The expansion coefficient of quartz tube is small, and it will not burst when placed in water immediately after heating. So, in the heating tubes used in heating equipment, in order to directly radiate the heat emitted by the middle electric heating wire after being electrified, there is a type of milky white quartz tube that can radiate the heat emitted by the electric heating wire. Therefore, milky white quartz tubes are used as electric heating tubes because they are milky white, and the electric heating wire inside is not easy to see. In fact, there is an electric heating wire. Transparent quartz tubes have a characteristic of being able to transmit ultraviolet light, and many good ultraviolet sterilization lamps are made of transparent quartz tubes.