What is the function of a Normally Closed Valve?

A Normally Closed Valve is designed to remain closed to prevent water flow until it is activated by some external influence, such as an electric signal or manual operation. This type of valve is commonly used in irrigation systems to control the flow of water precisely. When the valve is not actuated, it blocks the water flow, allowing the system to maintain pressure and avoid unintended irrigation.

In practical application, if the irrigation system needs to stop water from passing through until a specific condition is met (like when a timer or sensor indicates it's time to irrigate), the Normally Closed Valve efficiently fulfills this requirement. Such functionality is crucial for maintaining the integrity of an irrigation system, ensuring that water is only delivered as intended, thus conserving water and preventing over-irrigation.

This function contrasts with other options that either describe continuous flow, draining action, or functions related to backflow prevention, which do not align with the specific operational characteristics of a Normally Closed Valve.