摘要 |
Breathing equipment for use in toxic atmospheres or beneath water including a breathing mask, a pressure regulator adjacent the source of breathing gas, and a source of breathing gas. A conduit transports breathing gas from the source of breathing gas to the mask. The conduit includes an inner conduit that functions to transport breathing gas to the breathing mask from the pressure regulator, and an outer conduit that surrounds the inner conduit and that protects the inner conduit and defines therewith a passageway that is sealed against the surroundings. The inner conduit is connected to the breathing mask so as to deliver thereto breathing gas that leaks from the inner conduit and does not normally transport breathing gas therethrough. A pressure regulating valve connects the inner conduit to the breathing mask and delivers breathing gas to the breathing mask at an overpressure. |