Marine Gear Cargo Oil Pump

I. Product Overview

Marine gear cargo oil pumps are the "core power equipment" of ship cargo oil loading and unloading systems, designed specifically for the transportation, loading, unloading, and inter-tank transfer of cargo oils such as crude oil, diesel, fuel oil, and lubricating oil. They ensure efficient cargo oil transfer through stable pressurization. Constructed with cast iron (HT200), bronze alloy (ZCuSn10Pb2), 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 oil from cargo tanks, pressurize it, and deliver it to onshore storage tanks, barges, or other cargo tanks via pipelines. The pump body undergoes anti-corrosion treatment and precision machining, with a corrosion-resistant service life of ≥8 years in -10℃~120℃ environments. It meets IMO International Convention for the Prevention of Pollution from Ships (MARPOL Annex I) and cargo oil pump certification requirements of classification societies such as RS, LR, ABS, and CCS, widely used in cargo oil systems of oil tankers, chemical tankers, multi-purpose cargo ships, and other transport vessels.

II. Core Technologies and Material Characteristics

1.Material Selection and Performance

2.Key Technical Parameters

Flow range: 5-500m³/h, suitable for ships of 1000-100,000 gross tons (e.g., 50,000 gross ton oil tankers require single pump flow ≥200m³/h)

Pressure coverage: 0.6-3.0MPa, meeting pressure requirements for transportation from cargo oil tanks to onshore storage tanks (including pipeline elbows, valves, and flowmeter resistance losses)

Medium compatibility: Capable of conveying crude oil, diesel, fuel oil, lubricating oil, etc., adapting to cargo oils with viscosity 5-1000cSt (high viscosity requires heating) and temperature -10℃~120℃

Volumetric efficiency: ≥95% under design conditions, 3% higher than screw pumps of the same specification; maintains ≥90% efficiency in heavy fuel oil with 500cSt viscosity

Self-priming performance: Self-priming height ≥2.5m, priming time ≤60 seconds, suitable for oil suction from low-level cargo oil tanks without external priming devices

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 in cargo oil tank zones to prevent explosion risks from oil and gas leakage

Overload protection: Safety valves automatically open (returning oil to the suction end) when outlet pressure exceeds 1.2 times the rated value, avoiding pipeline rupture due to overpressure

Axial clearance compensation: Uses spring-loaded mechanical seals to automatically compensate for axial clearance caused by gear wear, ensuring stable long-term operation efficiency

III. Technical Advantages and Innovative Design

1. High-Viscosity Cargo Oil Conveying Capacity

Helical gear meshing structure: Uses 25° helix angle helical gears, increasing meshing overlap coefficient by 50% compared to spur gears. In heavy fuel oil with 1000cSt viscosity, pressure fluctuation ≤±0.05MPa, with operating noise ≤85dB (at 1 meter).

Integrated heating jacket: Pump bodies and gearboxes are externally wrapped with heating jackets (working pressure 1.0MPa), allowing steam or hot oil to heat high-viscosity cargo oil (e.g., crude oil) from ambient temperature to 80℃, reducing viscosity to below 100cSt and ensuring smooth conveyance.

2. Wear and Corrosion Resistance Enhancement

Stainless steel gear surface treatment: 316L gears undergo nitriding treatment, achieving surface hardness HV600, improving resistance to sediment wear in cargo oil by 60% compared to ordinary stainless steel, and extending service life to 15,000 hours.

Bronze pump anti-adhesion design: Bronze alloy gear tooth surfaces undergo mirror polishing (Ra≤0.8μm), reducing adhesion and deposition of high-viscosity cargo oil, extending cleaning intervals to 500 hours, and reducing maintenance frequency by 40% compared to ordinary gear pumps.

3. Adaptability to Ship Operating Conditions

Vibration-resistant structure: Pump units and bases adopt damping shock absorbers + steel spring composite damping with vibration acceleration ≤5m/s², ensuring stable operation in high-vibration main engine room environments (flow fluctuation ≤2%).

