Steel Plate Inspection: Ultrasonic testing of raw materials must be conducted prior to production to ensure there are no issues before they can enter the production line.

2. Material Cutting: Utilizing gas cutting or plasma to achieve the required dimensions, with additional operations such as beveling the edges.

3. Pre-bending: Choose a pre-bending machine or a press based on the thickness of the steel plate for pre-bending.

4. Shaping: On the forming machine, first, half of the pre-bent steel plate is subjected to multiple rolls to become "J"-shaped. Then, the other half of the steel plate is processed in the same manner, forming it into a "C" shape, ultimately creating an open "O" shape.

5. Pre-welding: We typically use flux-cored welding for pre-welding.

6. Inner Welding: Utilizing longitudinal multi-wire submerged arc welding on the inner side of large-diameter pipe manufacturing plants.

7. Welding: Employing longitudinal multi-wire submerged arc welding on steel plate coils for welding.