Marine Cast Steel Ballast Water Pump

I. Product Overview

Marine cast steel ballast water pumps are core equipment for ship stability adjustment, designed specifically for ballast water injection, discharge, and inter-tank transfer. Constructed with high-strength carbon cast steel (WCB) or alloy cast steel (WC6), they achieve large-flow seawater transportation through centrifugal or axial flow pump principles. Their working principle involves a power source (electric motor or diesel engine) driving an impeller to rotate, generating centrifugal force to draw in and pressurize seawater from overboard, which is then delivered to ballast tanks via pipelines, or conversely, discharge water from tanks overboard. This adjusts the ship's draft, trim, and heel. The pump body undergoes integral forging and anti-marine corrosion treatment, with a corrosion-resistant service life of ≥12 years in high-salinity seawater environments. It meets the IMO International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) and certification requirements of classification societies such as LR and ABS, widely used in ocean-going cargo ships, oil tankers, LNG carriers, and large engineering vessels.

II. Core Technologies and Material Characteristics

1.Cast Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 100-1500m³/h, suitable for 5,000-300,000-ton vessels

Head: 15-60m, meeting requirements for rapid ballast tank filling/draining and long-distance transportation

Medium adaptability: Capable of transporting seawater and brackish water with sediment content ≤1000ppm, temperature resistance -5℃~45℃

Corrosion resistance design: Internal and external surfaces arc-sprayed aluminum + sealing coating (thickness ≥300μm), 2500-hour salt spray test without rust

Cavitation performance: Net positive suction head (NPSH) ≤3.5m, avoiding cavitation damage under low liquid level conditions

3.Energy-Saving Characteristics

Wide high-efficiency range (70%-110% of rated flow), operating efficiency ≥82%, 15% more energy-efficient than ordinary cast iron pumps

Supports frequency conversion speed regulation, flow adjustment range 30%-100%, adapting to flow requirements of different ballast stages

III. Technical Advantages and Innovative Design

1. Large-Flow Efficient Transportation

Double-suction impeller structure: Symmetrically arranged double-suction impeller, automatic axial force balance, 50% higher flow than single-suction pumps, vibration value ≤2.5mm/s, extending pipeline life.

Guide vane type pressure chamber: Optimized through CFD flow field simulation, water flow loss reduced by 20%, maintaining efficiency above 85% at 1000m³/h flow.

2. Marine Environment Adaptability

Sediment wear resistance design: Impeller high-chromium cast iron (Cr28) overlay wear-resistant layer, flow components hardness up to HRC60, 3 times more wear-resistant than ordinary cast steel.

Anti-marine biofouling: Inner wall coated with low surface energy coating (surface tension ≤30mN/m), reducing shellfish and algae adhesion, maintenance cycle extended to 12 months.

3. Intelligent Control and Safety Assurance

Intelligent ballast linkage: Integrated PLC control system, capable of linking with ship ballast management system (BMS), automatically completing the entire "injection-discharge-adjustment" process with response time ≤2 seconds.

Multiple protection functions: Equipped with overload, overpressure, and dry operation protection, automatically shutting down when sediment content exceeds standard (≥1500ppm) to avoid pump body wear.

IV. Typical Application Scenarios

1. Ballast Adjustment for Large Merchant Ships

300,000-ton VLCC: Equipped with 3 alloy cast steel ballast water pumps (single pump flow 1200m³/h), operating in parallel to achieve 15,000 tons of water discharge per hour, meeting rapid ballast adjustment needs.

100,000-ton container ship: Adopts double-suction ballast pump with flow 800m³/h, cooperating with frequency conversion system to adjust draft during port stay, ensuring container loading and unloading efficiency.

2. Special Applications for Special Vessels

LNG carrier cargo tank ballast: WC6 alloy cast steel pump body adapted to -163℃ low-temperature environment, through inert gas sealing design, avoiding icing caused by contact between seawater and low-temperature pipelines.

Engineering ship dynamic ballast: Dredgers equipped with wear-resistant ballast water pumps, capable of transporting seawater with sediment content 1500ppm, flow 500m³/h, cooperating with positioning system to adjust ship balance in real-time.

3. Ports and Auxiliary Facilities

Floating dock ballast system: Uses large-diameter cast steel ballast pumps (DN600), flow 1500m³/h, completing floating dock lifting adjustment within 3 hours.

Offshore platform ballast: Ballast water pumps of offshore wind power installation platforms have self-priming capacity (self-priming height 6m), adapting to liquid level changes during platform lifting.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Ship tonnage: 5,000-50,000 tons select single pump system (flow 100-500m³/h), over 50,000 tons select dual pump parallel system (total flow ≥1000m³/h)

Sea area conditions: High sediment sea areas (such as the Yellow River Estuary) select WC6 alloy cast steel + wear-resistant coating, deep-sea navigation select WCB economical type

Ballast efficiency: Configure according to "full tank filling/draining time ≤6 hours", for example, 50,000m³ ballast tank recommends total flow ≥8000m³/h

2. Maintenance Points

Daily monitoring: Check bearing temperature (≤75℃), inlet and outlet pressure difference (≤0.1MPa), and impeller vibration (≤3.0mm/s) every 800 hours

Regular maintenance: Clean the suction filter (precision ≤10mm) every six months, replace mechanical seal (using silicon carbide-graphite material) every year

In-depth maintenance: Conduct water pressure test (1.5 times the rated pressure) every 5 years, inspect impeller wear (allowable deviation ≤1mm), and re-spray anti-corrosion coating

VI. Compliance and Certification

International standards: Complies with IMO BWM Convention Annex A and MEPC.280(70) ballast water management system specifications

Classification society certification: Passed type approval for ballast pumps by LR, ABS, CCS and other institutions (including material, performance, and safety tests)

Environmental requirements: Pump body materials 100% recyclable, coatings free of heavy metals, meeting IMO anti-pollution requirements