View all text of Subpart L [§ 84.190 - § 84.207]
§ 84.204 - Exhalation valve leakage test; minimum requirements.
(a) Dry exhalation valves and valve seats will be subjected to a suction of 25 mm. water-column height while in a normal operating position.
(b) Leakage between the valve and valve seat shall not exceed 30 milliliters per minute.