Due to the restriction of valve sealing structure and its corresponding sealing materials, the operating temperature is less than 200 ℃. In addition, the service life is shorter when it is used at 200 ℃ for a long time. Although high-strength graphite material with a short-term resistance of 300 ℃ can be selected for the valve seat, many parts of the valve that need to be sealed still cannot be sealed at high temperature, especially for radial seal, high-strength graphite material is not suitable for radial seal. Generally, the radial seal of insulated pneumatic ball valve adopts O-ring sealing structure, so the service temperature of the whole valve is directly restricted by the service temperature of O-ring. At present, the O-ring used on insulated pneumatic ball valve is fluororubber, but the service temperature of fluororubber is within 200 ℃, and it cannot be used in this extreme temperature for a long time.

2.3 Software process of handheld operator After the handheld operator is reset, first initialize the underlying hardware, and then perform corresponding operations according to the received key commands. In the hardware design, the PD4 of the MCU is connected to the link status port of the Bluetooth module, and the PD7 port is connected to the RESET pin of the Bluetooth module.