Marine Stainless Steel Freshwater Pump

I. Product Overview

Marine stainless steel freshwater pumps are core equipment in ship freshwater supply systems, designed specifically for storing, conveying, and distributing freshwater for domestic use, equipment cooling, and drinking water. Constructed with 316L ultra-low carbon stainless steel (022Cr17Ni12Mo2) or 304 stainless steel (06Cr19Ni10) as the main material, they achieve low-noise, high-precision conveyance of clean freshwater through centrifugal pump principles. Their working principle involves an electric motor driving an impeller to rotate, generating centrifugal force to draw freshwater from storage tanks, pressurize it, and distribute it via pipelines to engine room cooling systems, crew living quarters, kitchens, and drinking water terminals, maintaining water purity throughout (total bacterial count ≤10CFU/mL). The pump body undergoes electrolytic polishing and sterile passivation treatment, with a corrosion-resistant service life of ≥12 years in freshwater and trace mineral environments. It meets IMO International Sanitary Regulations for Ships and freshwater system certification requirements of classification societies such as LR and ABS, widely used in passenger ships, cargo ships, drilling platforms, and all vessels requiring freshwater supply.

II. Core Technologies and Material Characteristics

1.Stainless Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 2-150m³/h, suitable for 50-5000 ship occupants (e.g., 1000-person vessels require flow ≥15m³/h)

Head coverage: 8-40m, meeting pressure requirements for conveyance from freshwater tanks to upper decks (e.g., 15th-floor cabins)

Medium compatibility: Capable of conveying drinking water (meeting WHO standards), domestic water, softened water (hardness ≤50mg/L), and ethylene glycol antifreeze (concentration ≤30%)

Hygienic indicators: Flow-through components comply with FDA 21 CFR 177.2600 food contact standards, with inner wall roughness Ra≤0.4μm and no hygienic dead zones

Temperature adaptability: Operates at 0℃~80℃, capable of conveying hot water (≤60℃) to bathrooms and kitchens

3.Safety and Hygiene Design

Equipped with pressure stabilizing valves, limiting outlet pressure fluctuation to ≤±0.02MPa to prevent pipeline noise or bursting from sudden pressure changes

Inlet fitted with 5μm precision filters to intercept rust and particulate impurities, ensuring terminal water quality meets standards (turbidity ≤1NTU)

III. Technical Advantages and Innovative Design

1. High-Precision Freshwater Conveyance Capacity

Low-pulsation impeller: Adopts closed impeller and double-suction structure, with water flow pulsation ≤5% and operating noise ≤55dB (at 1 meter), 20dB lower than ordinary centrifugal pumps, suitable for quiet cabin environments.

Variable frequency constant pressure control: Links with pressure sensors in the ship’s freshwater main pipeline to automatically adjust rotation speed (800-3000r/min), maintaining stable pressure during water usage fluctuations (e.g., morning/evening peaks) and achieving 12% water savings.

2. Corrosion Resistance and Hygiene Assurance

All-stainless steel flow path: Pump body, impeller, and shaft seal are made of homogeneous stainless steel to prevent metal ion leaching and freshwater contamination (heavy metal content ≤0.01mg/L), meeting drinking water standards.

Self-venting structure: Built-in automatic vent valve in the pump expels air within 30 seconds of startup, avoiding flow attenuation and water oxidation from cavitation (dissolved oxygen fluctuation ≤0.5mg/L).

3. Long-Term Operation and Maintenance Convenience

Maintenance-free shaft seal: Uses a "mechanical seal + food-grade rubber" combination with leakage ≤0.5mL/h and service life exceeding 8000 hours (twice that of traditional seals).

Modular design: Pump cover and body connect via quick-release clips, allowing filter or seal replacement without pipeline disassembly, with maintenance time ≤30 minutes.

IV. Typical Application Scenarios

1. Domestic and Drinking Water Supply

Cruise ship freshwater systems: 3000-passenger cruise ships are equipped with 316L stainless steel freshwater pumps (flow 50-80m³/h, head 35m) to supply 15 cabin decks via looped pipelines. Separate lines for 50℃ bathroom hot water and drinking water maintain stable pressure at 0.6±0.02MPa.

Cargo ship crew water: 200-crew cargo ships use 304 stainless steel freshwater pumps (flow 5-10m³/h, head 20m) to pressurize tank water for kitchen and bathroom supply, 配合紫外线 disinfection to meet IMO drinking water standards.

2. Equipment Cooling and Special Applications

Generator freshwater cooling: 316L stainless steel freshwater pumps (flow 10-30m³/h, pressure 1.0MPa) convey softened water to diesel generator stator cooling systems, controlling inlet-outlet temperature difference at 8±2℃ to ensure generation efficiency.

Polar ship antifreeze supply: In -30℃ environments, pump bodies with electric tracing and insulation heat freshwater to 5℃ for conveyance (flow 8-25m³/h), preventing pipeline freezing and supplying domestic water to researchers.

3. Platform and Engineering Vessel Applications

Drilling platform drinking water: Offshore platforms use 316L stainless steel multi-stage pumps (flow 20-50m³/h, head 40m) operating stably in 95% humidity, with terminal drinking water containing ≤1CFU/mL.

Dredger freshwater systems: Equipped with 304 stainless steel self-priming pumps (flow 10-20m³/h, self-priming height 6m) to draw water from supply ship tanks and pressurize it for crew quarters, adapting to vessel sway (±15° heel).

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Vessel type: 316L stainless steel for ocean-going ships and drinking water systems; 304 stainless steel for inland ships and cooling systems

Water demand: Configure flow at 150L per person per day (including domestic, hygiene, and equipment use); e.g., 500-person vessels require flow ≥75m³/d (3.1m³/h)

Conveyance height: High-head models (30-40m) for upper decks (≥10 floors); standard head (8-20m) for lower structures

2. Maintenance Guidelines

Daily monitoring: Check outlet pressure (fluctuation ≤±0.05MPa), bearing temperature (≤65℃), and filter pressure difference (≤0.1MPa) every 600 hours

Regular maintenance: Clean inlet filters monthly; replace mechanical seals (food-grade fluoroelastomer) annually; test hygiene indicators of flow-through components every 2 years

In-depth maintenance: Conduct pressure tests (1.5× rated pressure) every 5 years; passivate 316L components to ensure hygiene safety

VI. Compliance and Certification

International standards: Complies with ISO 8537 drinking water conveyance equipment standards and IMO Resolution A.1088(28) ship freshwater system regulations

Classification society certifications: Passed type approval for freshwater pumps by LR, ABS, and CCS (including 316L material hygiene testing)

Hygiene certifications: Flow-through components meet NSF/ANSI 61 drinking water safety standards, with no lead or toxin leaching