American Standard ASME B16.9 Carbon Steel Pipe Fitting Elbow Pipe Fittings Elbow

Carbon steel elbows are metal fittings that change the direction of the pipeline on carbon steel pipes. The connection methods are threaded and welded. According to the angle, there are three most commonly used ones: 45° and 90°180°. In addition, it also includes other abnormal angle elbows such as 60° according to engineering needs. The elbow materials are cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, non-ferrous metals and plastics. The ways to connect with the pipe are: direct welding (the most common way) flange connection, hot melt connection, electrofusion connection, threaded connection and socket connection. According to the production process, it can be divided into: welding elbow, stamping elbow, push elbow, casting elbow, etc. Other names: 90 degree elbow, right angle bend, love and bend, etc.

Variety classification

Carbon steel elbows are first classified according to their radius of curvature, which can be divided into long radius elbows and short radius elbows. Long-radius elbow refers to its radius of curvature equal to 1.5 times the outer diameter of the tube, that is, R=1.5D. A short radius elbow means that its radius of curvature is equal to the outer diameter of the pipe, that is, R=1.0D. (D is the diameter of the elbow, R is the radius of curvature. D can also be expressed in multiples.) If divided by pressure level, there are about seventeen types, which are the same as the American pipe standards, including: Sch5s, Sch10s, Sch10 , Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, Sch100, Sch120, Sch140, Sch160, XXS, among which the most commonly used are STD and XS. According to the angle of the elbow, there are 45° elbow, 90° elbow and 180° elbow. The implementation standards are GB/T12459-2005, GB/T13401-2005, GB/T10752-1995, HG/T21635-1987, D-GD0219, etc.

The advantages of the carbon steel elbow manufacturing process are mainly manifested in the following aspects

(1) No tube blank is required as raw material, which can save the cost of tube making equipment and molds, and can obtain arbitrarily large diameter and relatively thin carbon steel elbows.

(2) The blank is a flat plate or a developable curved surface, so the blanking is simple, the accuracy is easy to ensure, and the assembly and welding are convenient.

(3) Due to the above two reasons, the manufacturing cycle can be shortened, and the production cost is greatly reduced. Because it does not require any special equipment, it is especially suitable for on-site processing of large carbon steel elbows.

(4) Carbon steel elbows are suitable for pipeline series in oil, natural gas, chemical, hydropower, construction and boiler industries.