Marine Copper Freshwater Pump

I. Product Overview

Marine copper freshwater pumps are core equipment in ship freshwater supply systems, designed specifically to transport clean or low-impurity freshwater such as drinking water, washing water, cooling system freshwater, and boiler feed water. They ensure freshwater supply for ship personnel and cooling needs of equipment. Constructed with tin bronze (ZCuSn10Pb1) or naval brass (HAl60-1-1) as the main material, they achieve efficient freshwater delivery through centrifugal or vortex pump principles. A power source (electric motor or main engine transmission) drives the impeller to rotate, generating centrifugal force to draw freshwater from storage tanks, pressurize it, and deliver it to water points or cooling equipment via pipelines. The pump body undergoes precision machining and anti-oxidation treatment, with a corrosion-resistant service life of ≥10 years in ambient temperature freshwater and short-term high-temperature (≤80℃) environments. It meets IMO Ship Freshwater System Safety Specifications and freshwater equipment certification requirements of classification societies such as LR and ABS, widely used in freshwater supply and cooling systems of passenger ships, cargo ships, fishing boats, and other vessels.

II. Core Technologies and Material Characteristics

1.Copper Material Selection and Performance

2.Key Technical Parameters

Flow range: 2-100m³/h, suitable for 50-5000 ship occupants (e.g., 1000-passenger ships require domestic water flow ≥15m³/h)

Pressure control: Outlet pressure 0.6-3.0MPa, pressure stability ≤±0.03MPa, ensuring balanced water pressure at use points (e.g., shower faucet outlet pressure 0.2-0.4MPa)

Medium compatibility: Capable of conveying drinking water (meeting WHO water quality standards), cooling freshwater (with corrosion inhibitors), softened water (hardness ≤50mg/L as CaCO₃), and clean liquids with temperature ≤80℃

Suction performance: Suction lift ≥6m, net positive suction head (NPSH) ≤3m, suitable for water absorption from low-level storage tanks without additional priming devices

Operation efficiency: Hydraulic efficiency ≥85% (under design conditions), 8% higher than cast iron pumps of the same specification, saving up to 5000kWh/year per unit

3.Safety and Sanitary Design

Surface roughness of flow-through components ≤Ra0.8μm, meeting FDA food contact material standards to prevent bacterial growth (colony count ≤10CFU/mL)

Equipped with pressure protection valves that automatically relieve pressure when outlet pressure exceeds 1.2 times the rated value, preventing pipeline bursting (e.g., domestic water pipes have pressure resistance ≤1.0MPa)

Low-noise structure: Impellers adopt low-noise hydraulic design, with operating noise ≤65dB (measured at 1 meter), meeting passenger cabin noise requirements

III. Technical Advantages and Innovative Design

1. Efficient Water Delivery Capacity

Low cavitation impeller: Uses double-suction impellers and streamlined blade design to reduce cavitation margin from 5m to 3m, enabling cavitation-free operation in low-level storage tanks (liquid level difference 6m) and extending pump life by 30%.

Wide operating condition adaptability: Flow can stably operate in the 30%-110% rated range. For example, during low water usage periods at night on passenger ships (flow reduced to 50%), efficiency remains ≥80%, avoiding losses from frequent start-stop cycles.

2. Corrosion Resistance and Sanitary Guarantee

All-copper flow system: Pump body, impeller, and seals are made of copper-based materials, avoiding rust contamination from cast iron pumps and ensuring drinking water quality (iron content ≤0.3mg/L).

Sterile flow channel design: Flow channels have no dead corners and smooth transitions, allowing CIP in-situ cleaning (80℃ hot water + citric acid) to completely remove biofilms, meeting IMO ship drinking water hygiene requirements.

3. Adaptation to Ship Freshwater Characteristics

Dual-mode operation: Supports constant-pressure water supply (domestic water systems) and variable-flow cooling (equipment cooling systems), with frequency conversion control for dynamic flow adjustment, achieving 15% energy savings.

Tilt resistance: Operates normally under ship heel ±20° and trim ±10° conditions, with flow fluctuation ≤5%, ensuring uninterrupted cooling systems in severe sea conditions.

IV. Typical Application Scenarios

1. Domestic Water Supply

Passenger ship centralized water supply: 3000-passenger ships are equipped with naval brass freshwater pump sets (3 units in parallel, single unit flow 20m³/h) with pressure 1.0MPa. They deliver freshwater to guest rooms, restaurants, and other water points through pipelines, with constant pressure control ensuring stable shower water temperature (±2℃).

Fishing boat domestic water: Tin bronze freshwater pumps (flow 3-5m³/h) draw freshwater from storage tanks to kitchens and bathrooms, resisting corrosion from occasional seawater mixing (salinity ≤5‰) and extending maintenance intervals to 6 months.

2. Equipment Cooling Systems

Main engine cooling water supply: 15,000kW main engines are equipped with tin bronze freshwater pumps (flow 50-80m³/h, pressure 2.5MPa) to deliver cooling freshwater to cylinder liners and piston cooling chambers, controlling inlet water temperature at 30-40℃ and outlet temperature difference ≤10℃.

Generator cooling: 1000kW diesel generators use naval brass pumps (flow 5-10m³/h, pressure 1.2MPa) to provide circulating cooling water to generator cylinders, cooperating with thermostatic valves to stabilize outlet temperature at 65±3℃.

3. Special Freshwater Transportation

Boiler feed water: Ship steam boilers use high-pressure tin bronze pumps (flow 2-5m³/h, pressure 3.0MPa) to deliver softened water to boiler drums, with water quality meeting standards (total dissolved solids ≤300mg/L) to avoid scaling and blockage.

Polar ship anti-freezing: Tin bronze pumps with insulation layers in -20℃ environments transport antifreeze containing ethylene glycol (30% concentration) with flow 10-20m³/h, preventing pipeline freezing and ensuring unobstructed cooling systems during low-temperature main engine startup.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Application scenarios: Tin bronze pumps for high-temperature cooling and high-pressure feed water; naval brass pumps for domestic water and ambient temperature transportation

Flow calculation: Domestic water is configured at 200L per person per day (including 50L drinking water and 150L washing water). For example, 500-person ships require flow ≥12.5m³/h

Pressure requirements: High-pressure models (1.6-3.0MPa) for cooling systems (main engines, generators); low-pressure models (0.6-1.0MPa) for domestic water

2. Maintenance Points

Daily monitoring: Check outlet pressure (fluctuation ≤±0.05MPa), bearing temperature (≤65℃), and seal leakage (≤1mL/h) every 800 hours

Regular maintenance: Replace mechanical seals (food-grade nitrile rubber) every 2000 hours; clean inlet filters (preventing algae blockage); inspect impeller wear (allowable radial clearance ≤0.2mm)

Sanitary maintenance: Circulate and disinfect domestic water pumps with sodium hypochlorite solution (50ppm concentration) for 30 minutes every 3 months to ensure water colony count ≤10CFU/mL

VI. Compliance and Certification

International standards: Complies with ISO 9001 quality management system and IMO MSC.1/Circ.1580 freshwater system guidelines

Classification society certifications: Passed type approval for freshwater pumps by LR, ABS, and CCS (including 500-hour drinking water operation tests)

Sanitary certifications: Flow-through components meet FDA 21 CFR 175.300 food contact material standards and NSF/ANSI 61 drinking water system certification