Socket welds form fillet welds, while butt welds form butt welds. It is better to analyze the butt joints from the strength and stress state of the welds than the sockets. Therefore, in the case of high-pressure grades and occasions with poor service conditions, the form of docking should be adopted.

Socket welding is generally used for small diameters of DN40 or less, which is economical. Butt welding is generally used for DN40 or above. The form of socket welding is mainly used for small diameter valves and pipe, pipe fittings and pipe welding. Small-diameter pipes generally have a thin wall thickness, are easy to be misaligned and ablated, and are difficult to weld, and are more suitable for socket welding. In addition, the socket of the socket welding has a reinforcing effect, so it is also used under high pressure. However, socket welding also has shortcomings. One is that the stress condition after welding is not good, the welding is not welded, and there is a gap inside the pipe system. Therefore, the pipe system used for crevice corrosion sensitive media and the pipeline system with high cleaning requirements is not suitable. Use socket welding. Furthermore, for ultra-high pressure pipes, even small-diameter pipes have a large wall thickness, and it is possible to avoid socket welding by using butt welding.

The former must be one big and one small in diameter before it can be inserted into the weld.

#1 The latter diameters may be the same or different.

#2 The welding groove is different in form.

#3 The welding process is different. The strength after welding is different.

Most of the lower pressure grades are smaller socket welds, and the higher pressure grades are often butt welds. Butt welds are 100% tested for flaw detection to ensure no leaks.

As the name suggests, socket welding is to insert the tube into the welding, but the butt welding is directly welded to the nozzle. Generally, the requirements for butt welding are higher than those for socket welding, and the quality after welding is good, but the detection method is relatively strict. For the welding to do the radiographic inspection, the socket welding can be used for magnetic powder or penetration testing (like carbon steel for magnetic powder, stainless steel for penetration). If the fluid in the pipeline does not require high welding, it is recommended to use socket welding for easy inspection.