Socket welding and butt welding are common welding connection forms of flange and pipe. Socket welding is to insert the pipe into the flange and then weld, while butt welding is to butt weld the pipe and the butt surface. The socket weld of the socket welding flange cannot be subject to radiographic inspection, but the butt welding flange can. Therefore, the butt welding flange is generally used for those with higher requirements for butt weld inspection.
Generally speaking, butt-welding flange has higher requirements for manufacturing and better welding quality than socket welding flange. However, the inspection method for butt-welding flange is relatively strict, and radiographic inspection is required for it, while the acceptance welding flange only needs penetrant inspection. Therefore, socket welding flange can also be used if the fluid in the pipeline does not require high welding grade.
Socket-welded flanges can be used for pipes with low pressure rating and small diameter, but the post-weld stress of the socket-welded flange is not good, and it is easy to have incomplete penetration, resulting in cracks in the pipe. Therefore, the socket-welded flange cannot be used for pipes that are prone to corrosion or have high requirements for cleanliness. Or in high-pressure pipeline, socket welding flange cannot be used no matter how small the diameter is, so it is recommended to use butt welding flange in working environment with high pressure rating and poor service conditions.
The diameter of socket welding flange is generally one big and one small, while the diameter of butt welding flange can be the same or different. The socket welding flange will not have the problem of beveling and butt misalignment, and the welding position can be changed to flat welding.
Generally, the socket welding flange is used for pipes less than 2 inches. The socket welding flange is mainly used for small diameter pipe fittings. This kind of pipe has thin wall thickness and is prone to misalignment and corrosion, so it is more suitable for socket welding flange. Butt-welding flanges are more often used for pipes above 2 inches, because the pressure resistance of butt-welding flanges is better than that of receiving welding flanges.
Post time: Jan-12-2023
