22. Discharge pneumatic ball valve: the discharge pneumatic ball valve is a valve that uses a ball with a circular channel as the opening and closing part. The ball rotates with the valve stem to achieve the opening and closing action. The opening and closing part is a ball with holes, which rotates around the axis perpendicular to the channel to achieve the purpose of opening and closing the channel. It is suitable for sulfuric acid, hydrofluoric acid, phosphoric acid, chlorine, strong alkali, aqua regia and other highly corrosive media. 　　

2.2 The function of the handheld operator is to search the slave Bluetooth, and after the master slave Bluetooth establishes a link, operate the valve pneumatic device, and synchronously display the screen content of the valve pneumatic device. Its system structure takes 8-bit AVR microcontroller ATmega128L as the core, including keys, LCD, main Bluetooth module and power processing. The KC02 main Bluetooth module is connected to the MCU through the serial port. The handheld operator uses batteries to power the entire embedded system after voltage stabilization through the power conversion chip AMSI1117.