SO flange is an inner hole machined slightly larger than the outside diameter of the pipe, the pipe inserted in the welding.Butt welding flange is the end of the pipe diameter and wall thickness of the same as the pipe to be welded, welding the same as the two pipes.
SO and butt welding refers to the welding method when flange and pipeline connection, welding installation of butt welding flange needs flange welding, the general butt welding flange is more than neck flange also called nipple flange, butt welding flange is generally at least PN2.5mpa, the use of butt welding is to reduce stress concentration.SO flanges require only one side welding and do not need to weld the inner mouth of the pipe and flange connection.So SO flange is generally used for low, medium pressure pipeline, welding flange is used for medium, high pressure pipeline connection, so the installation cost of welding flange, labor cost and auxiliary material cost to be high, because more than one process.
SO flange is a kind of better welding, because the pipe and flange good vertical, the pipe will not skew.Butt welding flange is not all need both sides of the welding, there is no special requirements generally just a welding outside.

SO and socket welding flange, socket welding flange suitable for small diameter, high pressure, high temperature pipe connection way, socket welding is not convex platform, opened a groove in the flange body directly, blind flange to open a hole above, and then a groove, SO a step seal face have the effect of pressure tight seal gasket, and then in pipe welding.
SO is a little better than socket welding.Generally, flat welded flanges are more common and can be used anywhere.Flanges are mainly butt welding, SO, socket welding, lap joint, thread, blind plate, etc. For consumers of welding flanges, only by understanding the production process of flanges can they be operated correctly. Butt welding flanges are used for over 4.0mpa and inflammable, explosive and toxic media, and SO flanges are used for common occasions.
Butt welding flange has the following advantages: health non-toxic, light weight, good heat resistance, corrosion resistance, heat insulation, impact resistance, long service life, welding welding flange assembly is easier to center, installation is simple and convenient;The advantage of SO flange is widely used, can be used in metallurgy, machinery, chemical industry, petroleum, machine tools, water conservancy, construction, engineering, shipping, environmental protection, coal, agricultural machinery, food, boiler pressure vessel and other industries;Beautiful appearance, smooth surface of SO flange, mainly used for carbon steel pipe connection.
Can socket welding flanges also be used at high pressure?The general situation is not selected, if you do penetration detection, it can not be made up.
Butt welding flange and SO flange is commonly used two kinds of flanges, butt welding flange is with neck, and SO flange is not with, if it is a common medium, the pressure is not high, leakage will not cause danger can be considered with SO flange, if for the sake of reliability or choose to use butt welding.The above is to share with you about the difference between SO flange and butt welding flange of the relevant content, hope through the above content, can let you have a further understanding of the difference between SO flange and butt welding flange and understand.