Butt welding and socket welding of valves

In the pipeline system, welding is often used between valve and valve, between valve and pipe, and the most commonly used is butt welding and socket welding. As the name suggests, socket welding is to insert the pipe into the welding, butt welding is directly relative to the pipe orifice.

The difference between butt welding and socket welding is as follows:

1. Socket welding forms fillet weld and butt weld forms butt weld. According to the analysis of the strength and stress condition of the weld, the butt joint is better than the socket, so it is appropriate to adopt the butt joint form in the high pressure level occasions and the field with bad service conditions.

2. Socket welding is generally used for small diameter less than or equal to Dn40, which is more economical. Butt welding is generally used for Dn40 and above. The connection form of socket welding is mainly used for welding of small diameter valves and pipes, pipe fittings and pipes. Generally, the wall thickness of small diameter pipe is thin, which is easy to be staggered and ablated, so it is difficult to butt weld, so it is suitable for socket welding. In addition, the socket weld has the role of reinforcement, so it is also used under high pressure. However, socket welding also has disadvantages. One is that the stress condition after welding is not good, which is prone to incomplete welding, and there is a gap in the pipe system. Therefore, socket welding is not suitable for the pipeline system used for crevice corrosion sensitive medium and pipeline system with high cleaning requirements. Moreover, the wall thickness of ultra-high pressure pipeline, even if the pipe with small diameter is also very large, socket welding can be avoided as far as possible if butt welding can be used.

3. The diameter of socket welding must be one large and one small before inserting welding. The diameter of butt welding can be the same or different.

4. Most of the lower pressure level and smaller diameter are socket welding, while the higher pressure level is usually butt welding. 100% flaw detection test is required for butt welding to ensure no leakage.

5. Generally, the requirement of butt welding is higher than that of socket welding, and the quality after welding is good, but the detection method is relatively strict. For butt welding, radiographic inspection is required, and magnetic particle or penetrant testing is enough for socket welding (for example, magnetic powder for carbon steel and penetration test for stainless steel). If the fluid in the pipeline does not require high welding, it is recommended to use socket welding, which is convenient for detection.

TONY is specialized in the production and sales of stainless steel high-pressure ball valve, needle valve and check valve, and provides the connection methods of ferrule, thread, welding (butt welding and socket welding), flange, tri clamp, quick coupling, etc.