Cast Iron Ejector Fire Pump

I. Product Overview

Marine cast iron ejector fire pumps are core equipment for ship fire safety systems, using high-strength gray cast iron (HT250) or ductile iron (QT400-18) as the main material. Based on the ejector pump principle (Venturi effect), they enable rapid high-pressure firewater jet and long-distance transportation. The working principle is that high-pressure water forms a high-speed jet through a nozzle, creating vacuum negative pressure in the suction chamber to draw in seawater or freshwater, which is pressurized by a diffuser and then ejected through firewater cannons or sprinkler systems to meet ship fire fighting, deck washing, and emergency cooling needs. After surface treatment with epoxy glass flake coating, the cast iron material can operate stably in seawater with Cl⁻≤20,000ppm, featuring excellent corrosion and impact resistance. It strictly complies with IMO International Code for Fire Safety Systems (FSS Code) and classification society certifications such as CCS, ABS, and DNV, widely used in various ship scenarios including cargo ships, passenger ships, oil tankers, and offshore platforms.

II. Core Technologies and Material Characteristics

1.Cast Iron Material Selection and Performance

2.Key Technical Parameters

Flow range: 50-300m³/h, suitable for ships of 1,000-30,000 tons

Head: 40-120m, meeting the strict requirement of firewater cannon range ≥60m

Self-priming capacity: Self-priming height ≥8m, no priming required, response time ≤30s

Corrosion resistance design: Cast iron surface with epoxy glass flake coating (thickness ≥300μm), passing 3,000-hour salt spray test without rust, seawater erosion resistance increased by 80%

III. Technical Advantages and Innovative Design

1. High-Pressure Jet and Rapid Response

Dual-stage pressurization structure: Adopts series nozzles and diffuser design, instantly increasing water pressure to 1.2-2.0MPa, meeting IMO's mandatory requirement for oil tanker firewater pressure ≥1.2MPa.

Emergency start-up system: Equipped with an independent hydraulic energy storage device, maintaining 30 minutes of continuous jet when the main power fails, ensuring fire safety under extreme conditions.

2. Anti-Clogging and Complex Condition Adaptability

Non-rotating component design: Ejector pumps have no vulnerable parts like impellers or shafts, capable of passing ≤5mm solid particles (such as seaweed, rust), reducing clogging risk by 95% to ensure stable fire system operation in harsh water quality.

Anti-tilt performance: Normal operation under ship trim 22.5° and list 10°, adapting to complex environments like ship swaying .

3. Low Maintenance and Long Life

No-disassembly cleaning: Flow channel with smooth mirror treatment (roughness Ra≤6.3μm), scaling rate 75% lower than traditional pumps, extending maintenance cycle to 24 months.

Modular design: Pump body and pipelines use quick-connect flanges, enabling rapid replacement of core components during maintenance, reducing single maintenance time by 70%.

IV. Typical Application Scenarios

1. Ship Fire Fighting

Oil Tanker Fire Protection: QT400-18 ejector fire pumps provide high-pressure seawater for 300,000 DWT oil tankers, flow 200-300m³/h, combined with fixed foam fire extinguishing systems to effectively extinguish oil fires.

Passenger Ship Emergency: Gray cast iron fire pumps supply freshwater for large cruise ships, flow 100-150m³/h, controlling fire spread through water cannon systems to ensure passenger safe evacuation.

2. Deck Washing and Equipment Cooling

Deck Cleaning: In low-pressure mode (0.6-0.8MPa), ejector pumps quickly wash deck oil and sediment, improving ship daily maintenance efficiency.

Equipment Cooling: Provide emergency cooling for high-temperature main engines and boilers, preventing secondary disasters caused by overheating.

3. Offshore Platform and Port Operations

Platform Fire Protection: High-pressure ejector pumps (head ≥100m) meet fire protection needs of offshore drilling platforms,with water curtain systems to build all-round fire barriers.

Port Rescue: Fire pumps equipped on port tugs can support surrounding ship fires, achieving cross-ship emergency water supply.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Ship type: Choose QT400-18 high-pressure type for oil tankers/LNG ships, HT250 standard type for ordinary cargo ships

Fire protection requirements: According to IMO, each 1,000 GT requires ≥20m³/h flow, recommended to select with 1.5x safety factor

Water quality conditions: Must use ductile iron + epoxy glass flake coating for seawater environments, gray cast iron for freshwater

2. Maintenance Key Points

Daily monitoring: Check inlet/outlet pressure and pipeline tightness daily, ensure pressure fluctuation ≤±10%

Regular maintenance: Clean suction filter (accuracy ≤8mm) quarterly, remove pump cavity scale with 5% dilute hydrochloric acid annually

Anti-corrosion maintenance: Reapply epoxy glass flake paint every two years, inspect zinc sacrificial anode wear and replace timely

VI. Compliance and Certification

International standards: Strictly comply with IMO FSS Code Chapter 5 fire pump technical requirements

Classification society certifications: Passed CCS Rules for the Classification of Steel Ships and ABS Guide for Ship Fire Protection Systems

Performance testing: Each pump passes 1.5x rated pressure test and 2-hour continuous full-load operation test