Air Valve

Then, with the bright copper dome of the helmet showing as a little disc upon the water, he paused and adjusted the air-valve, that bubbled with a little splutter of white foam. ❋ Unknown (2010)

The diver sat for a minute adjusting the air-valve by his ear; then he got up with an effort and walked two steps to the bulwarks. ❋ Unknown (2010)

Unless the rising main is a long one, it will seldom be necessary to incorporate an air-valve and only in exceptional conditions should this be done for a short rising main. ❋ Unknown (1999)

You may set the air-valve fast or slow, and the torpedo will go accordingly. ❋ William Charles Henry Wood (1905)

This done the professor opened the main air-valve, gradually admitting a certain quantity of air into the ship's interior, and she at once began to drop once more earthward. ❋ Harry Collingwood (1886)

The professor opened the air-valve and the ship at once began to settle down. ❋ Harry Collingwood (1886)

Therewith he laid his hand upon a small wheel, and gave it two or three turns, thus partially opening the main air-valve and admitting a thin stream of air into the vacuum chambers of the _Flying Fish_, with the result that the huge craft at once began to settle down toward the surface of the sea, upon which, a few minutes later, she floated buoyantly as a soap-bubble. ❋ Harry Collingwood (1886)

He stopped the engines, opened the air-valve, and the great ship instantly began to settle quietly down. ❋ Harry Collingwood (1886)

After all, if she acts up, you can just pull open her air-valve. ❋ Unknown (2011)

The air-valve piston within the air-valve body routes the air supply to one of two air chambers. ❋ Unknown (2010)