Butt welding flange is that the diameter and wall thickness of the interface end are the same as that of the pipe to be welded, and then welded as two pipes. The flat welding flange is a concave platform with the inner hole slightly larger than the outer diameter of the pipe, and the pipe is inserted for welding. Flat welding and butt welding refer to the welding method when flange and pipe are connected. When welding flat welding flange, only one side welding is needed, and the inner opening of pipe and flange connection is not required.
The welding and installation of butt welding flange requires double side welding of flange. Therefore, the flat welding flange is generally used for low and medium pressure pipeline, and the butt welding flange is used for the connection of medium and high pressure pipeline. The butt welding flange is generally at least used to reduce the stress concentration. The general butt welding flange is mostly neck flange, also known as high neck flange. Therefore, the installation cost of butt welding flange, labor cost and auxiliary material cost should be high, because there is one more process.
Butt welded fitting is a kind of pipe fittings manufactured by pipe welded. For pipe fittings manufacturers, welded pipe forming process and seamless pipe forming prcocess is basically same.The forming process of butt welded fittings does not include welding process; the other is the pipe fittings manufacturers finish the welding process that forming required. Butt welded fittings can be divided into carbon steel butt welded fittings and stainless steel butt welded fittings.
