Marine Cast Iron Screw Cargo Oil Pump

1. Product Overview

The marine cast iron screw cargo oil pump is a core specialized equipment in ship cargo transportation systems and power supply systems. Specifically designed for ship cargo oil loading/unloading, fuel transfer, lubricating oil circulation, and various oil replenishment operations, its core function is to achieve stable suction and transportation of oil products through the meshing rotation of twin-screws or triple-screws. By forming a closed cavity via screw meshing, it can stably transport oil products of different viscosities (such as diesel oil, heavy oil, lubricating oil, and cargo oil), ensuring efficient progress of ship cargo handling and continuous supply of oil for power systems.

The equipment adopts high-quality grey cast iron for core components including the pump body, screws, pump cover, and base, combined with oil-resistant and temperature-resistant sealing assemblies and reinforced transmission shafts. It features a compact structure, stable operation, pulsation-free transportation, impact load resistance, and economic cost-effectiveness, making it adaptable to complex marine operating conditions such as high humidity, strong salt spray, severe vibration, and oil containing small amounts of impurities faced by various ocean-going and coastal ships.

As the "core hub of ship oil transportation," the marine cast iron screw cargo oil pump strictly complies with international and domestic standards such as the International Convention for the Safety of Life at Sea (SOLAS), IMO's "Rules for the Construction and Equipment of Ships," GB/T 10832-2011 "Marine Pumps," and GB/T 18154-2019 "Technical Specifications for Screw Pumps." It has obtained certifications from major classification societies including China Classification Society (CCS) and American Bureau of Shipping (ABS), and is widely used in various ships such as 500-200,000 DWT ocean-going cargo ships, oil tankers, container ships, bulk carriers, coastal transport ships, inland river cargo ships, and offshore operating platforms.

Compared with stainless steel screw pumps, cast iron materials optimize costs through mature casting processes. Meanwhile, through targeted oil-resistant and rust-proof treatments and enhanced sealing designs, it can fully meet the basic operational requirements of various ship oil transportation, becoming the preferred oil transportation equipment for small and medium-sized ships and conventional cargo ships, and building a "transportation line of defense" for efficient ship cargo transportation and stable power supply.

2. Core Technical Parameters

Pressure Range: Rated working pressure 0.6-2.5 MPa, maximum working pressure up to 3.0 MPa, pressure fluctuation error ≤±1.5%. It can meet the transportation pressure requirements for cargo oil loading/unloading, long-distance oil transfer, and multi-layer oil storage tanks, ensuring stable and controllable oil transportation.

Flow Rate Range: 10-500 m³/h, which can be customized in grades according to the ship's cargo tonnage (500-200,000 DWT) and oil loading/unloading efficiency requirements. Under rated conditions, the flow stability error ≤±2%, adapting to oil transportation needs of different cargo scales.

Medium Adaptability: Can stably transport various commonly used ship oils such as diesel oil, heavy oil, lubricating oil, and cargo oil; suitable for medium viscosity range 5-1500 mm²/s, impurity content ≤0.5% (particle size ≤3mm); applicable medium temperature range -10℃ to 150℃, capable of coping with navigation in low-temperature sea areas and transportation of high-temperature oil products (such as heated cargo oil).

Material Parameters: Pump body, screws, and pump cover are made of grey cast iron (with dual treatments of oil-resistant and rust-proof spray painting + electrophoretic coating); transmission shaft is made of steel (with chrome-plated hardening treatment); seals adopt a composite structure of fluororubber (FKM) + polytetrafluoroethylene (PTFE), featuring excellent oil resistance, temperature resistance, and corrosion resistance to ensure leak-free oil transportation.

Drive Mode: Mainstream adopts special marine asynchronous motor drive (Protection Class IP55, Insulation Class F); optional diesel engine drive or hydraulic motor drive mode; the motor supports 220V/380V/440V standard marine voltages. The drive system is equipped with overload, overheating, phase loss, and abnormal pressure protection functions, and can be linked with the ship's central control system (PLC) to realize automatic start/stop and flow regulation.

Operational Performance: Volumetric efficiency ≥93%, total efficiency ≥88%; Net Positive Suction Head (NPSH) ≤4.0 m, self-priming height ≥3.0 m, self-priming time ≤40 seconds (at 2m suction lift); operating noise ≤75 dB(A), vibration acceleration ≤1.2 m/s²; continuous operating life ≥10,000 hours, supporting 24/7 continuous oil loading/unloading operations to meet the uninterrupted cargo transportation needs of ships.

3. Structural Design and Core Advantages

3.1 Core Structural Design

Precision Screw Meshing Structure: Adopts twin-screw or triple-screw meshing design. The screws are precision ground, with a meshing gap controlled at 0.01-0.03 mm, forming a closed transportation cavity to achieve pulsation-free and stable oil transportation, avoiding oil splashing or impact. The screw helix is optimized based on fluid mechanics to improve transportation efficiency and reduce energy consumption.

Integrally Formed Cast Iron Pump Body: The pump body and base are integrally cast without spliced welds, featuring a compact and robust structure with strong impact rigidity, capable of withstanding ship during navigation and pressure fluctuations during oil transportation. The pump body flow channel is optimized to reduce oil transportation resistance and improve efficiency.

Enhanced Oil-Resistant Sealing System: Adopts a "mechanical seal + oil seal" dual sealing structure. The sealing surface is made of silicon carbide-graphite composite material, and the seal lip structure is optimized for oil transportation characteristics, effectively resisting erosion by various oils with a leakage rate ≤0.01 mL/h. A seal cavity cooling jacket is equipped to reduce the operating temperature of sealing components and avoid seal failure caused by high-temperature oil.

