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A piston valve is a device used to control the motion of a fluid or gas along a tube or pipe by means of the linear motion of a piston within a chamber or cylinder. [1]
Examples of piston valves are:
[2] Cylindrical piston valves called Périnet valves [3] (after their inventor François Périnet) are used to change the length of tube in the playing of most brass instruments, particularly the trumpet-like members of the family (cornet, flugelhorn, saxhorn, etc.).
Other brass instruments use rotary valves, notably the orchestral horns and many tuba models, but also a number of rotary-valved variants of those brass instruments which more commonly employ piston valves.
The first piston-valved musical instruments were developed just after the start of the 19th century. The Stölzel valve (invented by Heinrich Stölzel in 1814) was an early variety. In the mid 19th century the Vienna valve was an improved design. However most professional musicians preferred rotary valves for quicker, more reliable action, until better designs of piston valves were mass manufactured towards the end of the 19th century.
A piston valve can also refer to a 2-way 2-position, pilot-operated spool valve. [4] The term is extremely popular among spud gun enthusiasts who often build homemade piston valves for use in pneumatic cannon. Valves are typically constructed primarily from pipe fittings and machined plastics or metals. The inside of a piston valve contains a piston that blocks the output when the valve is pressurized, and a volume of air behind the piston. When the pressure behind the piston is released the piston is pushed back by the force of the pressure from the input. This allows the valve to be opened by a much smaller pilot valve, with speeds faster than possible with just a manually operated valve. Functionally these types of valves are comparable to quick exhaust valves.
This type of piston valve is also sometimes referred to as a back-pressure valve.
A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. Brass instruments are also called labrosones or labrophones, from Latin and Greek elements meaning 'lip' and 'sound'.
The cornet is a brass instrument similar to the trumpet but distinguished from it by its conical bore, more compact shape, and mellower tone quality. The most common cornet is a transposing instrument in B♭. There is also a soprano cornet in E♭ and cornets in A and C. All are unrelated to the Renaissance and early Baroque cornett.
The French horn is a brass instrument made of tubing wrapped into a coil with a flared bell. The double horn in F/B♭ is the horn most often used by players in professional orchestras and bands, although the descant and triple horn have become increasingly popular. A musician who plays a horn is known as a horn player or hornist.
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be transformed by a connecting rod and crank into rotational force for work. The term "steam engine" is most commonly applied to reciprocating engines as just described, although some authorities have also referred to the steam turbine and devices such as Hero's aeolipile as "steam engines". The essential feature of steam engines is that they are external combustion engines, where the working fluid is separated from the combustion products. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle. In general usage, the term steam engine can refer to either complete steam plants, such as railway steam locomotives and portable engines, or may refer to the piston or turbine machinery alone, as in the beam engine and stationary steam engine.
An actuator is a component of a machine that produces force, torque, or displacement, usually in a controlled way, when an electrical, pneumatic or hydraulic input is supplied to it in a system. An actuator converts such an input signal into the required form of mechanical energy. It is a type of transducer. In simple terms, it is a "mover".
The valve trombone is a brass instrument in the trombone family that has a set of valves to vary the pitch instead of a slide. Although it has been built in sizes from alto to contrabass, it is the tenor valve trombone pitched in B♭ an octave lower than the trumpet which has seen the most widespread use. The most common models have three piston valves. They are found in jazz and popular music, as well as marching bands in Europe, where they are often built with rotary valves and were widely used in orchestras in the 19th century.
Steam power developed slowly over a period of several hundred years, progressing through expensive and fairly limited devices in the early 17th century, to useful pumps for mining in 1700, and then to Watt's improved steam engine designs in the late 18th century. It is these later designs, introduced just when the need for practical power was growing due to the Industrial Revolution, that truly made steam power commonplace.
