Socket Weld Flanges and How They Are Welded?

Basic product explanation:

Socket welding flange is a flange with one end welded to the steel pipe and the other end bolted.

Sealing surface forms include raised face (RF), concave convex face (MFM), tenon and groove face (TG) and joint face (RJ)

Materials are divided into:

1. Carbon Steel: ASTM A105, 20 #, Q235, 16Mn, ASTM A350 LF1, LF2CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70;

2. Stainess Steel: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;

Manufacturing standards:

ANSI B16.5, HG20619-1997-GB/T9117.1-2000-GB/T9117.4-200, HG20597-1997, etc

Connection mode:

flange nut, bolt connection

Production process:

professional overall forging, forging manufacturing, etc

Processing method:

high-precision CNC lathe turning, ordinary lathe fine turning, argon arc welding and other processing.

Application scope:

boiler, pressure vessel, petroleum, chemical industry, shipbuilding, pharmacy, metallurgy, machinery, stamping elbow food and other industries.

Commonly used in pipes with PN ≤ 10.0MPa and DN ≤ 40.

How are socket flanges welded?

Generally, the pipe is penetrated into the flange for welding by socket welding. Butt welding is to use butt welding flange to butt weld the pipe and the butt face. The socket welded junction cannot be subject to radiographic inspection, but butt welding is OK. Therefore, it is recommended to use butt welding flange for the welding junction with high requirements.

Generally, butt welding requires higher requirements than socket welding, and the quality after welding is also good, but the detection method is relatively strict. Butt welding shall be subject to radiographic inspection, and socket welding shall be subject to magnetic particle or penetrant inspection (such as carbon steel for magnetic particle and stainless steel for penetrant inspection). If the fluid in the pipeline does not have high requirements for welding, socket welding is recommended for convenient detection

The connection mode of socket welding is mainly used for welding small diameter valves and pipes, pipe fittings and pipes. Small diameter pipes are generally thin, easy to be staggered and ablated, and difficult to butt weld, so they are more suitable for socket welding. In addition, socket of socket welding has the effect of reinforcement, so it is also used under high pressure. However, socket welding also has disadvantages. One is that the stress after welding is not good, and it is easy to have incomplete welding penetration. There are gaps in the pipe system. Therefore, socket welding is not suitable for pipe systems used for gap corrosion sensitive media and pipe systems with high cleanliness requirements. Moreover, the wall thickness of ultra-high pressure pipes, even small diameter pipes, is also very large, so socket welding should be avoided if butt welding can be used.

In short, socket welds are fillet welds and butt welds are butt welds. According to the strength and stress condition of the weld, the butt joint is superior to the socket joint, so the butt joint should be used in the situation with high pressure level and in the field with poor application conditions.

Pipe flange welding includes flat welding, butt welding and slip welding.


Post time: Nov-29-2022