Marine Screw Pump

I. Product Overview

Marine screw pumps are positive displacement rotary conveying equipment. They form a closed cavity through the meshing rotation of the driving screw and driven screw to achieve stable suction and discharge of media, serving as the core equipment for the transportation system of high-viscosity and impurity-containing media on ships. The product has core advantages such as stable and pulse-free flow, strong anti-clogging capacity, excellent self-priming performance, low noise and vibration, and wear and corrosion resistance. It can be widely adapted to various media including crude oil, heavy fuel oil (HFO), diesel oil, lubricating oil, bilge water, mud with solid content ≤10% (particle size ≤10mm), and low-concentration chemicals, especially suitable for high-viscosity media (viscosity 1-1000cSt) transportation scenarios. The main body is made of 316L stainless steel, cast iron, and the rotor is integrally forged from alloy steel. It is suitable for media temperatures ranging from -40℃ to 150℃ with a service life of ≥10 years. Fully complying with IMO "Code for the Safety of Ship Fuel Systems" (MSC.389(94)), ISO 15749 marine positive displacement pump standards and API 676 screw pump technical specifications, the product has obtained type approval from mainstream classification societies such as CCS, LR, ABS, and RS. It is widely used in key systems of various ships such as oil tankers, cargo ships, chemical tankers, fishing boats, and research vessels, including fuel transportation, bilge water treatment, lubricating oil circulation, and special medium transfer.

II. Core Technologies and Material Characteristics

1. Key Technical Parameters

Flow Range: 5-200m³/h. Different transportation requirements are adapted according to the number of screw heads (single/twin/triple screw) and rotation speed (triple screw pumps have the best flow stability, and single screw pumps have the strongest anti-clogging performance)

Output Pressure: 0.3-5.0MPa. Pressure grading can be achieved by adjusting the rotation speed or selecting different specifications of screws, meeting the requirements of fuel transportation (1.5-3.0MPa), sewage lifting (0.3-1.0MPa), high-pressure flushing (3.0-5.0MPa), etc.

Medium Compatibility: Capable of transporting crude oil, heavy fuel oil (HFO), No. 0 diesel oil, 46-150# lubricating oil, sewage/mud with solid content ≤10% (particle size ≤10mm), and low-concentration acid-base solutions (pH 3-11), suitable for media viscosity 1-10000cSt

Speed Range: 300-1500r/min. It can be directly linked and driven with marine diesel engines and generators without additional transmission devices, adapting to power systems of ships with different powers

Self-priming Performance: Self-priming height ≥4.5m, priming time ≤60 seconds (for clean water). It can start without priming and directly suck liquid from the low-lying cabins and the bottom of storage tanks of ships

Suction Pressure: Allowable suction pressure -0.08~0.1MPa. It can adapt to negative pressure cabins or high liquid level difference transportation scenarios, avoiding cavitation damage

2. Safety Protection Design

Dry Running Protection: Built-in temperature sensor and mechanical wear monitoring device. An alarm is automatically triggered and the machine shuts down within 30 seconds of dry running to avoid dry friction damage between the rotor and the bushing

Overload Protection: Equipped with a safety relief valve and a torque limiter. When the outlet pressure exceeds 1.1 times the rated value or the torque exceeds 1.2 times the rated value, it automatically relieves pressure and cuts off power transmission to protect the pump body and drive system

Efficient Sealing Design: Adopts a double structure of cartridge mechanical seal + labyrinth seal. The sealing surface is made of silicon carbide-silicon carbide paired materials with leakage ≤0.01mL/h, adapting to the sealing requirements of high-temperature and high-viscosity media

Vibration and Impact Resistance: The pump body and base adopt an elastic shock absorber + buffer spring design, which can withstand ship heel ±30°, trim ±20°, and vibration acceleration of 15g, with flow attenuation ≤3%

Explosion-proof Adaptation: Models for fuel transportation and chemical transfer can be equipped with Ex d IIB T4 Gb explosion-proof motors, adapting to Zone 1/2 hazardous areas on ships with no ignition risk

III. Technical Advantages and Innovative Design

1. Stable Flow and Efficient Transportation Core

Meshing Optimization Design: Adopts a screw meshing curve optimized by 3D simulation. The tooth surface fit is improved by 30%, the operating noise is ≤75dB(A), and the flow pulsation rate is ≤1%, which is much lower than that of vane pumps, avoiding impact on the pipeline system

High Viscosity Adaptation Technology: By optimizing the screw lead and tooth top clearance, it can still maintain more than 90% of the rated flow when the medium viscosity is 1000cSt, and the high-viscosity transportation efficiency is 25% higher than that of traditional screw pumps

Energy-saving Drive Design: An optional frequency conversion control system can automatically adjust the rotation speed according to the medium viscosity and transportation flow requirements, reducing energy consumption by 18%-25%, and avoiding energy waste when large flow is not needed

2. Enhanced Anti-clogging and Wear Resistance

Wide-channel Anti-clogging Structure: Single screw pumps adopt an eccentric rotor + elastic bushing design. The flow channel diameter is ≥50mm, which can pass fibers, sediment, and small particle impurities. The clogging rate is 70% lower than that of ordinary positive displacement pumps

