Large flanges are also called reel flanges, spliced flanges, large diameter flanges, wind flanges. So-called large flange is beyond the size of the flange stipulated in the relevant state departments, generally refers to DN2000 above the size of the flange, such the flanges are made to provide drawings to production, quality process of large flange forging and rolling two kinds, material has stainless steel, carbon steel and alloy steel.

Large flange threaded connection (wire) flange and welding flange. The low pressure small diameter has the silk grafting flange, the high pressure and the low pressure large diameter are the welding flange, the thickness of the flange of different pressure and the connection bolt diameter and the number are different.

Large flanges are widely used as seals and fastening fittings in large containers in aerospace, petroleum, chemical and other fields. Despite the processing ability of the subject, for large flange, due to its size is too big, due to transportation reasons, only makes the whole processing of large flange is impossible, must be split processing. Normally, large flanges are divided into sections for processing. First of all, the blank forging square billet, then cold bending into a segment, after annealing heat treatment to stress, Mosaic full circle stands on the processing to the design of shapes and sizes and shipped to the construction site, after again the number segment compound into a complete flange and compound with pressure vessel.

Large flange connection is easy to use, can withstand greater pressure, play an important role and value in use. In industrial pipelines, large flange connections are widely used and have different meanings and functions in industry. In the family, the pipe diameter is small, and is low pressure, see no flange connection. If in a boiler room or production site, there are large flanged pipes and equipment.

There are many factors influencing the service life of large flange, because of the large flange material viscosity is higher, chip breaking performance is poor, so in the process of the large flange with tap tapping prone to chip scratch artifacts thread or tap the phenomenon such as collapse edge, affect the efficiency and the quality of thread. In order to prolong the service life of tap, improve the quality of screw thread processing, in the mill, large flange on the whole length of the thermal mechanical historical changes obviously, especially in the micro produce large flange, will strongly affect the finishing mill on the degree of recrystallization and grain growth and precipitation, and causes the whole function of large flange length on the microstructure and radical changes. It is necessary to maintain the original geometry of the front guide department, so that the grinding machine can be used for grinding. A good way to solve the tapered surface is to customize the short tap of the base surface according to the specific requirements of the processed threads.