What is a common cause of a valve not closing when operated from the clock?

• A. Electrical surges
• B. Debris stuck in the valve seat
• C. Water pressure changes
• D. Mechanical wear on the handle

Answer: (B)

The reason that debris stuck in the valve seat is the correct answer is based on the fundamental function of a valve within an irrigation system. Valves are designed to control the flow of water, and they rely on a clear and unobstructed pathway to operate correctly. When debris accumulates in the valve seat, it can prevent the valve from sealing properly, which may result in leakage or failure to close completely when commanded by the timer or control system. This situation disrupts the proper functioning of the entire irrigation system, as it compromises the ability to manage water flow effectively.

In contrast, while electrical surges can affect electronic components involved in the control of a valve, they do not directly cause the physical obstruction that leads to a valve failing to close. Moreover, while water pressure changes can influence the performance of a valve, they typically do not result in a valve not closing unless they are extreme and outside the operational range of the valve. Lastly, mechanical wear on the handle may lead to issues in manually opening or closing the valve, but does not specifically account for the valve's inability to close due to blockages in the seat itself.