A welding flange, with a neck and a pipe transition and flange connection and pipe butt welding, easy to deformation, good sealing, wide application, rigidity and elasticity of demand and the corresponding reasonable welding thin transition from weld joint surface distance, joint surface from the welding temperature deformation, it take a pair of body structure is more complex, suitable for pressure or temperature fluctuations of the pipeline or high temperature and high pressure and low temperature pipeline, generally used for connecting pipes and valves of PN more than 2.5MPa; also used in pipeline conveying expensive, flammable and explosive medium. Chinese Zhangqiu Mingyuan Machinery Co., Ltd. specializing in the production of GB ship standard, Japanese standard, German standard, American Standard, non - standard, European standard, British standard, professional standard, to meet a variety of harsh conditions, can also provide drawings according to the customer production of flange.