Intelligent Monitoring and Protection Module: Equipped with a standardized intelligent control box that real-time monitors oil transportation pressure, flow rate, pump body operating temperature, and seal cavity status parameters, with data synchronizable to the ship's central control system. It supports linkage with oil loading/unloading sensors to realize precise flow regulation and automatic overload protection, while providing fault alarm and historical data query functions for crew to quickly troubleshoot problems.

3.2 Core Technical Advantages

Stable and Pulsation-Free Transportation: Relying on the precision screw meshing structure, oil transportation is pulsation-free and impact-free, effectively protecting ship oil transportation pipelines and valve components, and avoiding pipeline vibration or leakage caused by pulsation. It is particularly suitable for transporting high-viscosity oils (such as heavy oil), with transportation stability far exceeding that of centrifugal pumps.

Economical, Durable, and Cost-Controllable: Grey cast iron raw materials are easily available and casting processes are mature. Compared with stainless steel screw cargo oil pumps, the procurement cost is reduced by 40%-60%, and maintenance parts are affordable. The cast iron material undergoes dual oil-resistant and rust-proof treatments, resisting erosion by various ship oils and adapting to the marine high-salt-spray environment, with a long service life, significantly reducing the procurement and operation and maintenance costs of ship cargo equipment.

Adaptability to Complex Oils and Operating Conditions: Can stably transport various oils such as diesel oil, heavy oil, lubricating oil, and cargo oil, adapting to the transportation needs of oils with different viscosities and temperatures. It has excellent low-temperature startup performance (normal startup at -10℃), capable of coping with navigation in polar and frigid sea areas. The impact-resistant and vibration-resistant design adapts to ship conditions, ensuring continuous and stable oil transportation.

Easy Maintenance and Operation: Key components adopt a modular design.parts such as screws and seals can be quickly disassembled and replaced with simple tools without overall disassembly of the pump body. Daily maintenance only requires regular inspection of oil cleanliness, cleaning of the inlet filter, and replenishment of oil-resistant lubricating oil, with a long maintenance cycle (regular maintenance interval ≥6 months), reducing the maintenance workload of the crew.

Safe, Compliant, and Wide Adaptability: Strictly complies with international and domestic ship safety and oil transportation equipment standards, passing multiple rigorous tests such as classification society oil transportation performance testing, pressure testing, leakage testing, vibration testing, and salt spray corrosion testing. It is adaptable to the oil transportation systems of various 500-200,000 DWT cargo ships, and can be simply customized according to cargo tonnage and oil type, with strong adaptability.

4. Typical Application Scenarios

4.1 Ship Cargo Oil Loading/Unloading and Transportation

Cargo oil loading/unloading is a core operation link of cargo ships, requiring high stability and efficiency of oil transportation. The marine cast iron screw cargo oil pump, with its pulsation-free and stable transportation characteristics, can avoid splashing and leakage during cargo oil loading/unloading, ensuring the safety of loading/unloading operations. The rated flow rate of 10-500 m³/h can adapt to the loading/unloading efficiency needs of ships of different tonnages. Combined with the intelligent flow regulation function, it can precisely control the loading/unloading speed and improve operation efficiency. The oil-resistant sealing design can effectively resist cargo oil erosion, ensuring leak-free long-term loading/unloading operations.

4.2 Ship Fuel Oil Storage and Replenishment

Ship fuel oil needs to be transferred and replenished between different storage tanks, requiring high self-priming capacity and transportation stability of the pump. The marine cast iron screw cargo oil pump has a self-priming height ≥3.0 m, eliminating the need for additional priming water and enabling rapid fuel tank transfer. The stable transportation characteristics avoid bubble generation during fuel transfer, ensuring fuel quality. The oil-resistant and rust-proof material adapts to the long-term contact environment with fuel oil, having a long service life and reducing the failure risk of the fuel replenishment system.

4.3 Ship Lubricating Oil Circulation and Transportation

The lubricating oil of ship main engines, auxiliary engines, and other power equipment needs to be circulated for lubrication and heat dissipation, requiring strict transportation precision and stability of the pump. The marine cast iron screw cargo oil pump has a flow stability error ≤±2%, which can precisely control the lubricating oil circulation flow, ensuring sufficient lubrication of all components of power equipment. Low-noise and low-vibration operation does not affect the working environment of power equipment. The temperature-resistant sealing design can cope with high-temperature conditions during lubricating oil circulation, ensuring the stable operation of the circulation system.

4.4 Oil Transportation for Coastal/Inland River Cargo Ships

Coastal/inland river cargo ships operate in complex environments with limited maintenance conditions, requiring high economy and durability of the pump. The marine cast iron screw cargo oil pump is low-cost and easy to maintain, adapting to the marine high-salt-spray and strong vibration environment, and stably providing cargo oil loading/unloading and fuel replenishment services for cargo ships. Its strong self-priming capacity can meet the oil transportation needs during operations in shallow inland river areas, and it can be quickly started in emergency situations to ensure the continuous progress of cargo transportation operations.

4.5 Auxiliary Oil Transportation for Special Cargo Ships (Oil Tankers, Chemical Tankers)

The main oil transportation systems of special cargo ships such as oil tankers and chemical tankers need supporting auxiliary oil transportation equipment for operations such as inter-tank trimming and residual oil recovery. The marine cast iron screw cargo oil pump adapts to the characteristics of high-viscosity oil transportation, effectively recovering residual oil in tanks and improving cargo transportation efficiency. The enhanced sealing design avoids oil leakage and marine environmental pollution. The impact-resistant and vibration-resistant design adapts to the complex navigation conditions of special cargo ships, ensuring the safe and efficient operation of auxiliary oil transportation.