The large flange design and manufacturing is composed of two interlocking base plates at 90 degrees, two flange support plates, two upright plates, and four reinforcing rib plates. To ensure rigidity, the welding seams between adjacent plates should be beveled and fully penetrated, with weld angles of 20-30mm. Bolt holes are drilled on the flange support plates to ensure accurate connection between the flange and the support plate. The back of the small-end flange has a gap that can accommodate a small manual jack. Additionally, notches are cut along the upright plate direction on the flange support plate to allow the elbow to fit into the fixture. The fixture, made from thicker steel plates in an approximately channel-like structure, meets the rigidity requirements during cutting. The two flange surfaces of the large flange are perpendicular to each other, while the lathe's worktable rotates horizontally. Therefore, the primary function of this fixture is to connect the fixture to the flange using the bolt holes on the large end flange. When the fixture is mounted on the worktable, the flange to be machined should be concentric and parallel to the lathe's worktable.

During the flange processing, it is crucial to understand that certain components may inherently have defects during the welding process. In the case of stainless steel flange welding defects, if they are severe, they are typically addressed through manual mechanical polishing. This method, while effective for remediation, can leave a series of polishing marks, which may result in an uneven surface finish, directly affecting the overall appearance of the equipment. Flange processing may result in uneven polishing, which can make it challenging to achieve a uniform treatment effect during the subsequent acid washing and passivation processes, especially for larger workpieces. If this uniformity cannot be achieved, it will undoubtedly require more time during the processing, and relatively speaking, it will also consume a significant amount of auxiliary materials. Another issue is also encountered during the processing.

Potential scratches on the flange may be difficult to remove, leading to a series of chemical corrosion under conditions of corrosive media during the overall passivation process, which can result in rust. To reduce the number of fixtures, this fixture should be able to change the clamping position, ensuring that both ends of the elbow can be processed on a single fixture. Additionally, the fixture must have sufficient rigidity to avoid severely affecting the quality of the flange sealing groove. Therefore, under normal use conditions, the height of the fixture should be minimized to enhance rigidity and facilitate operation. After the fixture is fixed with the large flange, the rotating radius should not exceed the lathe's working radius, and it should be easy to clamp and adjust, as well as convenient for feeding and cutting. The cantilever beam with a槽type structure experiences bending and torsion when subjected to force during turning, and its deflection and angular displacement should be verified. Through the above verification, the large deflection of 7.27×10-7m and the large angular displacement of 8.969×10-5 are within the allowable deformation. Reinforcing ribs have been added to the relevant areas, resulting in rigidity far exceeding the calculated values. The rigidity fully meets the requirements of the cutting force. The combined fixture with the elbow flange has a large turning diameter of 2.42m, which is less than 3.50m (the turning diameter of a double-column lathe).