VT series switch type electric ball valve by the valve actuator and valve body composition. To control the opening or closing of the pipe system of the central air conditioning fan coil unit or the heating and heating system to achieve the purpose of controlling the temperature. By opening and closing of the valve, make indoor temperature kept the thermostat set temperature range, the series of electric valve actuator and valve with threaded connections, valves can be installed, then install the drive, convenient assembly site, little space occupation, valve flow through size and other characteristics.