Socket welding pipe fittings include tees, crosses, elbows, etc. There are threads inside the pipe fittings. Socket welding pipe fittings are mainly formed by round steel or steel ingot die-forging blanks, and then processed by a lathe to form a high-pressure pipe connection fitting.
Socket pipe fittings series include three connection types: socket welding connection (SW), butt welding connection (BW), threaded connection (TR). Standard socket fittings ASME B16.11, HG/T 21634-1996, MSS SP-83, MSS SP -79, MSS SP-97, MSS SP-95, GB/T 14383-2008, SH/T3410-96, GD2000, GD87, 40T025-2005, etc., socket welding pipe fittings include stainless steel, alloy steel and carbon steel.
Stainless steel socket welding pipe fittings, as the name suggests, socket welding is to insert the pipe into welding, butt welding is to directly weld with the nozzle. Generally, the requirements for butt welding are higher than those for socket welding, and the quality after welding is also good, but the detection methods are relatively strict. Radiographic flaw detection is required for butt welding, and magnetic particle or penetrant testing for stainless steel socket welded fittings is sufficient (like carbon steel for magnetic powder and stainless steel for penetration). If the fluid in the pipeline does not require high welding, it is recommended to use socket welding, which is convenient for detection.
Stainless steel socket welded pipe fittings are generally used for small pipe diameters less than or equal to DN40, which is more economical. Butt welding is generally used above DN40. The connection form of socket welding is mainly used for welding of small diameter valves and pipes, pipe fittings and pipes. Small-diameter pipes generally have thinner walls, are prone to misalignment and ablation, and are more difficult to weld, so they are more suitable for socket welding. In addition, the socket of socket welding has the function of reinforcement, so it is often used under high pressure. However, socket welding also has disadvantages. One is that the stress condition after welding is not good, and it is easy to cause incomplete welding. There are gaps in the piping system, so the piping system used for crevice corrosion-sensitive media and the piping system with high cleanliness requirements are not suitable. Use socket welding. Furthermore, for ultra-high pressure pipes, even small-diameter pipes have a large wall thickness, so socket welding should be avoided as far as possible if butt welding can be used.