Marine Cast Iron Cooling Water Pump

I. Product Overview

Marine cast iron cooling water pumps are the "temperature control core" of ship power systems, designed specifically for cooling cycles of diesel engines, generators, boilers, and other equipment. Constructed with high-strength ductile iron (QT400-18) or gray cast iron (HT250), they achieve efficient circulation of fresh water and seawater through the centrifugal pump principle. Their working principle is that an electric motor drives an impeller to rotate, generating centrifugal force to draw cooling medium (fresh water or seawater) from the suction end, pressurize it, and deliver it to the equipment's cooling chamber. After absorbing heat, the medium returns to the cooler or is discharged overboard, enabling continuous temperature reduction. The pump body undergoes integral casting and anti-corrosion coating treatment, with a corrosion-resistant service life of ≥8 years in fresh water and seawater environments. It meets the IMO International Safety Management Code (ISM Code) and classification society certifications (LR, ABS, etc.), and is widely used in merchant ships, engineering vessels, oil tankers, and offshore platforms.

II. Core Technologies and Material Characteristics

1.Cast Iron Material Selection and Performance

2.Key Technical Parameters

Flow range: 20-500m³/h, suitable for ship main engine power 500-20,000kW

Head: 10-50m, meeting the circulation pressure requirements between equipment cooling chambers and coolers

Medium compatibility: Fresh water, seawater (with Cl⁻≤35,000ppm), low-concentration coolants (pH 6-9)

Corrosion resistance design: Seawater cooling models adopt epoxy resin + zinc-rich primer double coating (thickness ≥300μm), passing 1,500-hour salt spray test without rust

Temperature adaptability: Stable operation at -15℃~90℃; high-temperature models can withstand 120℃

III. Technical Advantages and Innovative Design

1. Efficient Heat Dissipation Assurance

Dual-flow impeller design: Adopts a symmetric double volute structure for uniform water distribution, increasing heat exchange efficiency by 15% and stabilizing the temperature difference between equipment inlet and outlet at 8-12℃.

Variable frequency speed regulation technology: Automatically adjusts flow (30%-100% of rated value) according to real-time equipment temperature, achieving an energy-saving rate of 20% and reducing ship power load.

2. Reliability in Extreme Conditions

Anti-cavitation structure: The impeller inlet uses an inducer design, reducing the required net positive suction head (NPSH) by 30% to avoid cavitation damage in low-liquid-level or high-temperature media.

Anti-vibration performance: The pump body and base adopt spring shock absorption devices, with a vibration value ≤2.8mm/s, ensuring stable operation even when the ship heels 25° or trims 10°.

3. Long Service Life and Easy Maintenance

Wear-resistant mechanical seal: Seawater cooling models use silicon carbide-silicon nitride double-end face seals, with a leakage rate ≤3mL/h and a service life exceeding 10,000 hours.

Modular quick-release design: The pump cover and body adopt quick-connect flanges, reducing core component replacement time by 60% and lowering maintenance costs by 40% compared to copper alloy pumps.

IV. Typical Application Scenarios

1. Cooling for Main Engines and Power Equipment

Low-speed diesel engine cooling: 100,000-ton cargo ships are equipped with ductile iron cooling water pumps, with a flow rate of 200-300m³/h and a head of 30m, controlling cylinder liner water temperature at 85±2℃.

Medium-speed diesel engine circulation: Cruise ship auxiliary engines use a dual-pump parallel system, with a single pump flow rate of 80-150m³/h, ensuring stable heat dissipation during continuous generator operation.

2. Boilers and Special Equipment

Ship boiler cooling: Oil tanker steam boilers are equipped with cooling water pumps, with a flow rate of 50-100m³/h and a pressure of 1.2MPa, controlling furnace tube temperature ≤350℃.

Low-temperature equipment on LNG ships: Polar LNG ships use low-temperature resistant cast iron pumps, with a start-up time ≤10 seconds at -10℃, providing cooling seawater for vaporizers.

3. Engineering Vessels and Port Facilities

Power cooling for dredgers: Engineering vessels are equipped with wear-resistant cooling water pumps, capable of passing ≤3mm sediment particles, with a flow rate of 150-250m³/h, adapting to high-sediment water quality in dredging operations.

Heat dissipation for port machinery: crane cooling systems use gray cast iron pumps, with a flow rate of 30-50m³/h, continuously cooling the hydraulic system.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Cooling medium: Choose ductile iron + special coating for seawater cooling; gray cast iron economical type for fresh water cooling

Equipment power: Configure according to the cooling water volume of 10-15L/kW・h for the main engine; for example, a 5,000kW main engine recommends a flow rate of 50-75m³/h

Environmental conditions: Choose enhanced anti-corrosion type for high-salinity sea areas; pump bodies with heating jackets for cold regions

2. Maintenance Key Points

Daily monitoring: Check outlet pressure (fluctuation ≤±0.1MPa), bearing temperature (≤70℃), and sealing status every 300 hours

Regular maintenance: Clean the suction filter (accuracy ≤8mm) monthly; replace lubricating oil (salt spray resistant type for seawater pumps) every six months

In-depth maintenance: Conduct a water pressure test (1.5 times the rated pressure) every 4 years, inspect impeller wear (allowable loss ≤0.5mm), and replace seals

VI. Compliance and Certification

International standards: Complies with IMO ISM Code and ISO 8861 ship cooling system specifications

Classification society certifications: Certified by authoritative institutions such as LR, ABS, and DNV GL

Environmental requirements: Discharge from seawater cooling systems meets MEPC anti-pollution standards, with no excessive heavy metal emissions