valve

A device that controls the flow of a gas or fluid through a space, such as a pipe, manifold, or plenum.

open the valve

close the valve

A device that controls the flow of a gas or fluid through a space, such as a pipe, manifold, or plenum.

Near-synonym: poppet valve

In nearly all internal combustion engines, the valves are of the poppet type.

One or more membranous partitions, flaps, or folds, which permit the passage of the contents of a vessel or cavity in one direction, but stop or control the flow in the opposite direction.

the ileocecal valve

the atrioventricular valves

One of the leaves of a folding door or of a window sash.

A vacuum tube.

To control (flow) by means of a valve.