What is the difference between butt welding flange and flat welding flange

The butt welding steel flange is that the pipe diameter and wall thickness of the interface end is the same as the pipes to  be welded, and are welded like two pipes. The flat welding steel flange is a concave table that is slightly larger than the  outer diameter of the pipe at the interface, and the pipe is inserted and welded inside. Butt welding has better  welding performance and less corrosion.

Flat welding and butt welding are the welding methods when steel flanges and pipes are connected. When welding flat welding steel flanges, only single-sided welding is required, and there is no need to weld the inner port of the pipe and steel flange  connection. The welding installation of butt welding steel flanges requires double steel flanges. face welding. Therefore, flat  welding steel flanges are generally used for low and medium-pressure pipelines, and butt welding steel flanges are used for the  connection of medium and high-pressure pipelines. Butt welding steel flanges are generally at least PN2.5MPa. Butt welding  is used to reduce stress concentration. Butt welding steel flanges are mostly neck steel flanges, also called nipple steel flanges.  Therefore, the installation cost, labor cost, and auxiliary material cost of the butt welding steel flange are higher,  because there is one more process.

Not all butt welding steel flanges need to be welded on both sides of the inner and outer sides. If there are no special  requirements, generally only one outer welding is required. Haven't seen 1/2" butt welding steel flanges :), flat welding  is better for welding Well because the pipe and the steel flange are perfectly vertical, the pipe will not be skewed.