Introducing the requirements for lubricants in dredgers:

The dredger has a smaller volume and fuel tank capacity, resulting in less lubricating oil being stored. During operation, the oil temperature is higher, which necessitates the lubricant to have excellent thermal stability and antioxidant properties.

2. Due to the harsh environmental conditions of river water, with abundant coal dust, rock dust, and moisture, lubricating oil is inevitably contaminated by these impurities. Therefore, it is required that the dredger's lubricating oil possess excellent anti-rust, anti-corrosion, and anti-foaming properties. It is also essential that the performance of the lubricating oil changes minimally when it becomes contaminated, meaning it should have a low sensitivity to pollution.

3. Outdoor machinery experiences significant temperature fluctuations between seasons, and some areas have large temperature differences between day and night. Therefore, it is required that the viscosity of lubricants changes minimally with temperature. This ensures that the oil does not become too thin at high temperatures, preventing the formation of a lubricating film and failing to provide proper lubrication, and also that it does not become too thick at low temperatures, making start-up and operation difficult.

4. For certain dredging equipment, especially machinery used in mines prone to fires and accidents, it is required to use high-fire-resistant lubricants (fire-resistant fluids) and not flammable mineral oils.