Firstly, choose a stainless steel tube with proper diameter, thread the resistance wire into the tube, then fill the tube with prepared magnesium oxide powder, heat and bend it to form if necessary, then heat and dry it to dry the water in the tube, weld the resistance wire reliably with the wiring screw at the nozzle, seal the nozzle with heat-resistant sealant, and screw the wiring screw on the screw with insulating porcelain tube. Finally, the high voltage breakdown test is carried out. If it fails, it must not be sold at the factory.

It should be noted that the most important thing is to do a pressure test when heating and molding, drying the water inside, and connecting the resistance wire and the screw.