ABSTRACT
All machines have an emergency O2 flush valve which, when activated, supplies O2 at a minimum rate of 30 L/min. It is connected directly to the common gas outlet from the pipeline and the first-stage cylinder regulator, as shown in Figure 8.29. Older machines have a locking system to allow it to be kept on but, because of inadvertent barotrauma being caused by this, current recommendations are that it should not be capable of being locked on. The knob is also recessed to reduce the chances of accidental activation.
