Butterfly valve

In a valve having a valve body defining an axial flow passageway, a valving member retained within said valve body and pivoted about an axis transverse to said passageway between an open and closed position for interrupting fluid flow through said valve, an annular groove in the valve body communicating with the passageway, and a fire-safe sealing means for providing a fluid seal between said valving member and said passageway interior surface, the improvement comprising, in said fire-safe sealing means, the combination of:

• a seating groove extending axially of said annular groove;
• a seal ring, disposed in said annular groove and having an axial annular projection for seating said sealing ring in said seating groove and having a sealing surface projecting radially inwardly therefrom into said passageway, said sealing surface being engageable by the peripheral sealing surface of said valving member, said sealing surface having an inverted resilient J-shaped portion in cross-section, said seal ring having a slot for receiving a metal ring for retaining said seal ring in the circumferential direction;
• a retaining ring for retaining said seal ring in said annular and seating grooves, said ring having a blocking groove extending axially and inwardly thereof for receiving the distal end of said resilient J-shaped portion;
• and
• an annular fire-resistant seat disposed between said seal ring and said retaining ring, said annular fire-resistant seat extending radially inwardly around said seal ring and J-shaped portion to abut the peripheral sealing surface of said valving member when said valving member is in a closed position.