Assertion: snorkel's valve | /r/CapableOf | close the outlet orifice
Facets:
value: to prevent water
type: PURPOSE
Source sentences:
text: The exhalation tube 52 terminates in an air outlet orifice 58 which incorporates a gravity operated valve 60 which closes the outlet orifice 58 to prevent water from splashing into the exhalation tube, but which opens when air is exhausted or when the snorkel is completely submerged.