Why does the backflow test need to be completed annually?
Federal law requires water suppliers to protect their water systems from contamination or pollution by cross-connections. Backflow preventers must be tested at least once each year to ensure that they are performing properly in preventing backflow. When necessary they must be repaired in order to assure proper operation.
What is a backflow preventer?
A backflow preventer is a means or mechanism to prevent backflow. The basic means of preventing backflow is an air gap, which either eliminates a cross-connection or provides a barrier to backflow. The basic mechanism for preventing backflow is a mechanical backflow preventer, which provides a physical barrier to backflow. The principal types of mechanical backflow preventer are the reduced-pressure principle assembly, the pressure vacuum breaker assembly, and the double check valve assembly.
Why do backflow preventers have to be tested periodically?
Mechanical backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested with properly calibrated gauge equipment.