Sealing treatment of high-temperature resistant electric heating tubes

Sealing treatment of high-temperature resistant electric heating tubes

The structure of electric heating tubes is mostly filled with magnesium oxide powder as an insulation layer and thermal conductive medium between the electric heating wire and the heat transfer metal tube. Due to the strong moisture absorption of magnesium oxide powder, the insulation resistance will quickly decrease. Therefore, the end of the electric heating tube must be sealed to prevent the entry of humid air. Normally, silicone or epoxy resin is used for sealing, but this material fails at 200 degrees Celsius. For high-temperature electric heating tubes, glass sealing is generally used.

Place glass preforms of appropriate size into the electric heating tube, heat them up to a certain temperature using heating equipment (flame nozzle, high-frequency heating machine, box furnace), and the glass begins to soften and flow to fill the gaps. After cooling to room temperature, the glass solidifies and completes the sealing process.

The production of electric heating tubes requires many processes, and every detail should be taken seriously. Details determine success or failure, especially in welding. If it is a virtual welding, it cannot be detected during inspection, and there is no difference in the initial use by customers. Over time, the welding points may break. For this reason, we have provided training to all welding workers, emphasizing a sense of responsibility. No matter how busy they are, every branch pipe must be welded in place, and after each welding, inspections must be carried out to ensure a 100% pass rate.