The air seal in a metal outer burial container works by trapping air inside the dome when it is placed over the base. That trapped air exerts outward pressure against groundwater, creating a passive seal that resists moisture infiltration without relying on adhesives or gaskets. The principle is mechanical and does not degrade over time the way chemical sealants do.
CMV Fabrication integrates air-seal construction into its metal OBC product line and water-tests every finished unit before it ships. This testing confirms that each individual outer burial container creates and holds the air seal under simulated ground conditions. The combination of air-seal geometry, continuously welded seams, and powder coat finishing produces an outer burial container with multiple independent moisture barriers.
