vent

Some scholars hypothesize that the fire-spitting natural gas vents in southern Turkey may have sparked stories of this flame-blowing beast.

If you look very carefully, you'll notice the vents are actually slightly bigger and the interior is redesigned to allow for more airflow.

Different compounds than we have on Earth could be coming out of volcanoes and vents and this could confuse us as to what we think we're finding.

But when a big enough bubble grows in the pipe, the float acts like a weight and pulls the valve open, venting the air from the pipe.