The long and high neck butt welding flange replaces the short joint in the Japanese flat welding flange with the root stiffening, thus increasing the overall stiffness of the flange more effectively. Meanwhile, the flange and the equipment adopt butt welding connection, so higher pressure range (PN0.6mpa ~ 6.4mpa) and diameter range (DN300mm ~ 2000mm) are used, and the applicable temperature range is -20℃ ~ 450℃.