Rotor Wear Resistance Upgrade: The surface of the alloy steel rotor is coated with WC-Co by plasma spraying, with hardness ≥HRC68. The wear resistance is improved by 60%, and the continuous operation life is ≥8000 hours (when transporting impurity-containing media)

Bushing Self-lubrication Design: The rubber bushing adopts a porous structure, which can absorb the lubricating oil in the medium to form a lubricating film, reducing the friction loss between the rotor and the bushing and extending the service life

3. Easy Operation and Maintenance

Modular Disassembly and Assembly Design: Core components such as the pump cover, rotor, and bushing adopt quick-release connections. Maintenance can be completed without disassembling the entire pipeline, and the replacement time of wearing parts is ≤40 minutes

Intelligent Status Monitoring: Equipped with pressure, temperature, vibration, and torque sensors to display key operating parameters in real time; an optional remote monitoring module can synchronize data to the ship's central control system, allowing operation and maintenance personnel to predict faults remotely

Generalization of Wearing Parts: The generalization rate of wearing parts such as seals, bearings, and bushings for different flow models is ≥85%, reducing the inventory pressure of ship spare parts and lowering operation and maintenance costs

4. Wide Scene Adaptability

Extreme Temperature Adaptation: Low-temperature models can be equipped with electric heating jackets (power 800W), which can quickly preheat the pump body and medium in -40℃ environments to avoid solidification and blockage of high-viscosity media; high-temperature models use high-temperature resistant seals and bearings, which can adapt to 150℃ high-temperature media

Special Ship Adaptation: Polar ship models adopt low-temperature resistant stainless steel + thermal insulation layer design, which can operate stably in -40℃ polar environments; chemical tanker models use perfluororubber seals + Hastelloy flow-through components, which can adapt to highly corrosive media

Multi-condition Compatibility: A single pump can realize multi-condition switching of "transportation-flushing-purging" by adjusting the rotation speed. For example, a fuel transfer pump can be switched to a pipeline flushing pump to improve equipment utilization

IV. Typical Application Scenarios

1. Ship Fuel Transportation System

Crude Oil/Heavy Fuel Oil Transportation for Oil Tankers: 100,000-ton oil tankers adopt duplex stainless steel twin screw pumps (flow rate 150-200m³/h, pressure 2.5MPa) to transport crude oil or heavy fuel oil to the main engine fuel tank. The high-viscosity adaptation capacity ensures smooth transportation of heavy fuel oil at -10℃, and the anti-corrosion design can withstand the erosion of sour crude oil

Main Engine Fuel Supply for Cargo Ships: 30,000kW cargo ships adopt triple screw pumps (flow rate 80-100m³/h, pressure 3.0MPa) to transport heavy fuel oil to the main engine. The stable and pulse-free flow ensures stable fuel supply to the main engine, and the frequency conversion control adapts to different load requirements of the main engine

2. Bilge Water and Mud Treatment

Bilge Water Lifting for Large Cargo Ships: Single screw pumps (flow rate 50-80m³/h, pressure 1.0MPa) are used to lift bilge water containing sediment and oil to the treatment system. The wide-channel design avoids blockage by fibers and impurities, and the wear-resistant bushing is suitable for scouring by particles in the sewage

Fishery Catch Washing Sewage Transportation for Fishing Boats: Coastal fishing boats adopt small single screw pumps (flow rate 5-10m³/h, pressure 0.6MPa) to transport washing sewage containing fishery catch residues. With small volume and light weight (≤40kg), it can be flexibly moved and installed, with strong anti-clogging capacity and no need for frequent cleaning

3. Lubricating Oil Circulation and Supply

Main Engine Lubricating Oil Circulation for Ships: 15,000kW main engines are equipped with triple screw pumps (flow rate 30-50m³/h, pressure 1.2MPa) to circulate and transport 150# lubricating oil to various moving parts of the main engine. The stable flow ensures uniform lubrication, and the low-noise operation does not interfere with the engine room environment

Auxiliary Engine Lubricating Oil Supply: Auxiliary engines of inland cargo ships adopt cast iron screw pumps (flow rate 10-20m³/h, pressure 0.8MPa) to supplement lubricating oil for auxiliary engines. It is cost-effective and operates stably, adapting to the anti-corrosion requirements of the inland fresh water environment

4. Special Medium Transfer

Special Medium Transfer for Chemical Tankers: Chemical tankers adopt 316L stainless steel single screw pumps (flow rate 20-30m³/h, pressure 2.0MPa) to transfer low-concentration acid-base solutions. The all-stainless steel flow-through components + fluororubber seals avoid medium corrosion, and the explosion-proof design ensures transportation safety

Mud Sampling and Transportation for Research Vessels: Deep-sea research vessels adopt high-pressure single screw pumps (flow rate 5-15m³/h, pressure 4.0MPa) to transport deep-sea mud to the laboratory for sampling. The high-pressure sealing design adapts to the deep-sea high-pressure environment, and the wear-resistant material can withstand scouring by particles in the mud

Product showcase:(In addition, please provide the parameter of the marine pump you need and we can customize the suitable type for you.)