Atmospheric aging resistance: radiation resistance and low permeability: long-term exposure to the atmosphere, the surface and performance remain unchanged. Non-combustibility: The oxygen limit index is below 90. Acid and alkali resistance: insoluble in strong acids, strong alkalis and organic solvents. Oxidation resistance: resistant to corrosion by strong oxidants. Working characteristics of steel-lined PTFE pipeline: Performance: Medium working temperature: -100℃~-250℃. Medium working pressure: positive pressure: 2.5MPa, negative pressure resistance 70KPa at room temperature.