A 180° elbow is a metal pipe fitting used to change the direction of piping in carbon steel pipelines.
A 180° elbow is a metal pipe fitting used to change the direction of piping in carbon steel pipelines.
A 180° elbow is a metal pipe fitting used to change the direction of piping in carbon steel pipelines. It can be connected via threaded or welded joints. Commonly available angles include 45°, 90°, and 180° elbows, though custom designs such as 60° elbows are also manufactured to meet specific project requirements. Elbows are made from a variety of materials, including cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, non-ferrous metals, and even plastics. Connection methods for these fittings include direct welding (the most common approach), flange connections, hot-melt bonding, electrofusion welding, threaded connections, and socket-type connections. Based on manufacturing processes, elbows can be categorized into types such as welded elbows, stamped elbows, push-bend elbows, and cast elbows. Other common names for this fitting include "90-degree elbow," "right-angle bend," and "Elbow Aier."
180° elbows are first classified based on their radius of curvature, which can be either long-radius or short-radius elbows. A long-radius elbow has a curvature radius equal to 1.5 times the pipe’s outer diameter, expressed as R = 1.5D. In contrast, a short-radius elbow features a curvature radius that matches the pipe’s outer diameter, or R = 1.0D. (Here, D represents the elbow’s diameter, while R stands for the radius of curvature; D can also be indicated in multiples.) When categorized by pressure rating, there are roughly seventeen standard types, corresponding exactly to U.S. pipe standards. These include: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, Sch100, Sch120, Sch140, Sch160, and XXS. Among these, STD and XS are the most commonly used. Elbows can also be classified according to their angle, with options including 45°, 90°, and 180° bends. The manufacturing standards followed for these fittings include GB/T12459-2005, GB/T13401-2005, GB/T10752-1995, HG/T21635-1987, and D-GD0219, among others.
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