Cast Steel Ejector Freshwater Pump

I. Product Overview

Marine cast steel ejector freshwater pumps are core water delivery equipment designed for ship freshwater systems, using ZG270-500 cast steel or ZG310-570 high-strength cast steel as the main material. Based on the ejector pump principle (Venturi effect), they enable efficient transportation and circulation of freshwater. The working principle is that high-pressure water forms a high-speed jet through a cast 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 quenching-tempering treatment and nano-ceramic coating reinforcement, the cast steel material can operate stably in fresh water with a pH of 6-8, with corrosion resistance 3 times higher than ordinary carbon steel. It meets IMO Guidelines for Safe Ship Drinking Water Operations and international classification society certifications (LR, ABS, DNV, etc.), and is widely used in ocean-going cargo ships, luxury cruises, and special vessels.

II. Core Technologies and Material Characteristics

1.Cast Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 20-300m³/h, suitable for ships of 1,000-25,000 tons

Head: 20-50m, self-priming height ≥9m, no priming required at startup

Efficiency index: Ejector efficiency ≥70%, 15%-20% more energy-efficient than traditional centrifugal pumps

Corrosion resistance design: Cast steel surface with nano-ceramic coating (thickness ≥300μm), passing 3,000-hour salt spray test without rust

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 90%, suitable for freshwater 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.

2. Extreme Condition Adaptability

Anti-vibration structure: The integral cast steel housing undergoes dynamic balance treatment, with vibration value ≤2.5mm/s, adapting to the high-frequency vibration environment of ship main engines.

Low-temperature protection design: ZG310-570 cast steel with electric tracing system can transport freshwater at -20℃, preventing pipeline freezing.

3. Long Life and Convenient Maintenance

Wear-resistant reinforcement: Impeller surface treated by laser cladding tungsten carbide (thickness 200μm), 4x improved wear resistance, service life exceeding 25,000 hours.

Modular quick-release structure: Pump body and pipelines use flange quick-connect design, reducing single-component replacement time by 70% and maintenance costs by 40%.

IV. Typical Application Scenarios

1. Ship Domestic Water Systems

Daily water supply: ZG270-500 cast steel pumps provide domestic freshwater for cruise ships, flow 50-100m³/h, meeting drinking water standards with reverse osmosis devices.

Drinking water purification: Linked with UV disinfection equipment, delivering WHO-standard drinking water for ocean-going ships, flow 30-80m³/h.

2. Power System Cooling

Main engine freshwater cooling: ZG310-570 cast steel pumps provide high-pressure freshwater circulation for ocean-going cargo ship main engines, flow 150-250m³/h, controlling cylinder liner temperature at 85-95℃.

Generator heat dissipation: Providing forced cooling for marine auxiliary generators, flow 80-120m³/h, winding temperature ≤110℃.

3. Special-purpose Water Supply

Boiler feed water: High-pressure ejector pumps (head ≥40m) stably supply water for ship boilers, avoiding dry burning risks, flow 20-50m³/h.

LNG ship low-temperature systems: Cast steel pumps transport -30℃ ethylene glycol solution, combined with insulated pipelines to cool LNG pump cabin equipment, flow 40-80m³/h.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Water quality conditions: Choose ZG270-500 for conventional fresh water, ZG310-570 for fresh water with trace corrosive ions

Pressure requirements: Select ZG270-500 for low-pressure systems (≤1.0MPa), ZG310-570 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 60-90m³/h

2. Maintenance Key Points

Daily monitoring: Check inlet/outlet pressure and pipeline tightness daily, ensure 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 nano-ceramic 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 to ensure water quality safety