Four-fluorine-lined pipes are a type of steel cluster composite pipeline that can withstand strong acids and alkalis. Over the years of actual use, the direct factors affecting the service life and performance stability of PTFE-lined anti-corrosion pipes are temperature, pressure, medium, and so on. Good materials and advanced manufacturing processes ensure the quality of PTFE-lined products. Steel-lined PTFE straight pipes are commonly known as loose-lining pipes. Their characteristics are as follows: 1. High operating temperature: Under conditions of strong corrosive media, it can meet the operating temperature range of -60 to 200 degrees Celsius, within which it can satisfy all chemical media. 2. Vacuum resistance: Can be used under vacuum conditions, often causing partial vacuum states in chemical production due to cooling, longitudinal discharge, and unsynchronized operation of pumps and valves. 3. High-pressure resistance: Within the operating temperature range, it can withstand a pressure of up to 3MPa. 4. Permeation resistance: Uses PTFE resin, processed into a high-density, thick PTFE lining layer through advanced lining technology, ensuring good permeation resistance. 5. Integrated molding sintering process of the lining solves the problem of cold and hot expansion of steel and fluorine, achieving synchronous expansion. 6. Standardized size configuration is adopted, especially for pipes and pipe fittings used in chemical pipelines, which have strong interchangeability, greatly facilitating installation and spare parts.