Carbon steel fittings，It is the most widely used pipe product. The main materials are q235 20, 35, 45, 16mn. The main products include carbon steel elbows, carbon steel flanges, carbon steel tees, carbon steel tees, carbon steel diameter tubes (size heads), carbon steel caps (tube caps) and so on. The main implementation standards include national standards, U.S. standards, daily standards, etc., and its Chinese standards also include the Ministry of Chemical Industry standards, Sinopec pipe standards, power pipe standards. Steel pipe elbow in the pipeline system, elbow is a pipe fittings to change the direction of the pipeline. Carbon eccentric reducer It is a kind of pipe fitting used in pipe reducing. The commonly used forming process is reducing pressing, expanding pressing or reducing plus expanding pressing, and stamping can also be used for some specifications of reducing pipes. Carbon steel tee is also a kind of pipe fitting, generally there are two kinds.The straight tee pipe fitting is the same diameter at both ends, and the branch pipe with two different diameters is called reducing tee. Carbon steel seamless steel pipe is a kind of long steel. The steel pipe has a hollow section, which is widely used as a pipeline for conveying fluid, such as oil, natural gas, gas, water and some solid materials. It is an economic section steel, widely used in manufacturing structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and steel scaffold used in construction.