Modular assembly: Gears, bearings, and seals feature a modular design, reducing replacement time to ≤4 hours, supporting emergency repairs at sea, and minimizing ship port stay time.

IV. Typical Application Scenarios

1. Cargo Oil Loading and Unloading Operations

Crude oil loading: 100,000 gross ton crude oil tankers use stainless steel gear cargo oil pumps (flow 300-500m³/h, pressure 2.0MPa) to heat crude oil to 60℃ (150cSt viscosity) via heating jackets, cooperating with flowmeters for precise loading, with a single pump capable of loading 4000 tons of crude oil per hour.

Product oil unloading: 5000 gross ton product oil tankers use bronze alloy gear pumps (flow 50-100m³/h, pressure 1.6MPa) to deliver diesel from cargo oil tanks to onshore storage tanks, with volumetric efficiency ≥96% and ensuring unloading loss rate ≤0.1%.

2. Inter-tank Cargo Oil Transfer

Oil tanker cargo tank balancing: When large oil tankers need to adjust oil levels in various tanks during navigation, gear cargo oil pumps (flow 100-200m³/h, pressure 1.2MPa) transfer cargo oil from full tanks to empty tanks via cross-tank pipelines, completing 1000m³ oil transfer within 30 minutes to ensure ship stability.

Chemical tanker compartmented conveyance: Multi-purpose chemical tankers transporting different grades of diesel use bronze gear cargo oil pumps (flow 30-50m³/h) to achieve independent conveyance of different cargo tanks by quickly switching valves, avoiding oil mixing and contamination.

3. Special Cargo Oil Conveyance

High-sulfur crude oil conveyance: Ocean-going oil tankers transporting crude oil with 3.5% sulfur content use 316L stainless steel gear cargo oil pumps (flow 200-300m³/h) to resist hydrogen sulfide corrosion in crude oil, operating continuously for 1000 hours without leakage and showing no significant rust on pump bodies.

Low-temperature cargo oil loading/unloading: In -10℃ port environments, cast iron gear pumps with heating jackets (flow 50-80m³/h) convey diesel, maintaining oil temperature above 10℃ through heating to prevent pipeline blockage from diesel wax precipitation at low temperatures.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Cargo oil type: Cast iron/bronze pumps for light diesel and fuel oil; stainless steel pumps for crude oil and high-sulfur oil; corrosion-resistant bronze or 316L pumps for chemicals

Flow calculation: Configure 1.2 times the maximum loading/unloading rate of the ship; e.g., an oil tanker loading 500 tons of oil per hour (crude oil density 0.9t/m³) requires flow ≥667m³/h

Pressure requirements: 0.6-1.6MPa for short-distance conveyance (inter-tank transfer); 1.6-3.0MPa for onshore loading/unloading; high-pressure models (≥2.5MPa) for high-viscosity cargo oil

2. Maintenance Points

Daily monitoring: Check outlet pressure (fluctuation ≤±0.1MPa), bearing temperature (≤80℃), and mechanical seal leakage (≤5mL/h) every 800 hours

Regular maintenance: Replace mechanical seals (oil-resistant fluoroelastomer) every 3000 hours; clean inlet filters (50μm aperture); inspect gear wear (tooth side clearance ≤0.1mm)

Cargo oil switching maintenance: Flush pump chambers and pipelines with low-viscosity diesel before conveying different grades of cargo oil to avoid mixing contamination; fill pumps with anti-rust oil (e.g., No. 20 machine oil) during long-term shutdown

3. Compliance Inspection

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

Meets MARPOL Annex I requirements for cargo oil loading/unloading systems, ensuring cargo oil leakage rate ≤0.05% and compliance with environmental emission regulations

VI. Compliance and Certification

International standards: Complies with ISO 13709 marine gear pump design standards and IMO MARPOL Annex I cargo oil system specifications

Classification society certifications: Obtained type approval for gear cargo oil pumps from RS, LR, ABS, and CCS (including 2000-hour heavy fuel oil operation tests)

Safety requirements: Overall pump unit explosion-proof grade reaches Ex d IIB T4 Gb, meeting SOLAS Convention requirements for equipment in hazardous areas