Abstract: A sealing structure for use in valves, including butterfly valves, having a body with a flow passage and a movable valve disc in the flow passage. Two sealing surfaces are mounted in the body to engage the disc when it is in a closed position to provide a bubble-tight seal. The sealing structure includes an annular seal retaining cavity with a slot opening to the flow passage. A metal seal ring having a lip portion (which has a first seat) projecting through the slot into the passage is contained within the cavity adjacent to a primary heat-destructible seal ring, which has a second seat. The first seat and the second seat are engageable with the sealing surface of the disc to provide two axial seals. When the valve is closed, a radially-directed force is developed at the second seat (on the heat-destructible seal) and at the first seat (on the lip portion of the metal seal) in response to contact with the disc to effect a heat-destructible seal and a second, metal-to-metal seal, respectively.