Marine Cast Steel Lubricating Oil Pump

I. Product Overview

Marine cast steel lubricating oil pumps serve as the "blood supply hub" of ship power systems, specifically designed for lubricating oil circulation and lubrication of large power equipment such as diesel engines and gas turbines. Constructed with high-strength alloy cast steel (WC6/WC9) or carbon cast steel (WCB), they achieve high-pressure, high-precision lubricating oil delivery through the principles of gear pumps or screw pumps. Their working principle involves a power source driving gear meshing or screw rotation to generate volume changes, drawing lubricating oil from the tank, pressurizing it, filtering it through an oil filter, and delivering it to friction parts such as equipment bearings and gears to form an oil film that reduces wear and dissipates heat. The pump body undergoes integral forging and oil-resistant anti-corrosion treatment, with a corrosion-resistant service life of ≥15 years in oil temperatures ranging from -20℃ to 120℃ and various lubricating oil media. It meets the IMO Code for Shipboard Machinery Installations and certification requirements of classification societies such as LR and ABS, widely used in power systems of oil tankers, LNG carriers, ocean-going cargo ships, and offshore platforms.

II. Core Technologies and Material Characteristics

1.Cast Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 5-200m³/h, suitable for power equipment with power 500-20,000kW

Pressure range: Gear pumps 1.0-4.0MPa, screw pumps 2.5-6.0MPa, meeting lubrication pressure requirements of different equipment

Medium compatibility: Capable of transporting mineral oil, synthetic lubricating oil, and special lubricating oil with additives, with viscosity 10-1000cSt

Precision control: Flow pulsation rate ≤3%, pressure fluctuation ≤±2%, ensuring stable lubricating film

Temperature adaptability: Continuous operation at -20℃~120℃; high-temperature models can withstand short-term 150℃ impact

3.Safety Performance

Built-in overload protection device, automatically shutting down when outlet pressure exceeds 1.2 times the rated value

Adopting leak-free mechanical seal, with leakage ≤0.5mL/h, meeting the requirements of zero discharge of ship oil pollution

III. Technical Advantages and Innovative Design

1. High-Precision Lubrication Assurance

Positive displacement precision structure: Twin-screw pumps adopt 5:6 tooth ratio design, with meshing clearance controlled at 0.02-0.05mm and flow precision up to ±1%, ensuring stable lubricating oil quantity for key bearings.

Pressure closed-loop control: Integrating pressure sensors and frequency conversion speed regulation systems, real-time adjusting pump speed to keep outlet pressure within ±0.05MPa of the set value, adapting to lubrication needs ofequipment under different working conditions.

2. Extreme Condition Adaptability

Low-temperature start-up optimization: The pump body integrates an electric heating jacket, which can preheat lubricating oil to 30℃ in -20℃ environment, reducing starting torque by 40% and avoiding insufficient lubrication during cold start.

High-temperature anti-coking design: Flow-through components undergo nitriding treatment (surface hardness HV800), with no coking in 120℃ high-temperature lubricating oil, and oil circuit flow capacity retention rate ≥95%.

3. Long Life and Low Maintenance

Wear-resistant friction pair: Gears/screws adopt carburized alloy cast steel (20CrNiMo), with surface hardness up to HRC62, 5 times more wear-resistant than ordinary cast steel, and trouble-free operation cycle exceeding 80,000 hours.

Online maintenance structure: The pump cover and pump body adopt a quick-opening flange design, allowing replacement of filter elements and seals without disassembling pipelines, with single maintenance time ≤1 hour.

IV. Typical Application Scenarios

1. Lubrication of Main Engines and Power Equipment

Low-speed diesel engine lubrication: 100,000-ton cargo ship main engines are equipped with alloy cast steel screw pumps, with flow 50-100m³/h and pressure 4.0MPa, providing forced lubrication for key parts such as crossheads and main bearings, and controlling oil temperature at 55±5℃.

Gas turbine lubrication: LNG carrier gas turbines adopt WC9 alloy cast steel lubricating oil pumps, with flow 20-50m³/h and pressure 5.0MPa, adapting to bearing lubrication needs in high-temperature flue gas environments.

2. Auxiliary Machinery and Transmission Systems

Generator bearing lubrication: Cruise ship diesel generators are matched with gear-type lubricating oil pumps, with flow 5-20m³/h and pressure 1.5MPa, precisely supplying oil to each bearing point through a progressive distributor.

Propulsion shafting lubrication: Engineering ship propulsion shafting adopts self-priming cast steel lubricating oil pumps, with self-priming height ≥5m and flow 30-80m³/h, ensuring continuous lubrication of underwater bearings.

3. Special Vessels and Platforms

Low-temperature lubrication of polar research ships: In -30℃ environment, through fuel preheating and pump body insulation design, the lubricating oil pump can start within 30 seconds under extremely cold conditions to supply oil to the icebreaker power system.

Compressor lubrication of drilling platforms: Offshore platform air compressors are equipped with high-temperature lubricating oil pumps, operating stably at 120℃, with flow 10-30m³/h and pressure 3.5MPa.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Equipment type: Screw pumps for low-speed diesel engines, high-pressure gear pumps for high-speed gas turbines, and economical gear pumps for auxiliary machinery

Flow calculation: Configure according to 1.2 times the total oil consumption of equipment lubrication points; for example, 8,000kW main engines recommend flow 80-120m³/h

Oil characteristics: WC6 alloy cast steel type for high-temperature lubricating oil (≥100℃), and heating jacket type for low-temperature oil (≤-10℃)

2. Maintenance Key Points

Daily monitoring: Check outlet pressure (fluctuation ≤±0.1MPa), oil temperature (≤100℃), and vibration value (≤2.8mm/s) every 500 hours

Regular maintenance: Replace lubricating oil filter elements (precision ≤10μm) monthly, detect oil viscosity (change rate ≤10%) every six months, and replace mechanical seals annually

In-depth maintenance: Disassemble and inspect gear/screw wear (tooth thickness loss ≤0.1mm) every 6 years, re-grind the mating surface, and calibrate flow precision

VI. Compliance and Certification

International standards: Complies with IMO MSC.389(94) ship machinery lubrication system specifications and ISO 12153 lubricating oil pump technical requirements

Classification society certifications: Passed type approval by LR, ABS, DNV GL, and other institutions

Environmental certifications: Meets MEPC.107(49) anti-pollution standards for ship machinery spaces, with no risk of lubricating oil leakage