Study On Mechanical Properties Of Pressed Loose Steel Pipe Flanges

Flanges are the important parts in the connection of containers and pipes, which ensure the connection integrity and intactness with the bolts and sealing gaskets. In the pipeline project, flanges are mainly used in the connection for pipes, pumps, valves, pressure vessels and pressure devices. It is divided into standard flange and non-standard flange. The non-standard flanges must be calculated to ensure the reliability of its components and the safe operation of equipments, when they are used for pressure vessels and pressure pipes. The current non-standard flange design method is based on GB150-1998 "Steel Pressure Vessel".Pressed loose steel pipe flange (hereinafter to be referred as: pressed flange) is a new kind of non-standard pipe flange for pressure vessels. At abroad, pressure flange has been using in the pressure vessels and pressure pipes whose design pressure is 1MPa, whose design temperature is below 200℃., particularly in the dyeing machine industry has been widespread applied. The plate flange of pressure flange with special-shaped non-planar structure can reduce the wall thickness and the cost of raw materials; the manufacture method is making the flat steel into plate flange for one time, thus can greatly reduce production costs. However, due to GB150-1998 "Steel Pressure Vessel," does not apply to the calculation of pressure flange, so the pressed flange hasn't been applied for engineering applications completely.In this dissertation, the features and structure of pressed flange are introduced; the designing and calculation methods of flange at home and abroad are studied comprehensively. According to the design method of non-standard from GB150-1998"Steel Pressure Vessel", study on mechanical properties of pressed flange, make finite element analysis of pressed flange with software ANSYS, obtain the stress distribution of 11 types of pressed flange; according to the strength failure criterion from GB150-1998"Steel Pressure Vessel", finish the checking of strength. Furthermore, further verify the reliability of strength, stiffness, and leak tightness through the hydraulic test. Finally, in accordance with stress analysis and experimental results, the 2D drawings of pressed flanges are perfected, and we also enact enterprise standards.Research results in this paper provide a complete reference of pressed flange, fully demonstrated the reliability of the pressed flange's structure, establish a theoretical foundation for the application of pressed flange in our countries.