Valve is a device that is used to regulate, direct or control the flow
of some liquid, such as gases, liquids, fluidized solids, slurries, etc. These
functions are carried out by opening, closing, or partially obstructing the various
passageways. In most of the arenas, the valves serve as valves fittings, but they
still fall in a different category. These are fabricated in a number of
specifications to suit the particular industrial application.