Welding flanges are resistant to deformation, provide good sealing, and have a wide range of applications. They meet the requirements for both rigidity and elasticity and feature a reasonable welding thinning transition. The weld joint is spaced far from the mating surface, ensuring the mating surface is not deformed by welding temperatures. They adopt a more complex trumpet-shaped structure, suitable for pipelines experiencing significant fluctuations in pressure or temperature, as well as for high-temperature, high-pressure, and low-temperature pipelines. Typically used for pipe connections and valves with PN over 2.5 MPa; also for pipelines transporting expensive, flammable, or explosive media.