Valve definition

What is the definition of heart valve? Any of various devices that regulate the flow of gases, liquids, or loose materials through. English dictionary definition of valve. Valves are technically fittings, but are usually discussed as a separate category.

In an open valve , fluid flows in a direction from higher pressure to lower pressure.

The definition of a valve is a device that opens or closes to let things through or to prevent passage. The part of your heart that opens and closes to let blood enter or to prevent blood from entering is an example of a valve. In a scientific context, fluids include both liquids and gases – any substance that can flow freely – and valves may use either. A valve is a mechanism that opens and closes to control the flow of fluids. Valves control fluid flow in motors, plumbing, irrigation, pneumatic and hydraulic systems.

For a young person with a tissue valve replacement, the need for additional surgery or another valve replacement later in life is highly likely. A check valve , clack valve , non-return valve , reflux valve , retention valve or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves , meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave.

Gate valve definition is - a valve in a pipeline consisting essentially of a flat or wedge-shaped gate that can be lowered into a seat to seal off the line or raised into an external recess so that the full area of the line is open. It is composed of three semilunar cusps and prevents regurgitation of blood from the pulmonary artery into the right ventricle. See: cardiac valve for illus. 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.

Valves to move forward h, Central muscles (close valves). The valves are distinguished as dorsal and ventral. The two valves of the shell of the common cockle are similar to each other, and somewhat circular in outline. The main types of values include: (1). A spool valve is part of a hydraulic system that directs the flow of hydraulic fluid.

In valve stenosis, the valve flaps become thick or stiff, and they may fuse together. This in a narrowed valve opening and reduced blood flow through the valve. Aortic valve disease may be a condition present at birth (congenital heart disease), or it may result from other causes. The purpose of these is to hold the packing material of the valve tightly in place so there are no leaks. Sometimes the packing nuts can be too tight or too loose.

If the valve handle on an OSY valve will not move, the packing may be too tight. In internal combustion engines, pumps, compressors, and blowers, a valve is a part of the distribution mechanism or of the gas or fluid flow-control mechanism.

A device that admits fuel and air into the cylinder of an internal combustion engine, or one that allows combustion gases to exit. Oxford Dictionaries as A device for controlling the passage of fluid or air through a pipe, duct, etc. AIR SET: Also SUPPLY PRESSURE REGULATOR. A device used to reduce plant air supply to valve POSITIONERS and other control equipment.

Common reduced air supply pressures are and psig. Definition - What does Gate Valve mean? A gate valve has a flat closure element that slides into the flow stream to stop the fluid.

They are one of the most commonly used valves, and are primarily used to permit or prevent the flow of liquids. The handle and the stem are both threaded so they interact together. The stem of the valve itself raises and lowers visibly outside the body of the valve , while the handle remains in a fixed position.