Annular seat for butterfly and ball valves - has stainless steel envelope and asbestos filling to resist high temperatures and pressures

摘要

The annular valve seat (1) is for use in butterfly and ball type valves to resist high temperatures and pressures. The seat is installed in a recess in the valve body, being retained by a screw ring or similar. It has an outer envelope (7) of stainless steel, formed to give a trapezoidal cross section having the inner surface (11) comprising the bore, at an angle (11A) of approx. 15 deg. A small bevelled edge (12A) is at the opposite corner. The seating surface (15) has one or two steps to increase sealing efficiency and the interior of the seat is filled with an asbestos fibre mix (16).