Marine Cast Iron General Pump

I. Product Overview

Marine cast iron General pumps are versatile equipment in ship fluid conveying systems, constructed with high-strength ductile iron (QT400-18) or gray cast iron (HT250) as the main materials. They realize the general conveying of various media such as fresh water, seawater, and low-viscosity oils based on the core principle of centrifugal pumps. Their working principle is that an electric motor drives an impeller to rotate and generate centrifugal force, which draws the medium from the suction end, pressurizes it, and conveys it to the target area through the discharge pipeline. They can flexibly adapt to diverse scenarios such as ship ballasting, cooling, and cleaning. The pump body undergoes integral casting and anti-corrosion coating treatment, with a corrosion-resistant service life of ≥8 years in fresh water, seawater, and slightly corrosive media. It meets the IMO International Safety Management Code (ISM Code) and classification society certifications (LR, ABS, etc.), and is widely used in inland vessels, coastal cargo ships, engineering ships, and port auxiliary facilities.

II. Core Technologies and Material Characteristics

1.Cast Iron Material Selection and Performance

2.Key Technical Parameters

Flow range: 10-300m³/h, suitable for 300-30,000-ton vessels

Head: 8-60m, meeting the conveying height and distance requirements of different media

Medium compatibility: Capable of conveying fresh water, seawater, diesel oil (viscosity ≤100cSt), and low-concentration chemicals (pH 6-9)

Corrosion resistance design: Epoxy resin coating thickness ≥200μm, 1,200-hour salt spray test passed without rust

Temperature adaptability: Stable operation at -15℃~80℃

III. Technical Advantages and Innovative Design

1. Multi-Scenario General Capability

Modular impeller design: By replacing impellers of different materials (cast iron/bronze), the medium type can be quickly switched to meet the conveying needs of fresh water, seawater, light oil, etc., with a conversion time ≤30 minutes.

Wide head adjustment: Adopting frequency conversion speed regulation and impeller cutting technology, the head can be adjusted within 60%-120% of the rated value, adapting to different working conditions such as ballasting and cooling.

2. High-Reliability Structure

Axial force balancing device: Double-suction impeller or balance drum design reduces axial force by 60%, with a vibration value ≤3.5mm/s, ensuring 6,000 hours of continuous trouble-free operation.

Anti-leakage seal: The mechanical seal adopts a silicon carbide-graphite combination, with a leakage rate ≤3mL/h, maintaining good sealing performance in media with a sand content ≤500ppm.

3. Low Maintenance and Economy

Wear-resistant and corrosion-resistant process: The flow-through components undergo phosphating + painting double treatment, with wear resistance 2 times higher than that of ordinary cast iron, and a service life exceeding 30,000 hours.

General spare parts design: Core components such as bearings and seals adopt standardized specifications, reducing procurement costs by 40%, and are common with the same series of pump models, reducing spare parts inventory.

IV. Typical Application Scenarios

1. Basic Ship Conveying

Ballast water adjustment: Equipping 10,000-ton cargo ships with ductile iron General pumps, with a flow rate of 80-150m³/h, to quickly complete the filling and draining of ballast tanks and adjust ship stability.

Fresh water/seawater replenishment: Inland cruise ships use gray cast iron pumps, with a flow rate of 30-60m³/h, to simultaneously meet the needs of domestic fresh water conveying and deck flushing seawater supply.

2. Power System Assistance

Main engine cooling water replenishment: General pumps on coastal cargo ships replenish water for diesel engine cooling systems, with a flow rate of 50-100m³/h, and control the water temperature ≤75℃ in conjunction with heat exchangers.

Fuel bunkering: Port tugs transfer diesel oil between tanks through General pumps, with a flow rate of 20-50m³/h, meeting the needs of ship refueling and emergency fuel supply.

3. Engineering and Special Operations

Engineering ship cleaning: Dredgers are equipped with high-pressure General pumps, with a head of 50m and a flow rate of 100-200m³/h, for flushing sediment from dredging equipment.

Emergency drainage: In emergency situations such as ship bilge flooding, General pumps can be used as backup drainage equipment, with a single pump flow rate of 100m³/h, cooperating with emergency systems for rapid drainage.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Medium type: Choose ductile iron + anti-corrosion coating for seawater/sediment-containing water, and gray cast iron economical type for fresh water/light oil

Flow and head: Configure according to 1.1 times the maximum demand; for example, the ballast system of a 5,000-ton cargo ship recommends a flow rate of 60-100m³/h and a head of 20-30m

Environmental conditions: Choose enhanced anti-corrosion type for high-salinity sea areas, and configure electric tracing devices for cold regions

2. Maintenance Key Points

Daily monitoring: Check bearing temperature (≤75℃) and outlet pressure (fluctuation ≤±0.2MPa) every 500 hours

Regular maintenance: Clean the suction filter (accuracy ≤8mm) every quarter, and replace lubricating oil (ISO VG32) every six months

In-depth maintenance: Disassemble and inspect impeller wear (allowable loss ≤1mm) every 4 years, replace seals, and re-spray anti-corrosion coating

VI. Compliance and Certification

International standards: Complies with IMO ISM Code and ISO 9906 general technical specifications for pumps

Classification society certifications: Certified by LR, ABS, CCS, and other institutions

Environmental requirements: Meets MEPC.279(70) anti-pollution standards, with 100% recyclable materials