The working principle of a signal butterfly valve.

Signal butterfly valves utilize an input module to monitor their physical wiring and operating principles. Signal butterfly valves are typically installed in fire sprinkler systems（
fire fighting system
）. Essentially, the signal butterfly valve feeds back its open and closed status via an output switch signal to the input module, which then transmits this information to the fire alarm control panel.

The normal operating state of a signal butterfly valve is typically open.  The signal butterfly valve has a single output switch signal wire. The input module’s monitoring line is connected to this feedback output line to monitor the valve’s open and closed status. For example, if the signal butterfly valve is in an open or closed state, this information is transmitted to the module via the switch signal, and the module then transmits it to the fire alarm control panel, thus completing the monitoring process.

Signal butterfly valves are available in wafer-type and grooved-end configurations, allowing for selection based on the connection method.