Malleable cast iron pipe fittings refer to pipe connection components made of malleable cast iron (commonly known as malleable steel) Malleable cast iron is obtained by casting white cast iron and then undergoing a process of annealing and malleability treatment, which decomposes cementite into flake-likeite, thus obtaining better mechanical properties. Malleable steel pipe fittings are widely used in pipeline connections due to their good plasticity and toughness. Common malleable steel fittings include elbows, tees, pipe clamps, nipples, unions, bushings, caps, flanges, four-ways, reducers, bends, thread elbows, long speed adapters, short speed adapters, rigid joints, flexible joints, etc. These fittings are mainly used to connect steel pipes with the same nominal diameter allowing the pipeline to be connected with bolts and having the advantage of being separable, which facilitates the installation and maintenance of the pipeline.