A rotary valve is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. The common stopcock is the simplest form of rotary valve. Rotary valves have been applied in numerous applications, including:
An automatic lubricator is a device fitted to a steam engine to supply lubricating oil to the cylinders and, sometimes, the bearings and axle box mountings as well. There are various types of automatic lubricator, which include various designs of displacement, hydrostatic and mechanical lubricators.
An air pump is a pump for pushing air. Examples include a bicycle pump, pumps that are used to aerate an aquarium or a pond via an airstone; a gas compressor used to power a pneumatic tool, air horn or pipe organ; a bellows used to encourage a fire; a vacuum cleaner and a vacuum pump. All air pumps contain a part that moves which drives the flow of air. When the air gets moved, an area of low pressure gets created which fills up with more air.
A pneumatic control valve actuator converts energy into mechanical motion. The motion can be rotary or linear, depending on the type of actuator.
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. This enables the direct control of flow rate and the consequential control of process quantities such as pressure, temperature, and liquid level.
A potato cannon, also known as a potato gun or potato launcher, is a pipe-based cannon that uses air pressure (pneumatic), or combustion of a flammable gas, to fire projectiles, usually potatoes. A simple design consists of a pipe sealed on one end, with a reducer on the other end to lower the diameter of the pipe, which has the corresponding lower-diameter pipe attached to it, called the barrel. Generally, the operator loads the projectile into the barrel, then utilizes a fuel or air pressure to propel the projectile out of the cannon.
The first recorded rudimentary steam engine was the aeolipile mentioned by Vitruvius between 30 and 15 BC and, described by Heron of Alexandria in 1st-century Roman Egypt. Several steam-powered devices were later experimented with or proposed, such as Taqi al-Din's steam jack, a steam turbine in 16th-century Ottoman Egypt, Denis Papin's working model of the steam digester in 1679 and Thomas Savery's steam pump in 17th-century England. In 1712, Thomas Newcomen's atmospheric engine became the first commercially successful engine using the principle of the piston and cylinder, which was the fundamental type of steam engine used until the early 20th century. The steam engine was used to pump water out of coal mines.
A plunger pump is a type of positive displacement pump where the high-pressure seal is stationary and a smooth cylindrical plunger slides through the seal. This makes them different from piston pumps and allows them to be used at higher pressures. This type of pump is often used to transfer municipal and industrial sewage.
Brass instrument valves are valves used to change the length of tubing of a brass instrument allowing the player to reach the notes of various harmonic series. Each valve pressed diverts the air stream through additional tubing, individually or in conjunction with other valves. This lengthens the vibrating air column thus lowering the fundamental tone and associated harmonic series produced by the instrument. Valves in brass instruments require regular maintenance and lubrication to ensure fast and reliable movement.
A horn is any of a family of musical instruments made of a tube, usually made of metal and often curved in various ways, with one narrow end into which the musician blows, and a wide end from which sound emerges. In horns, unlike some other brass instruments such as the trumpet, the bore gradually increases in width through most of its length—that is to say, it is conical rather than cylindrical. In jazz and popular-music contexts, the word may be used loosely to refer to any wind instrument, and a section of brass or woodwind instruments, or a mixture of the two, is called a horn section in these contexts.
The German horn is a brass instrument made of tubing wrapped into a coil with a flared bell, and in bands and orchestras is the most widely used of three types of horn, the other two being the French horn and the Vienna horn. Its use among professional players has become so universal that it is only in France and Vienna that any other kind of horn is used today. A musician who plays the German horn is called a horn player. The word "German" is used only to distinguish this instrument from the now-rare French and Viennese instruments. Although the expression "French horn" is still used colloquially in English for any orchestral horn, since the 1930s professional musicians and scholars have generally avoided this term in favour of just "horn". Vienna horns today are played only in Vienna, and are made only by Austrian firms. German horns, by contrast, are not all made by German manufacturers, nor are all French-style instruments made in France.
Étienne-François Périnet was a French instrument maker, best known for his development of an early piston valve system for brass instruments.
