Boiler penthouse access door

摘要

A door system for a boiler penthouse or other high temperature industrial environment is disclosed. A sufficiently large entranceway for both workmen and large equipment is provided by the door system. The access door has the capability for quick gas-tight sealing during closing. A hinged metal door plate has arcuate welding beads applied to its internal surface near its corners to produce permanent inward cupping of the door plate adjacent to its corners. Devices apply pressure to the exterior surface of the door plate during the closing thereof to flatten the inwardly cupped corners and effect gas-tight sealing of the interior surface of the door plate near its margin with an opposing high temperature resistant gasket carried by the front face of a refractory insulated door frame. A layer of thermal insulating material in a protective jacket is secured to the interior surface of the door plate.