Plastic-lined pipes are a specialized pipeline material with excellent temperature resistance and corrosion resistance, making them ideal for transporting strong corrosive media such as nitric acid, aqua regia, mixed acids, bromides, and other organic solvents. Plastic-lined straight pipes: these are steel pipes lined with plastic, divided into molded steel-lined plastic pipes and steel tube-lined plastic pipes. Molded pipes: primarily formed through molding, using molds and hydraulic pressure, then baked in an oven. Such pipes are commonly used in high vacuum and harsh medium environments, showing significant effects, though they are relatively costly. Tube-lined plastic pipes: these are tubes pushed directly onto steel pipes (produced by tube forming machines, with uniform wall thickness and good density), and then the ends are processed for flanging. These pipes are relatively cheaper and suitable for less harsh medium environments.