Abstract: A sealing beam comprises a longitudinal succession of elements disposed between two grate layers made up of a longitudinal succession of alternately fixed and mobile (in longitudinal reciprocation) bars. Each element comprises an I-shaped armature with a web between a lower flange forming a baseplate and an upper flange forming a roof and two U-shaped profile rubbing members with a base bearing on the edge of the corresponding grate layer. Springs passing through holes in the web of the armature urge the rubbing members against the layer edges to compensate for their thermal expansion. The armature and the rubbing members are manufactured by welding to achieve adequate sealing between the rubbing members and the armature.