... chemical medium. -Good corrosion resistance and compression -W PTFE O ring:Feature:1. Outstanding chemical resistance ,apply ... valve, sealing parts, filter, reaction vessel, pressure vessel, heat exchanger, boiler, ther flange of pipe line.Applicabe industtry: ... film, industry film, refrigeration engineering, food processing, paper-making industry, paints,varnishes,lacquers,pigments manufacturing.