... and maintain.2, The double eccentric structure friction of the sealing ring, providing the valve a long service ... .4, Replacing materials of the disc sealing ring and disc, the valve can be used for ... plug valves strainers, etc.in accordance with the latest international standards of ANSI,DIN, JIS, ... USA,South America, Europe,and the Middle East Area.we always supply the high-quality products and best ...