What is the difference between preventive maintenance and condition-based maintenance in the context of pumps?

• A. Preventive uses calendar intervals; condition-based uses measurements to trigger service
• B. Condition-based maintenance relies solely on calendars
• C. Condition-based uses calendar intervals
• D. Preventive maintenance uses random inspections

Answer: (D)

The key idea is how maintenance timing is decided. Preventive maintenance is planned and scheduled, based on a calendar or defined running hours, so you service the pump at regular, fixed intervals to reduce the chance of failure. Condition-based maintenance, on the other hand, uses real measurements from the pump—like vibration, temperature, oil quality, flow or pressure—and you perform service only when those indicators show wear or abnormal performance. This makes maintenance responsive to actual condition rather than just time. For example, you might set a six-month preventive inspection, but also continuously monitor vibration and temperature; if the readings exceed thresholds, you trigger maintenance. The notion of random inspections isn’t how preventive maintenance is designed to work, since preventive maintenance is intentionally planned rather than arbitrary.