Oilers/Plant Tenders (HHC) Civil Service Practice Exam

Why is a gravity system of lubrication sometimes preferred to a direct pressure system?

1. It is more efficient

2. It requires less maintenance

3. There is a backup supply of oil in case of pump failure

4. It operates at a lower temperature

The correct answer is: There is a backup supply of oil in case of pump failure

A gravity system of lubrication is often preferred because it provides a backup supply of oil in case of pump failure. This is particularly important in environments where machinery must operate continuously and any disruption in oil supply could lead to overheating or damage to components. In a gravity system, oil flows down from a reservoir, ensuring that there is always a source of lubrication available, even if the pump fails. This redundancy is a significant advantage as it helps maintain operational integrity and minimizes the risk of costly breakdowns. While efficiency is a consideration in lubrication systems, direct pressure systems can often be more efficient due to their ability to deliver oil directly to where it is needed, increasing the lubrication rate and reducing friction. Maintenance is another factor, but gravity systems can still require regular attention to ensure the oil is clean and that the reservoir is filled. Finally, temperature management can differ between systems, but it is not a defining feature that makes gravity systems inherently operate at lower temperatures compared to direct pressure systems. The primary reason for preferring a gravity system is the reliable backup of lubrication it ensures in case of emergencies or equipment failure.