Process treatment before sealing of glass sealing process of electric heating tube

(1) Cut the magnesium oxide powder at both ends of the heating tube to a depth of about 8mm.

(2) Clean the inner surface of the tube and the lead rod without leaving MgO powder and dirt.

(3) Put the above-mentioned electric heating tube into an oven at 200℃ to remove moisture, so that the insulation resistance is greater than 10kMΩ.