valve

/vælv/

/vælv/

Other forms: valves

A valve is a device that controls the flow of a liquid or gas. Before you fix the broken sink in your bathroom, you should turn the valve that shuts off the water.

The simplest type of valve has a hinged flap allowing liquid to flow one direction, but blocking it from going the other way. This is called a "check valve." Anatomical valves — systems in your body that allow a flow of fluid, like the aortic valve near your heart — are structured very much the same way. The shells of mollusks like oysters and clams are also called valves. The word's earliest meaning was "one half of a folding door."

Definitions of valve

1. noun

   control consisting of a mechanical device for controlling the flow of a fluid
   types:

   accelerator, throttle, throttle valve

   a valve that regulates the supply of fuel to the engine

   ball valve

   any valve that checks flow by the seating of a ball

   butterfly valve

   a valve in a carburetor that consists of a disc that turns and acts as a throttle

   choke

   a valve that controls the flow of air into the carburetor of a gasoline engine

   clack, clack valve, clapper valve

   a simple valve with a hinge on one side; allows fluid to flow in only one direction

   exhaust valve

   a valve through which burned gases from a cylinder escape into the exhaust manifold

   intake valve

   a valve that controls the flow of fluid through an intake

   poppet, poppet valve

   a mushroom-shaped valve that rises perpendicularly from its seat; commonly used in internal-combustion engines

   escape, escape cock, escape valve, relief valve, safety valve

   a valve in a container in which pressure can build up (as a steam boiler); it opens automatically when the pressure reaches a dangerous level

   slide valve

   valve that opens and closes a passageway by sliding over a port

   automatic choke

   a choke that automatically controls the flow of air to the carburetor

   type of:

   control, controller

   a mechanism that controls the operation of a machine
2. noun

   a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it
   types:

   cardiac valve, heart valve

   a valve to control one-way flow of blood

   valvelet, valvula, valvule

   a small valve

   ileocecal valve

   valve between the ileum of the small intestine and the cecum of the large intestine; prevents material from flowing back from the large to the small intestine

   atrioventricular valve

   either of two heart valves through which blood flows from the atria to the ventricles; prevents return of blood to the atrium

   semilunar valve

   a heart valve with cusps shaped like half-moons; prevents blood from flowing back into the heart

   type of:

   anatomical structure, bodily structure, body structure, complex body part, structure

   a particular complex anatomical part of a living thing
3. noun

   device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
   type of:

   device

   an instrumentality invented for a particular purpose
4. noun

   the entire one-piece shell of a snail and certain other molluscs
   type of:

   shell

   the hard largely calcareous covering of a mollusk or a brachiopod
5. noun

   one of the paired hinged shells of certain molluscs and of brachiopods
   type of:

   shell

   the hard largely calcareous covering of a mollusk or a brachiopod