Dredging machinery has a small volume and fuel tank capacity, resulting in a small amount of lubricating oil. During operation, the oil temperature is high, requiring the lubricating oil to have good thermal stability and oxidation resistance.
Due to the harsh environment of river water, with a high content of coal dust, rock dust, and moisture, the lubricating oil is inevitably contaminated by these impurities. Therefore, the lubricating oil for suction dredgers needs to have good rust prevention, corrosion resistance, and anti-emulsification properties; and its performance should not change significantly when contaminated, meaning it should have low sensitivity to contamination.
Open-air machinery experiences significant temperature variations between summer and winter, and some regions also have large diurnal temperature differences. Therefore, the viscosity of the lubricating oil should change minimally with temperature. It should prevent the oil viscosity from becoming too low at high temperatures, which would prevent the formation of a lubricating film and hinder proper lubrication. Conversely, it should also prevent the viscosity from becoming too high at low temperatures, which would make starting and operation difficult.
For some dredging machinery and equipment (composed of: driving device, transmission device, etc.), especially those used in mines where fires and accidents are prone to occur, lubricants with good fire resistance (fire-resistant fluids) are required, and flammable mineral oils should not be used.
The lubricant should have good compatibility with sealing components to prevent damage to the seals.
