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Four-way Valve
The four-way valve or four-way cock is a fluid control valve whose body has four ports. One commonly used form—the rotary four way valve—has equally spaced ports around the valve chamber and a plug with two passages that connect pairs of adjacent ports. The plug may be cylindrical, tapered, or a ball. It has two flow positions, and usually a central position where all ports are closed. An application of this design is to isolate and to simultaneously bypass a sampling cylinder installed on a pressurized water line. It is useful to take a fluid sample without affecting the pressure of a hydraulic system and to avoid degassing (no leak, no gas loss or air entry, no external contamination). Another common use case is to reverse the flow of fluid through some portion of a system. An example is a reversible heat pump, where a four-way valve reconnects the two heat exchangers to be either evaporator or condenser. It was used to control the flow of steam in the valve gear of earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-Way Cock
4-way or Fourway can refer to: *an acoustic system containing four loudspeakers *a formation skydiving event, "4-way sequential", that has four members in each team *a Symmetric multiprocessing Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all ... system with 4 processors * Fourway Athletics, a Hong Kong football team * Four-slide * Four-way switch * 4-way stop * Fourway, Virginia (other) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valve
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or Slurry, slurries) by opening, closing, or partially obstructing various passageways. Valves are technically Piping and plumbing fitting, 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 word is derived from the Latin ''valva'', the moving part of a door, in turn from ''volvere'', to turn, roll. The simplest, and very ancient, valve is simply a freely hinged flap which swings down to obstruct fluid (gas or liquid) flow in one direction, but is pushed up by the flow itself when the flow is moving in the opposite direction. This is called a check valve, as it prevents or "checks" the flow in one direction. Modern control valves may regulate pressure or Fluid dynamics, flow downstream and operate on sophisticated Automation#Industrial automation, automat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valve Gear
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle. It can also serve as a reversing gear. It is sometimes referred to as the "motion". Purpose In the simple case, this can be a relatively simple task as in the internal combustion engine in which the valves always open and close at the same points. This is not the ideal arrangement for a steam engine, though, because greatest power is achieved by keeping the inlet valve open throughout the power stroke (thus having full boiler pressure, minus transmission losses, against the piston throughout the stroke) while peak efficiency is achieved by only having the inlet valve open for a short time and then letting the steam expand in the cylinder (expansive working). The point at which steam stops being admitted to the cylinder is known as the '' cutoff'', and the optimal posit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Trevithick
Richard Trevithick (13 April 1771 – 22 April 1833) was a British inventor and mining engineer. The son of a mining captain, and born in the mining heartland of Cornwall, Trevithick was immersed in mining and engineering from an early age. He was an early pioneer of steam-powered road and rail transport, and his most significant contributions were the development of the first high-pressure steam engine and the first working railway steam locomotive. The world's first locomotive-hauled railway journey took place on 21 February 1804, when Trevithick's unnamed steam locomotive hauled a train along the tramway of the Penydarren Ironworks, in Merthyr Tydfil, Wales. Turning his interests abroad Trevithick also worked as a mining consultant in Peru and later explored parts of Costa Rica. Throughout his professional career he went through many ups and downs and at one point faced financial ruin, also suffering from the strong rivalry of many mining and steam engineers of the day. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denis Papin
Denis Papin FRS (; 22 August 1647 – 26 August 1713) was a French physicist, mathematician and inventor, best known for his pioneering invention of the steam digester, the forerunner of the pressure cooker, the steam engine, the centrifugal pump, submersible and possibly the paddlesteamer (1707). Early life and education Born in Chitenay (Loir-et-Cher, Centre-Val de Loire Région), Papin attended a Jesuit school there. In 1661, he attended the University of Angers, from which he graduated with a medical degree in 1669. Career In 1673, Papin worked with Christiaan Huygens and Gottfried Leibniz in Paris, and became interested in using a vacuum to generate motive power. In 1675, he first visited London, where he worked with Robert Boyle from 1676 to 1679, publishing an account of his work in ''Continuation of New Experiments'' (1680). During this period, Papin invented the '' steam digester,'' a type of pressure cooker with a safety valve. He first addressed the Roya ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball Valve
A ball valve is a flow control device which uses a hollow, perforated, and pivoting ball to control fluid flowing through it. It is open when the hole through the middle of the ball is in line with the flow inlet and closed when it is pivoted 90 degrees by the valve handle, blocking the flow. The handle lies flat in alignment with the flow when open, and is perpendicular to it when closed, making for easy visual confirmation of the valve's status. The shut position 1/4 turn could be in either clockwise or counter-clockwise direction. Ball valves are durable, performing well after many cycles, and reliable, closing securely even after long periods of disuse. These qualities make them an excellent choice for shutoff and control applications, where they are often preferred to gates and globe valves, but they lack the fine control of those alternatives, in throttling applications. The ball valve's ease of operation, repair, and versatility lend it to extensive industrial use, sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
