What are the specific steps for welding and sealing in the insulation layer of a straight stainless steel electric heating coil?

The specific steps for welding and sealing in the insulation layer of the straight-tube stainless steel electric heating ring are as follows:
Preparation
Material and tool preparation: Prepare stainless steel sheets that match the material of the electric heating ring, generally with a thickness of about 0.5-1.0mm, and corresponding welding materials, such as stainless steel electrodes or welding wires. At the same time, prepare welding equipment, such as argon arc welding machines, electric welders, etc., and ensure that the equipment is in good condition.
Cleaning treatment: Clean the surface of the straight-tube stainless steel electric heating ring and the surface of the stainless steel sheet to be welded, and remove impurities such as oil, dust, rust, etc. to ensure the quality of welding. You can use tools such as sandpaper and wire brushes for grinding, and then wipe it clean with a clean cloth.
Insulation layer installation: First, wrap the insulation materials such as glass fiber wool evenly on the electric heating ring, and use fixings (such as metal wire, high-temperature resistant tape, etc.) to initially fix it to ensure that the surface of the insulation layer is flat and there are no obvious bumps or gaps.
Welding operation
Installation and fixation of thin plate: Wrap the prepared stainless steel thin plate around the insulation layer so that it fits tightly with the surface of the electric heating ring. For longer straight-tube electric heating rings, the thin plate can be installed in several sections and then welded together. During the installation process, use a clamp or spot welding to temporarily fix the thin plate on the electric heating ring to prevent it from moving during welding.
Welding parameter setting: Adjust the parameters of the welding equipment according to the thickness of the stainless steel thin plate and the material of the electric heating ring. For argon arc welding, the current is generally between 80-120A and the voltage is around 12-15V; for electric welding machines, the current can be selected according to the diameter of the electrode, generally between 100-150A. The welding speed should be moderate to ensure that the weld is uniform and full.
Start welding: Start from one end of the electric heating ring and weld along the circumference. When welding, keep the welding gun or welding rod at an appropriate angle to the welding surface (generally 70° - 80°), and move the welding gun or welding rod steadily according to the set welding parameters so that the weld evenly covers the connection between the thin plate and the electric heating ring. For the butt joints of thin plates, use appropriate welding methods, such as butt welding or lap welding, to ensure that the weld is firm and sealed. During the welding process, pay attention to the formation of the weld and adjust the welding parameters in time to avoid welding defects such as pores, slag inclusions, and cracks.
Weld inspection and repair: After completing a circle of welding, immediately inspect the weld to check for problems such as incomplete penetration, leaking welds, and pores. If problems are found, repair them in time. For smaller pores or defects, argon arc welding can be used for repair welding; for larger problems, it may be necessary to grind off the defective parts and re-weld.
Subsequent treatment
Weld grinding: After welding, use grinding tools (such as angle grinders, sandpaper, etc.) to grind the weld to make its surface smooth and flat, which can not only improve the appearance quality, but also reduce the possibility of heat accumulation and impurity adhesion.
Cleaning and protection: Clean the welding slag, spatter, etc. generated during the welding process, and then clean the entire electric heating coil and insulation layer. In order to prevent the stainless steel sheet from rusting, a layer of anti-rust oil can be applied or passivation treatment can be performed as needed.
Final inspection: Conduct a comprehensive inspection of the insulation layer after welding and sealing, including sealing inspection (which can be done by pressure testing and other methods), insulation effect inspection, etc., to ensure that it meets the use requirements.