Inhalation 24 : valve A device that allows air to enter the facepiece of a breathing apparatus and prevents exhaled air from leaving the facepiece through the intake opening. See also: Exhalation Valve
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}