Coke oven door with wraparound gas channel and membrane

A coke-oven door has an annular periphery normally juxtaposed with an annular door frame. A seal assembly for the door has at least two flexible, relatively displaceable, metallic, and annular membranes each having an annular inner periphery and an annular outer periphery and a U-section channel fixed to the outer periphery of only one of the membranes, open toward the door, and having annular inner and outer edges. The other membrane bears on the one membrane and therethrough on the channel. A mount secures the inner peripheries of the membranes to the periphery of the door. A spring urges the edges of the channel with a spring force against the door frame.