Abstract: A coke-oven door seal and sealing system wherein the coke-oven door seal comprises a sealing arm in angular relation with a door jamb surface, said sealing arm being engagable with said door jamb surface at a knife edge, and said sealing arm protruding beyond said knife edge and away from said door jamb surface creating a reinforcing and ventilating rib for cooling said knife edge which is capable of supporting a secondary sealing means. The sealing system of the present invention comprises a coke-oven door seal, including a sealing arm in angular relation with a door jamb surface, said sealing arm protruding beyond the knife edge at which said sealing arm engages said door jamb surface and a pivotable plunger system which comprises a standard plunger connected to a plunger extension which consists of a pad and a ball joint or other swivel or rocking means.