safety valve

noun

1. a device that, when actuated by a gas or vapor pressure above a predetermined level, opens and allows the gas or vapor to escape until its pressure is reduced to a pressure equal to or below that of the predetermined level. Compare relief valve.
2. a harmless outlet for emotion, tension, etc.

safety valve

noun

1. a valve in a pressure vessel that allows fluid to escape when a predetermined level of pressure has been reached
2. a harmless outlet for emotion, energy, tension, etc

Word History and Origins

Origin of safety valve¹

First recorded in 1805–15

Example Sentences

Any CO2 pipelines in Kern County will be equipped with automatic safety valves, which are expected to limit leakage in the event of a rupture.

From Los Angeles Times

Last November, Sable sued Santa Barbara County for denying its permits to install automatic safety valves, a critical requirement for operations to begin.

From Los Angeles Times

“Netanyahu knows better than I do,” she said, “the best thing is to let it play as a safety valve – let people say, ‘we hate you, you are a murderer’.”

From BBC

They asked councils in the safety valve programme to provide details of what they would involve, receiving some information from 27.

From BBC

Under a provision known as the “safety valve,” judges can disregard federal mandatory minimum sentences for people with limited criminal history convicted of certain nonviolent drug offenses.

From New York Times