When the pipeline needs to be connected, branched, turned, and reduced in diameter, it needs to be connected with pipe fittings. Commonly used pipe fittings are elbows, tees, reducers and pipe joints. Threaded pipe fittings are divided into two types: galvanized and non-galvanized, and are generally made of malleable iron. Commonly used threaded pipe fittings are: pipe joints are used for the connection of two pipes or with other pipe fittings; reducers (large and small heads) are used to connect two pipes with different diameters; equal diameter and reducing tee, equal diameter It is used for the connection of two pipelines when the planes intersect vertically; the union is used for the pipelines that need to be dismantled frequently; the threaded fittings are mainly used for gas pipelines, heating and water supply and drainage pipelines. In the process pipeline, except for the low-pressure pipeline that needs to be dismantled frequently, it is rarely used on other material pipelines. Stamping seamless elbows are made of high-quality carbon steel, stainless acid-resistant steel and low-alloy steel seamless steel pipes, which are pressed and formed in a special mold. There are 90 degrees and 45 degrees; stamping and welding elbows are made of the same plate material as the pipes and punched into half annular elbows with a die, and then welded together. Usually, the semi-finished products are delivered in pairs, and the welding is carried out according to the welding seam grade of the pipeline during construction. High pressure elbows are forged from high quality carbon steel and low alloy steel. According to the pipe connection form, the two ends of the elbow are processed into threads or grooves, and the processing accuracy is very high.
