Non-lubricated are used in process where minimum maintenance is required. They are usually not lubricated and it is limited by temperature and chemical compatibility. A plug valve is uniquely quarter-turn manual valve with cylindrical or tapered plug which or prevent direct flow through the body. Plug valve can be operated in on-off, and basic moderate throttling, and diverting services. Plug Valve design is face-to-face with ANSI Standard B16.10. Plug valves can be sub or as replacement for gate valve in many operations and application. Applications: Low pressure temperature and some high temperature services. To regulate flow of liquid or slurry that contains suspended solids.