Static pressure automatic control device for closed circuit respirator

摘要

A static pressure automatic control device for respirators of closed-circuit type comprises an exhaled air passage which is branched out of an exhalation system of a respirator and a static pressure discharge valve connected in series to this exhaled air passage. A respiratory dynamic pressure generated by exhalation is attenuated due to resistance encountered while the exhaled air is being passed through the exhaled air passage and substantially the static pressure only is applied to the discharge valve. When the static pressure exceeds a predetermined value, the discharge valve opens to let out a part of gas and thereby decreases the static pressure to the predetermined value.