A closure seal for
doors, hatches and the like comprising a pneumatically
inflatable sealing element of generally known configuration housed in a specially constructed channel-shaped
retainer. The sealing element comprises a flat, relatively stiff base portion of predetermined width and a flexible portion comprising spaced apart side walls, joined with the base, and an outer wall joining with the side walls to form a hollow expandable section. The base forms shoulders where it joins with the side walls. A retaining channel, formed of sheet
metal and of generally U-shaped cross section, receives the sealing element and is formed with longitudinally spaced apart, opposed, inwardly projecting elements forming longitudinally spaced apart constrictions of slightly less width than the base of the sealing element. The sealing element is inserted in the retaining channel, with the base of the element being forced through the constrictions, and thereafter is retained in the channel by engagement of the shoulders of the base by the spaced apart projection pairs.