Marine Gear Fuel Pump

I. Product Overview

Marine gear fuel pumps are the "power core" of ship fuel supply systems, designed specifically to deliver fuel (such as diesel, heavy oil, and residual oil) to power equipment like diesel engines and gas turbines. They ensure full fuel atomization and efficient combustion through stable pressurization. Constructed with cast iron (HT300), bronze alloy (ZCuAl9Fe4Ni4), or stainless steel (316L) as the main material, they utilize volumetric changes from the rotation of a pair of high-precision meshing gears to draw fuel from fuel tanks, pressurize it, and deliver it to injectors or burners after filtration. The pump body undergoes anti-corrosion treatment and precision machining, with a service life of ≥8 years in -20℃~150℃ environments. It meets IMO Ship Fuel System Safety Specifications (MSC.285(86)) and fuel pump certification requirements of classification societies such as RS, LR, ABS, and CCS, widely used in fuel supply systems of oil tankers, cargo ships, passenger ships, and other vessel types.

II. Core Technologies and Material Characteristics

1.Material Selection and Performance

2.Key Technical Parameters

Flow range: 1-100m³/h, suitable for equipment power 1000-50,000kW (e.g., 20,000kW main engines require flow ≥20m³/h)

Pressure coverage: 0.8-5.0MPa, meeting pressure requirements for transportation from fuel tanks to injectors (including pipeline resistance and filter pressure drop)

Medium compatibility: Capable of conveying light diesel (viscosity 8-20cSt), heavy diesel (viscosity 20-100cSt), heavy oil (viscosity 100-500cSt, requiring heating), and fuel with temperature -20℃~150℃

Self-priming performance: Self-priming height ≥3m, priming time ≤40 seconds, suitable for oil suction from low-level fuel tanks without manual oil filling

Volumetric efficiency: ≥96% under design conditions, 4% higher than vane pumps of the same specification; maintains ≥88% efficiency in high-viscosity heavy oil

3.Safety and Explosion-Proof Design

Explosion-proof certification: Motors adopt Ex d IIB T4 Gb explosion-proof grade, suitable for Zone 1 hazardous areas near fuel tanks to prevent safety risks from oil and gas leakage

Overpressure protection: Safety valves automatically relieve pressure (returning oil to fuel tanks) when outlet pressure exceeds 1.2 times the rated value, avoiding pipeline burst

Impurity interception: Inlet fitted with 20μm precision filters, cooperating with optimized gear side clearance (≤0.03mm) to prevent particle scratches on meshing surfaces

III. Technical Advantages and Innovative Design

1. High-Viscosity Fuel Conveying Capacity

Helical gear meshing structure: Uses 30° helix angle helical gears, meshing more smoothly than spur gears. In heavy oil with 500cSt viscosity, pressure fluctuation ≤±0.1MPa, with noise 10dB lower than spur gear pumps.

Integrated heating system: Pump bodies are wrapped with heating jackets (2-5kW power), capable of heating heavy oil from ambient temperature (500cSt viscosity) to 80℃ (viscosity reduced to 80cSt), ensuring fuel fluidity in low-temperature environments.

2. Corrosion and Wear Resistance Enhancement

Bronze gear surface hardening: Bronze alloy gears undergo nitriding treatment, achieving surface hardness HV500, improving resistance to sulfur corrosion in fuel by 40%, and extending service life to 12,000 hours.

Stainless steel flow channel polishing: 316L flow components undergo mirror polishing (Ra≤0.8μm), reducing heavy oil colloid adhesion, extending cleaning intervals to 300 hours, and reducing maintenance frequency by 50% compared to ordinary pumps.

3. Adaptability to Ship Operating Conditions

Vibration-resistant design: Pump units and bases adopt spring shock absorbers + rubber pad composite damping, with vibration values ≤2.8mm/s, ensuring stable operation in high-vibration main engine room environments.

Wide temperature range operation: Capable of conveying diesel with anti-freeze additives (20cSt viscosity) in -20℃ low-temperature environments and preheated heavy oil in 150℃ high-temperature environments, with flow attenuation ≤5%.

