Wafer Butterfly Valve with Tamper Switch

  When the valve is operated (either manually or through an actuator), the rotation of the valve stem will drive the trigger arm of the signal feedback device to move. When the valve reaches the "fully open" or "fully closed" position, the trigger arm will press or release the internal microswitch. The change in the state of the microswitch (the normally open contact is closed or the normally closed contact is open) will generate a passive dry contact signal.

  This electrical signal is transmitted to the fire alarm control system or a dedicated monitoring module through the wires (usually 2-core or 4-core) led out by the signal device. Once the valve is accidentally closed (changing from the open state to the closed state), the control center will immediately receive an alarm signal of "valve closed" and issue an audible and visual alarm to alert the staff that there is an abnormality in the system and it may have failed.