Socket welding(SW) and butt welding(BW)

Socket welding generally insert pipe into flanges for welding, butt welding uses butt welding flange to welding pipe and butt face, socket weld radiography is not possible, butt welding can, so for weld testing requirements highly recommended butt welding flange. General Butt demanding requirements than socket welding, welding quality stuff, but relatively strict testing means. Butt do ray testing, magnetic particle or socket weld penetration testing done on it (like a powder made of carbon steel, stainless steel, do penetrate). If the fluid inside the pipe welding less demanding, it is recommended to use socket weld, convenient detection.

Socket welding connections form is mainly used for small diameter valves and pipes, pipe fittings and pipe welding. Small diameter pipes generally thinner wall thickness, easy to wrong side and ablative, butt more difficult, more suitable for socket welding. In addition there socket socket weld reinforcement effect, so there are also many used under high pressure. But there are disadvantages socket weld, a post-weld stress is not good, prone to incomplete penetration welding conditions, piping inside the gap left so sensitive media for crevice corrosion pipeline system and clean piping system should not be demanding with socket weld. Furthermore, high pressure pipes, even small diameter pipe wall thickness is also great, and I can try to avoid butt socket weld connections. 

In short, socket welding fillet is formed, and butt welding is formed by butt weld. From the strength of the weld, such as analysis of the situation by force superior to docking socket, so the pressure rating of the occasion, the use of poor condition of the occasion should be adopted in the form of docking.