Pipe fittings play an important role in the connection, controlling, direction changing, streaming components collectively sealed and supporting. Carbon steel pipe fittings are main auxiliary products for the steel pipe. The key products are carbon steel elbow, flanges, steel cap, steel tee, carbon steel pipe reducer. The standards include national standard, American standard and DIN.

Carbon steel pipe fittings also called pressure pipe fittings. It is usually divided into three types: butt class pipe fittings, socket welded pipe fittings and threaded pipe fittings. In pipe joints system, you need various sizes of steel pipe fittings due to the different pipe sizes. For example, the threaded pipe fitting is necessary for straight tube or tube section connecting. Because of the double characteristics of the tubes and mechanical elements, all pipe should belongs to the steel pipe fittings after finished the deep process of steel pipe.

The sides of the steel pipe are painted to guaranteed as the fittings or oxidation resistant metal like zinc or nickel with electroplating. But it is well-known that the out layer of steel tube is just a thin film that is easy to be damaged. Once the protective layer damaged, the steel tubes start to rust in the atmosphere. So the preservative is necessary for the carbon steel tube depending on the zinc, nickel and chromium as protective layer.