IV. Typical Application Scenarios

1. Main Engine Fuel Supply

Low-speed diesel engine fuel supply: 30,000kW low-speed main engines are equipped with stainless steel gear fuel pumps (flow 30-50m³/h, pressure 3.0MPa) to deliver heavy oil heated to 120℃ (150cSt viscosity) to injectors, maintaining stable fuel supply pressure at 2.5±0.1MPa and ensuring atomized particle diameter ≤50μm.

Medium-speed diesel engine fuel supply: 10,000kW medium-speed main engines use bronze alloy gear pumps (flow 15-20m³/h, pressure 2.5MPa) to deliver heavy diesel (50cSt viscosity) to high-pressure fuel pumps, cooperating with flow regulators to achieve precise fuel supply (±2% error) during main engine load changes.

2. Auxiliary Engine and Emergency Fuel Supply

Diesel generator fuel supply: 2000kW diesel generators are equipped with cast iron gear pumps (flow 2-5m³/h, pressure 1.0MPa) to draw light diesel from daily fuel tanks, ensuring continuous fuel supply without pressure fluctuation during generator operation from idle to rated load.

Emergency fuel supply: When main fuel pumps fail, backup gear pumps (flow 10-15m³/h) automatically start, supplying fuel to main engines through independent pipelines to maintain low-speed ship navigation (≥5 knots) and buy time for repairs.

3. Special Fuel Conveyance

High-sulfur heavy oil conveyance: Ocean-going oil tankers use stainless steel gear pumps (flow 20-30m³/h) to deliver heavy oil with 3.5% sulfur content, heated to 100℃ via heating jackets to reduce viscosity to 100cSt, meeting low-speed engine combustion requirements without pump body corrosion.

Polar low-temperature fuel supply: In -30℃ ice zone navigation, gear pumps with preheating functions (5kW power) deliver -20℃ low-sulfur diesel (with 3% anti-freeze additives), heating oil temperature to 10℃ (15cSt viscosity) within 3 minutes, maintaining flow 5-10m³/h and ensuring normal startup of research vessel main engines.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Fuel type: Cast iron pumps for light diesel and inland ships; bronze alloy pumps for heavy diesel and coastal ships; stainless steel pumps for heavy oil and ocean-going ships

Flow calculation: Configure 1.3 times the maximum fuel consumption of main engines; e.g., a main engine consuming 5m³/h requires flow ≥6.5m³/h

Pressure requirements: 3.0-5.0MPa for low-speed engines and heavy oil systems; 1.5-3.0MPa for medium-speed engines and light diesel; 0.8-1.5MPa for auxiliary engines

2. Maintenance Points

Daily monitoring: Check outlet pressure (fluctuation ≤±0.05MPa), gearbox temperature (≤80℃), and mechanical seal leakage (≤0.3mL/h) every 500 hours

Regular maintenance: Replace inlet filters every 2000 hours; replace mechanical seals (oil-resistant fluoroelastomer) every 6000 hours; inspect gear meshing clearance (maximum allowable 0.08mm)

Fuel cleanliness management: Test fuel particle size monthly (≤18/15 NAS grade); replace filters promptly if exceeding standards to avoid gear wear

3. Compliance Inspection

Annual classification society inspection, focusing on verification of volumetric efficiency (≥90%), explosion-proof performance, and compatibility with fuel systems

Meets IMO safety requirements for fuel systems, ensuring fuel pumps match injection systems and achieve qualified combustion efficiency (smoke concentration ≤0.5m⁻¹)

VI. Compliance and Certification

International standards: Complies with ISO 8661 marine fuel pump performance standards and IMO MSC.285(86) fuel system safety guidelines

Classification society certifications: Obtained type approval for gear fuel pumps from RS, LR, ABS, and CCS (including 3000-hour heavy oil operation tests)

Environmental requirements: Compatible with low-sulfur fuel, meeting IMO 2020 global sulfur emission limits (≤0.5%)