Abstract: An apparatus and system stores and supplies liquid CO.sub.2 at low pressure for extinguishing fires. The apparatus comprises a pressure vessel (13) for storing liquid CO.sub.2 at low pressure, a cooling device (29) in contact with gaseous CO.sub.2 in the vessel to maintain the low pressure, an inlet (24) and outlet (32) to fill the vessel and a supply conduit (17) communicating with a lower portion of the interior of the vessel to allow liquid CO.sub.2 to pass from the vessel and into a reticulation system. A number of pressure vessels can be coupled together through a manifold (165) to provide the required amount of liquid CO.sub.2 to a risk site. Supply valves (18) or manifold valves (173, 174) can be operated by a sensor (175, 176) in a risk site and a logic processor (177) can be used to regulate the valves and thereby the liquid CO.sub.2. The apparatus and system is particularly designed as a replacement for current halon systems which cause damage to the ozone layer.

Abstract: A self-energizing seal system employing plastically deformable nonelastomeric elements to establish sealing integrity between concentric, relatively movable tubular conduits is disclosed. The primary sealing element comprises a chevron-shaped thermoplastic virgin polytetrafluoroethylene member. A plurality of back-to-back primary sealing elements are employed, thus creating a relatively frictionless interface along which radial expansion of the chevron-shaped members can occur. Annular back up members of polyphenylene sulfide and glass-filled polytetrafluoroethylene are used to inhibit axial extrusion of the chevron-shaped sealing members during radial expansion thus promoting sealing integrity.