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هایدی SELECTION AND APPLICATION OF VALVES Mohinder L. Nayyar, P.E. ASME Fellow دانلود با لینک مستقیم و پر سرعت .
Valves are an essential part of any piping system that conveys liquids, gases, vapors,
slurries and mixtures of liquid, and gaseous phases of various flow media. Starting
with primitive means for stopping, allowing, or diverting water-flow from a source
through shallow or deep channels, such as wooden or stone wedges stuck between
the edges of a water passage, man has developed several different types of simple
and sophisticated valve designs. Different types of valves include: gate, globe, check,
ball, plug, butterfly, diaphragm, pinch, pressure relief, and control valves. Each of
these types has several categories and designs, each offering different features and
functional capabilities. Some valves are self-actuated while others are manually
operated or have actuators that are powered with electric motors, are pneumatic
or hydraulic, or a combination to operate the valve. Valves are manufactured with
metals and nonmetals. Valves are used in industrial piping systems, transportation
and distribution pipelines, building services piping, civic facilities, and irrigation
piping systems. The piping systems of industrial, commercial, residential, and other
civic facilities carry the lifeblood of modern civilization, like arteries and veins.
And the valves in those piping systems serve the functions of allowing, stopping,
regulating, and controlling the flow, to fulfill the intended objectives of the system.
When fluid pressure builds up beyond a set limit, the valves relieve the overpressure
to safeguard the integrity of the piping system or a component. Valves help in
maintaining or breaking a vacuum. Valves also assist in maintaining the pressure
or temperature of the flow medium within the desired range or limit. In order to
select a suitable valve for a particular application, the user must evaluate the
valve characteristics, including the design features, materials of construction, and
performance, in light of specific application requirements: flow medium, process
design requirements, piping design criteria, and economic factors. This chapter
provides a brief discussion of topics considered in the selection and application of
commonly used valves.
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SELECTION AND APPLICATION OF VALVES Mohinder L. Nayyar, P.E. ASME Fellow 
