Fitting Pipes - Fitting pipes, also known as pipe accessories, connectors, and joint parts. Different types of pipe systems use various fitting pipes to connect pipes, forming pipe steel. 1. Malleable cast iron (malleable iron) fittings are made of malleable cast iron and connected to pipes with threads (threaded). The working pressure is within 0.1Mpa. Their distinctive feature is a thick edge at the end. Tees are used for vertical cross connections; reducing tees are used to connect two smaller diameter branches to a pipe vertically; reducers, also known as male and female threads, have a smaller male thread and a larger female thread, with the female thread connecting to other fittings and the male thread directly connecting to the pipe, used for pipe diameter changes; external screw short joints are used to connect two adjacent pipe fittings; commonly replaced with short pipe joints turned on a lathe, very short joints are called couplings; plug, also known as a plug or cap, has an external thread to seal the opening of the fitting; swivel joints consist of two male and female pipe ends that can interlock and a sleeve to connect them, with a gasket or asbestos paper to prevent leakage; swivel joints are used where flexible connections are needed in pipe systems, allowing pipes to be disconnected without turning them; they are essential for dismantling and repairing equipment in pipe systems; root nuts, also known as root bands or lock nuts, are a short pipe with one end having a short threaded end and the other a long threaded end (root without taper).