Commercial Entry Exit Door Weather Strip Pile Seals Astragal Seals: An astragal seal or meeting stile seal is commonly used to seal between a pair of doors, inswing or outswing, and the vertical pile track member or molding attaches to a stile on one of a pair of either sliding or swinging doors, against which the other door seals when closed. Exterior astragals are "kerfed" for weather stripping.