Flange connection is the two pipes, fittings or devices, each fixed on a flange, between the two flanges, plus flange gasket, fastened together with bolts, completed the connection. Some pipe fittings and devices used to come with flanges, is also classified as flange articulation. Flange connection is an important articulation method for pipeline construction. Flange connection is easy to use, and can withstand greater pressure. In the industrial pipeline, the use of flange connection is very common. In the home, the pipe diameter is small, and is low pressure, can not see the flange connection. If in a boiler room or consumption site, everywhere are flange articulation of pipes and devices.

　　According to the articulation method flange articulation varieties can be divided into: plate flat welding flange, with neck flat welding flange, with neck butt welding flange, socket welding flange, threaded flange, flange cover, with neck butt welding ring loose flange, flat welding ring loose flange, ring groove surface flange and flange cover, large diameter flat flange, large diameter high neck flange, eight blind, butt welding ring loose flange, etc.

　　Required equipment

　　A set of manual electric welding equipment, a handle type angle grinder, an electric air hammer, a plane ruler.

　　Preparation before welding

　　Check the debugging equipment to ensure normal operation of the equipment; 2. Prepare φ4.0J402 welding rod preferably dried at 300℃-350℃ for one hour.

　　Welding process

　　Assembling the vertebrae and large flange together according to the drawing request, and then equally divided the large flange into 8 equal parts. 2. welding because the flange is thicker, the bevel is larger, so the selection of segment symmetry, multi-layer welding.

　　Weld quality

　　Weld strength is required to reach at least the strength of the parent material. Weld appearance smooth and lubricious, no burn-through, porosity, welding leakage, slag, edge biting, not welded full and other defects. The residual height is less than 2mm.