Weinmann JOYCE SilkGel vented Instructions For Use Manual page 29

Product description
3.4 Emergency exhalation valve
The vented full-face masks also have an emergency exhalation valve
10 (Figure C). The emergency exhalation valve has an opening to
the atmosphere through which you can inhale ambient air if the
therapy device fails. As long as the therapy device is in operation,
the membrane is forced against the opening by the air flow and
seals it. If the therapy device fails, the opening is free so that
ambient air flows into the mask.
3.5 Pressure measurement connections
The mask has two connections 6 which you can use for measuring
pressure or for supplying oxygen. If you are not using the
connections, seal them using plug 5 in order to achieve therapy
pressure (Figure D).
3.6 Quick-release feature (optional)
A quick-release feature is available as an option for full-face masks.
The quick-release feature is for opening the headgear clips quickly
in emergency situations. The quick-release feature consists of a
special clip with a rip-cord which is fitted instead of one of the
bottom headgear clips. When you pull on the rip-cord, the special
clip opens immediately and you can remove the mask.
JOYCE SilkGel EN 27