Doors and other closures can be positively sealed by using Pneuma-Seal inflatable seals. The seal is inflated with air or other fluid by a pressure-regulated supply system (which can also be furnished by them). When pressurized, the inflatable seal conforms to uneven surfaces and provides an efficient, reliable barrier to dust, moisture, contaminants, and/or pressure differential.

Operating pressures are usually in the range of 10 to 35 PSI but some of the inflatable seals can be designed to operate at lower pressures, in the order of 5 PSI or less, or at higher pressures of 100 PSI or more. Expansion capabilities, the ability to close a "gap", vary from cross section to cross section. Large "gaps" may be accommodated but it should be noted that as the gap increases, the pressure required to seal against a given pressure differential increases, thereby decreasing the inflatable seal's flex life.