Applications of flat welding flanges：

Flat Welding Flanges features a simple structure and easy fabrication. Its stress-bearing performance falls between that of integral flange and lap joint flange. When used on pressure vessels, flat welding flanges are further classified into Type A Flat Welding Flanges and Flat Welding Flanges.

Flat Welding Flanges applied to pressure vessels are divided into two categories:

① Type A Flat Welding Flanges is directly welded to the vessel. Its weld seam has a small size or is welded without groove preparation, which cannot ensure the flange and the vessel bear the load synchronously. The strength calculation of this type of flange shall refer to the standard for lap joint flange.

② Type B Flat Welding Flanges is generally attached with a section of thickened short cylinder. The welding quality between the flange and the short cylinder is reliable, which can ensure the flange and the vessel bear the load synchronously. Its strength calculation can be carried out in accordance with the standard for integral flange. Type B flat welding flanges is widely used for the connection of medium and low-pressure vessels and pipelines.

Advantages and Disadvantages of the Two Types：

Type B flange is equipped with a short cylinder, so it has better rigidity than Type A flange and can be applied to occasions with higher pressure and larger diameter. Type A flange adopts a V-shaped groove while Type B flange uses a U-shaped groove. Therefore, Type B flange is easier to achieve full penetration welding, resulting in higher strength and rigidity.