How should all vents and overflows on a storage tank be equipped?

Vents and overflows on a storage tank should be equipped with screens to prevent contaminants from entering the tank while allowing proper air exchange and overflow prevention. This screening is crucial because it serves to protect the water quality by filtering out debris, insects, and other foreign materials that could compromise the stored water.

Additionally, screens help in maintaining the overall efficiency of the tank's operation. Open vents might allow for unwanted contaminants to enter, while closed vents can lead to pressure build-up, potentially resulting in structural damage or tank failure. Similarly, while filtering may sound beneficial, it often implies a level of filtration not needed in this context and may restrict airflow. Hence, screening provides the right balance of coverage and operational integrity for storage tanks.