Why is it important to drain the pump casing before maintenance?

Draining the pump casing before performing maintenance is crucial for safety reasons and to prevent spills. When a pump is operating, it contains liquids that can be hazardous, potentially causing injury to maintenance personnel or leading to environmental contamination if spills occur. By draining the casing, workers eliminate the risk of being exposed to potentially toxic or harmful substances, ensuring a safe working environment. This practice also prevents any unintended discharges of liquids during the maintenance process, which could lead to messy and dangerous situations. Ensuring safety and minimizing the chances of a spill are paramount during maintenance procedures.