Oilers/Plant Tenders (HHC) Civil Service Practice Exam

For a steam engine equipped with oil cups, what type of oil is considered a safe recommendation for bearing lubricant?

1. Light oil

2. Reasonably heavy oil

3. Synthetic oil

4. Waxy oil

The correct answer is: Reasonably heavy oil

When considering the lubrication of bearings in a steam engine equipped with oil cups, reasonably heavy oil is the safe recommendation. This is due to the operating conditions of a steam engine, where components can experience elevated temperatures and significant pressure. Reasonably heavy oil provides the necessary viscosity to form a strong lubricating film that can withstand these conditions, ensuring smooth operation and reducing wear on the bearings. Light oil may not provide adequate protection in high-temperature and high-pressure environments, as it can thin out and fail to maintain a sufficient lubricating layer. Synthetic oil, while useful in many applications, may not be the standard recommendation for traditional steam engines unless specified, and can come at a higher cost. Waxy oil is generally inappropriate for internal lubrication in steam engines, as it may lead to clogging and prevent efficient lubrication. Thus, the choice of reasonably heavy oil aligns with the requirements for effective lubrication in steam engine operations.