| 摘要 |
A breathing apparatus includes two parallel flowpaths 4 and 12 through which breathing gas can be supplied independently from a cylinder 1 to a facemask 6. The first flowpath 4 includes a shut-off valve 2, pressure reducer 3 and demand valve 5 and provides the normal route through which the user of the apparatus is supplied. In the event of a failure or malfunction of any component of this normal breathing circuit, however, the first flowpath can be isolated by closing the valve 2 and the user can breathe through the second or bypass flowpath by opening a second shut-off valve 11 which has a combined pressure reducer and leads directly to the mask 6. The two valves 2 and 11, together with a cylinder pressure gauge 14 and a safety burst disc 15, are incorporated in a compact valve assembly 13 secured to the cylinder 1. |
