ball valve

noun Machinery.

1. a valve controlling flow by means of a ball pierced with an opening in one direction and fixed to rotate on a spindle at right angles to the opening.
2. any valve that checks flow by the seating of a ball.

noun

1. a one-way valve consisting of a metal ball with a cylindrical hole fitting into a concave seat over an opening

n.

1. A valve regulated by the position of a free-floating ball that moves in response to fluid or mechanical pressure.