Large elbow _ Hebei billion pipeline _ large bending thick gold provided by Hebei million gold piping. Large elbow | Hebei billion gold piping | Large elbow manufacturer Hebei million gold Pipe Manufacturing Co. (www.yijinguanjian.com) 2013 has been newly upgraded launched since the major construction projects in the pipe industry, the elbow have had to bear its most important role. Bending role can not be ignored. Meanwhile, other areas of the country in the construction of medium and large thick-walled bends, bends also assume a crucial role. Bend in the petrochemical, coal chemical, electric power industry, metallurgical industry, oil gas and other fields have important applications, and demand was growing rapidly. Our pipe fittings industry has maintained rapid growth, expanding industry, continued strong demand for large pipe fittings elbow, the application of advanced equipment and technology is an important driving force. Therefore Large elbow professional large-caliber, China should continue to increase investment in technology elbow, elbow and timely technical innovation and technology to make the elbow does not become a bottleneck in the development of various industries. And to meet domestic demand, based on efforts to open international markets to become the world's leading exporter of bending and bending technology. I plant to improve the quality of pipe bending precision as a starting point, analyzes the rotary tube bending traction generated during the rebound phenomenon, elongation phenomenon. Through theoretical analysis derived approximate calculation formula, and by a large number of tests conducted on certain amendments to the theoretical formula to finalize the fixture, the impact bending mode of the curved shape of the large pipe elbows and cheap, to identify different specifications, different thickness, different elastic deformation and plastic deformation of the material of the pipe, tube bending before the angle and length compensation, no margin achieved tube bending.