Cast Steel Ejector Bilge Pump

I. Product Overview

Marine cast steel ejector bilge pumps are core equipment designed for efficient bilge water discharge, using ZG270-500 cast steel or ZG310-570 high-strength cast steel as the main material. Based on the ejector pump principle (Venturi effect), they enable rapid pumping of bilge water (mixed media with oil, sediment, rust, etc.). The working principle is that high-pressure water forms a high-speed jet through a cast steel nozzle, creating vacuum negative pressure in the suction chamber to draw in bilge water, which is then discharged through a diffuser. After quenching-tempering treatment and nano-ceramic coating reinforcement, the cast steel material features excellent impact resistance and abrasion-corrosion resistance, operating stably in seawater with Cl⁻≤25,000ppm and complex bilge environments. It meets IMO MARPOL Annex I anti-pollution conventions and international classification society certifications (LR, ABS, DNV, etc.), widely used in bilge drainage for cargo ships, passenger ships, and special vessels.

II. Core Technologies and Material Characteristics

1.Cast Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 30-300m³/h, suitable for ships of 1,000-20,000 tons

Head: 15-40m, self-priming height ≥8m, no priming required

Impurity passing capacity: Passes ≤8mm solid particles, clogging risk reduced by 95%

Structural strength: Cast steel components tested by magnetic particle inspection (MT), bearing 4x rated pressure

Corrosion resistance design: Nano-ceramic coating (thickness ≥300μm), 5,000-hour salt spray test without rust, 80% improved erosion resistance

III. Technical Advantages and Innovative Design

1. Efficient Drainage and Anti-Clogging Capability

Non-rotating component design: No vulnerable parts like impellers or shafts. Large-diameter flow channel design ensures smooth transport of solid particles and fibrous impurities in bilge water, ideal for harsh conditions with complex impurities.

Dynamic self-cleaning function: Spiral guide grooves on the diffuser inner wall automatically remove attached dirt by water flow scouring, extending maintenance cycles to 18 months.

2. Extreme Condition Adaptability

Anti-tilt performance: Stable drainage under ship trim 22.5° and list 15°, ensuring timely bilge water discharge in emergencies.

Explosion-proof safety design: Cast steel generates no sparks during friction. Combined with explosion-proof motors (Ex d IIB T4), it is suitable for hazardous bilges with combustible gases (e.g., oil tanker cargo bilges).

3. Long Life and Convenient Maintenance

Wear-resistant reinforcement: Cast steel impeller surface treated by laser cladding tungsten carbide, 4x improved wear resistance, service life exceeding 25,000 hours.

Quick-release modular structure: Pump body and pipelines use quick-connect flanges, reducing single-component replacement time by 80% and significantly lowering ship downtime maintenance costs.

IV. Typical Application Scenarios

1. Merchant Ship Bilge Drainage

Cargo ship engine room bilge: ZG270-500 cast steel ejector pumps drain engine room water with lubricating oil, flow 80-150m³/h, combined with oil-water separators for compliant discharge (oil content ≤15ppm).

Passenger ship sanitary bilge: Provides negative pressure drainage for multi-deck cabins, self-priming height 9m, ensuring rapid discharge of domestic sewage and avoiding odor accumulation.

2. Special Vessel Emergency Drainage

Offshore engineering vessels: ZG310-570 cast steel ejector pumps drain at ≥200m³/h under drilling platform tilt conditions, meeting SOLAS emergency requirements.

Fireboat bilge: High-temperature resistance design (temperature ≤90℃), draining high-temperature bilge water after fire fighting, with fire protection systems to ensure ship safety.

3. Oil Tankers and Hazardous Cargo Vessels

Oil tanker cargo bilge: Anti-static cast steel ejector pumps (grounding resistance ≤4Ω) drain bilge water with crude oil residues, avoiding explosion risks from sparks.

Chemical tanker bilge: Nano-ceramic coating effectively resists corrosion from chemicals like methanol and styrene, ensuring safe drainage system operation.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Water quality conditions: Choose ZG270-500 for conventional bilge water, ZG310-570 for particulate/high-salt/corrosive media

Ship conditions: Ocean-going vessels and special operation ships require ZG310-570 (superior anti-tilt performance)

Flow matching: Configure at 1.8x maximum bilge water generation, e.g., 5,000-ton cargo ships recommend flow 120-180m³/h

2. Maintenance Key Points

Daily monitoring: Real-time monitoring of inlet/outlet pressure and vacuum, ensuring pressure fluctuation ≤±10%

Regular maintenance: Clean suction grilles (filtration accuracy ≤12mm) quarterly, remove pump cavity dirt with special cleaners annually

In-depth maintenance: Nondestructive testing every 3 years, reapply nano-ceramic coating, and inspect seal status

VI. Compliance and Certification

International standards: Complies with IMO MARPOL Annex I Regulation 15 for bilge water discharge

Classification society certifications: Passed LR Rules for the Classification of Ships and ABS Rules for Building and Classing Ships

Safety specifications: Obtained ATEX explosion-proof certification, meeting hazardous environment standards