Valve Made by Hilevskiy V. MA-82
General information • A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically pipe 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 simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction.
Scheme Cross-sectional diagram of an open globe valve. 1. body 2. ports 3. seat 4. stem 5. disc when valve is open 6. handle or handwheel when valve is open 7. bonnet 8. packing 9. gland nut 10. fluid flow when valve is open 11. position of disc if valve were shut 12. position of handle or handwheel if valve were shut
Using • Valves are used in a variety of contexts, including industrial, military, commercial, residential, and transport. The industries in which the majority of valves are used are oil and gas, power generation, mining, water reticulation, sewage and chemical manufacturing. • In daily life, most noticeable are plumbing valves, such as taps for tap water. Other familiar examples include gas control valves on cookers, small valves fitted to washing machines and dishwashers, safety devices fitted to hot water systems, and valves in car engines. In nature, veins acting as valves are controlling the blood circulation; heart valves control the flow of blood in the chambers of the heart and maintain the correct pumping action.
Applications • Valves vary widely in form and application. Sizes typically range from 0. 1 mm to 60 cm. Special valves can have a diameter exceeding 5 meters. • Valve cost ranges from simple inexpensive disposable valves to specialized valves cost thousands of US dollars per inch of diameter. • Disposable valves may be found inside common household items including mini-pump dispensers and aerosol cans.
Types • Valves are quite diverse and may be classified into a number of basic types. Valves may also be classified by how they are actuated: • • Hydraulic Pneumatic Manual Solenoid
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