Stainless Steel Ejector Freshwater Pump

I. Product Overview

Marine stainless steel ejector freshwater pumps are high-efficiency water delivery equipment designed for ship freshwater systems, using 316L austenitic stainless steel or duplex stainless steel 2205 as the main material. Based on the ejector pump principle (Venturi effect), they enable forced circulation and long-distance transportation of freshwater. The working principle is that high-pressure water forms a high-speed jet through a stainless steel nozzle, creating vacuum negative pressure in the suction chamber to draw in freshwater, which is then pressurized by a diffuser and delivered to the ship's domestic water, main engine cooling, and boiler feed water systems. After solution treatment and electropolishing reinforcement, the stainless steel has 70% better corrosion resistance than cast steel, operating stably in fresh water with a pH of 6-8. It meets IMO Guidelines for Safe Ship Drinking Water Operations and international classification society certifications (LR, ABS, DNV, etc.), widely used in ocean-going cargo ships, luxury cruises, and special vessels.

II. Core Technologies and Material Characteristics

1.Stainless Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 20-400m³/h, suitable for ships of 1,000-30,000 tons

Head: 25-60m, self-priming height ≥10m, no priming required at startup

Efficiency index: Ejector efficiency ≥75%, 20%-25% more energy-efficient than traditional centrifugal pumps

Corrosion resistance design: Electropolished surface (Ra≤0.6μm), passing 5,000-hour salt spray test without rust, 80% improved fresh water erosion resistance

III. Technical Advantages and Innovative Design

1. Efficient Water Transportation and Anti-Clogging Capability

Non-rotating component design: Ejector pumps have no vulnerable parts such as impellers or shafts, capable of passing ≤3mm solid particles, reducing clogging risk by 95%, suitable for fresh water environments with trace sediment.

Constant pressure water supply technology: Dual-nozzle linkage design automatically adjusts flow, maintaining pressure fluctuation ≤±5% under 15° ship tilt conditions to ensure stable water supply.

2. Extreme Condition Adaptability

Anti-vibration structure: The integral stainless steel housing undergoes dynamic balance treatment, with vibration value ≤2.0mm/s, adapting to the high-frequency vibration environment of ship main engines and reducing pipeline fatigue risks.

Low-temperature protection design: Duplex stainless steel 2205 with electric tracing system can transport fresh water at -30℃, preventing pipeline freezing, suitable for polar vessels.

3. Long Life and Convenient Maintenance

Wear-resistant reinforcement: Impeller surface treated by laser cladding tungsten carbide (thickness 200μm), 5x improved wear resistance, service life exceeding 40,000 hours.

Modular quick-release structure: Pump body and pipelines use clamp-type quick-connect design, reducing single-component replacement time by 80% and life-cycle maintenance costs by 45%.

IV. Typical Application Scenarios

1. Ship Domestic Water Systems

Daily water supply: 316L stainless steel pumps provide domestic fresh water for cruise ships, flow 60-120m³/h, meeting drinking water standards with reverse osmosis devices to ensure water demand for thousands of passengers.

Drinking water purification: Linked with UV disinfection equipment, delivering WHO-standard drinking water for ocean-going ships, flow 30-80m³/h, adapted to multi-deck cabin negative pressure drainage.

2. Power System Cooling

Main engine freshwater cooling: Duplex stainless steel 2205 pumps provide high-pressure freshwater circulation for ocean-going cargo ship main engines, flow 180-300m³/h, combined with plate heat exchangers to control cylinder liner temperature at 85-95℃.

Generator heat dissipation: Providing forced cooling for marine auxiliary generators, flow 80-150m³/h, controlling winding temperature ≤110℃ to avoid overheating failures.

3. Special-purpose Water Supply

Boiler feed water: High-pressure ejector pumps (head ≥50m) stably supply water for ship boilers, avoiding dry burning risks, flow 20-60m³/h, adapted to steam-powered ships.

LNG ship low-temperature systems: Stainless steel pumps transport -30℃ ethylene glycol solution, combined with insulated pipelines to cool LNG pump cabin equipment, flow 50-100m³/h, ensuring safe operation of low-temperature equipment.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Water quality conditions: Choose 316L stainless steel for conventional fresh water, duplex steel 2205 for fresh water with trace corrosive ions

Pressure requirements: Select 316L for low-pressure systems (≤1.0MPa), duplex steel 2205 for high-pressure systems (>1.0MPa)

Flow matching: Configure at 1.5 times the actual water consumption, e.g., 1,000-passenger ships recommend flow 70-100m³/h

2. Maintenance Key Points

Daily monitoring: Real-time monitoring of inlet/outlet pressure and pipeline tightness, ensuring pressure fluctuation ≤±8%

Regular maintenance: Clean suction filters (accuracy ≤5mm) quarterly, remove pump cavity scale with citric acid solution annually

In-depth maintenance: Magnetic particle inspection every 2 years, reapply passivation coating, and replace seals

VI. Compliance and Certification

International standards: Complies with IMO Guidelines for Safe Ship Drinking Water Operations and ISO 8680 ship water supply system specifications

Classification society certifications: Passed LR Rules for the Classification of Ships and ABS Rules for Building and Classing Ships

Hygiene standards: Components in contact with fresh water comply with NSF 61 certification; stainless steel is 100% recyclable