Visual inspection of the speech diaphragm:
The speech diaphragm and O-ring must be clean and undamaged. If not, clean or replace.
Visual inspection of inhalation valve:
The inhalation valve is visible in the mask connector. Check by blowing into it that both wings of the valve disc move freely. Replace if seized.
Visual inspection of exhalation valve:
Remove the protective cap from the connector. Press one arm of the spring clamp inwards and remove the clamp. Hold valve disc by the nipple and lift out of guide. The valve disc and seat must be clean and undamaged. Clean or replace if necessary. Moisten valve disc with water and refit. When the seat is horizontal, the valve disc must slide into the guide under its own weight. Fit spring clamp and spring so that both clamp arms engage at the sides. The clamp is marked “L”= left and “R” right and fits at an angle.
