Oilers/Plant Tenders (HHC) Civil Service Practice Exam

What is a common trait of heat-resisting greases?

1. Low viscosity

2. Stable at high temperatures

3. Water-soluble

4. Highly flammable

The correct answer is: Stable at high temperatures

Heat-resisting greases are specifically formulated to maintain their consistency and performance when exposed to high temperatures, making the trait of stability at high temperatures fundamental to their purpose. These greases are designed to minimize degradation and maintain lubrication ability even in extreme heat conditions, which is crucial for applications involving machinery or equipment that generate significant heat during operation. The other options do not align with the characteristics of heat-resisting greases. Low viscosity is generally not a trait of heat-resisting greases, as they are usually designed to be thicker or have a higher viscosity to provide effective lubrication under heat. Water solubility is also not characteristic, as greases are hydrophobic, meaning they do not mix well with water. Lastly, being highly flammable is contrary to the intended use of these greases, as products designed for high temperatures must also have flame-resistant properties to ensure safe operation.