escape valve

Is it the Internet as an escape valve for decades of pent-up rebellion against political correctness?

We have kept them pent up all the evening, and that is the escape-valve being raised to avoid a general explosion.

They were discussing the escape-valve in a diver's helmet, and arguing whether it pays to stiffen the spring for very deep diving.

The pressure escape valve is often attached to this hydraulic valve body.

She knew that she was simply serving as an escape-valve, and that after the steam was "let off" she would be more rational.

An escape valve had been set to maintain one atmosphere of pressure about them.