ejector fresh water pump is stable, which can accurately match the pressure demand of the cooling system of precision equipment and ensure the smooth circulation of cooling water; stainless steel is corrosion-resistant and not easy to scale, which can avoid impurities blocking the cooling pipeline and protect the safe operation of precision equipment; low vibration operation does not affect the working stability of precision equipment.

4.4 Fresh Water Supply for Offshore Engineering Platforms

Offshore engineering facilities such as offshore drilling platforms and wind power platforms are scarce in fresh water resources and have harsh navigation environments (high salt spray, strong wind and waves), which have extremely high requirements for the corrosion resistance and reliability of water supply equipment. The marine stainless steel ejector fresh water pump can adapt to the extremely harsh environment of the platform and stably complete the transfer and supply of fresh water; the continuous operation life is ≥ 15000 hours, supporting 24-hour uninterrupted water supply, meeting the high-quality domestic water needs of platform operators and the fresh water needs of equipment operation; it has strong corrosion resistance, can withstand the high salt spray erosion of the platform for a long time, and reduce equipment failures.

4.5 Emergency Fresh Water Guarantee for Ships Sailing in Polar/Low-Temperature Sea Areas

Ships sailing in polar and low-temperature sea areas face extremely low temperature environments, which have strict requirements on the low-temperature start-up performance and reliability of fresh water pumps. The marine stainless steel ejector fresh water pump has an applicable medium temperature range as low as -10℃, which can start quickly and smoothly in low-temperature environments without additional preheating; the strong self-priming capacity can quickly respond to emergency water supply needs and ensure the emergency fresh water supply for the crew; the mechanical properties of stainless steel are stable in low-temperature environments, with no risk of brittle fracture, adapting to polar navigation working conditions.