1. Cleaning:

First, clean the surface of the electric heating tube, remove impurities, and ensure the clean and clean surface of the electric heat pipe.

2. Defatting:

Immerse the electrical heating tube into the PH value of about 13 degree-free night for 30 minutes. After the time, heat the water to remove the impurities produced by the chemical reaction on the surface to ensure the surface cleaning.

3. Pickling:

After degreasing treatment, the electric heating tube is placed in the PH value of 3 acidic solution for 10 minutes, and then the electric heating tube is cleaned with water.

4. Black processing:

Ensure that the PH value of the liquid is 2-4, and the processing time is about 10 minutes. After processing, the surface of the heating tube is cleaned.

5. Drying oil:

After finishing the surface chemical treatment and cleaning of the electric heat pipe, the surface should be dried and removed. After drying, the electric heating tube shall be oily.

A layer of oxide film is produced on the surface of the heating tube after dark treatment, and the oxidation film has a good corrosion resistance and protective effect on the heating tube.