Which component is NOT part of an automatic sprinkler system?

An automatic sprinkler system is designed to activate and deliver water during a fire without the need for human intervention, making its components critical to its functionality. The system typically consists of automatic sprinkler heads that release water when they detect heat, piping that transports the water, and a dedicated water supply that ensures consistent and adequate pressure.

Human-operated control valves, however, are not a standard part of the automatic mechanism. They require manual operation to control the water flow, which contrasts with the system's overall purpose of providing automated fire protection. The reliance on human intervention can delay the system's response during a fire, undermining its effectiveness. Therefore, the presence of human-operated control valves distinguishes them from the essential, automated components that define an automatic sprinkler system.