Fluorine-lined valves use fluoroplastics such as polytetrafluoroethylene, and the valve body is isolated from corrosive media through molding or inlaying processes. There are also differences in the materials selected for different media. If it is an organic solvent containing benzene, PVDF lining is prohibited. If it is fuming sulfuric acid, PCTFE material is recommended.
In addition, there are related red lines for the installation of fluorine-lined valves!
1. Flame baking of flange sealing surfaces is prohibited (＞150℃ will cause carbonization of fluoroplastics)
2. Bolt tightening should be done with diagonal progressive pressure (error ≤5N·m)
When a fluorine-lined valve suddenly leaks, liquid nitrogen should be injected in time for local cooling, and the shrinkage characteristics of fluoroplastics should be used to achieve temporary sealing.