Welding process

Required equipment

One set of manual welding equipment, one handle angle grinder, one electric air hammer and one flat ruler.

Preparation before welding

1. Check the commissioning equipment to ensure that the equipment is operating normally; 2. Prepare the φ4.0J402 electrode is best dried at 300 ℃-350 ℃ for one hour.

Welding process

1. Assembly Assemble the vertebral body and the large flange according to the drawings, and divide the large flange into 8 equal parts on average. 2. Welding Because the flange is thicker and the groove is larger, segmental symmetry and multi-layer welding are used.

Welding quality

Requires that the strength of the weld reaches at least the strength of the base metal. The surface of the welding seam is smooth and smooth, without defects such as burn-through, air holes, welding leakage, slag inclusion, undercut, under-welding etc. The height is less than 2mm.

  Precautions

1. Be sure to use J506 electrode for manual surfacing and low current welding when making the primer. Welding strictly in accordance with the welding process. 2. After each welding position, use a ruler to clamp the deformation of the flange plane. 3. While welding, hit the weld with an air hammer to eliminate stress.

Flange gasket

Gasket is a ring made of material that can produce plastic deformation and has a certain strength. Most of the gaskets are cut from non-metallic plates, or made by professional factories in accordance with the prescribed size. The materials are asbestos rubber plates, asbestos plates, PTFE plates, polyethylene plates, etc .; also thin metal plates (tinplate, Stainless steel) a metal-clad gasket made of asbestos and other non-metallic materials; there is also a spiral wound gasket made of thin steel tape and asbestos tape. The most commonly used is a stainless steel tape and graphite. As for the metal spiral wound gasket, asbestos can also be used for the spiral wound belt according to the environment. Ordinary rubber gaskets are suitable for occasions where the temperature is below 120 ℃; asbestos rubber gaskets are suitable for occasions where the water vapor temperature is lower than 450 ℃, the oil temperature is lower than 350 ℃, and the pressure is lower than 5MPa. The medium, the most commonly used is acid-resistant asbestos board. In high-pressure equipment and pipelines, metal gaskets of lens type or other shapes made of copper, aluminum, No. 10 steel, and stainless steel are used. The contact width between the high-pressure gasket and the sealing surface is very narrow (line contact), and the processing finish of the sealing surface and the gasket is high.

Low-pressure small-diameter wire-connected flanges, high-pressure and low-pressure large diameters use welding flanges, the thickness of flanges with different pressures and the diameter and number of connecting bolts are different.