JB/ T10706-2007 "Mechanical seal with fluorine plastic fully covered rubber O-ring" is suitable for fluorine, silicone rubber inner core fully covered FEP/PFA fluorine plastic, and special process composite of special rubber O-ring, can be applied in the ordinary rubber O-ring can not adapt to some chemical media environment, elasticity provided by the rubber inner core. Chemical media resistance is provided by seamless FEP/PFA bushing.