Rotary valve
Encyclopedia
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
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:
- Changing the pitch of brass instrumentBrass instrumentA brass instrument is a musical instrument whose sound is produced by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips...
s. - Controlling the steam and exhaust ports of steam engineSteam engineA steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...
s, most notably in the Corliss steam engineCorliss Steam EngineA Corliss steam engine is a steam engine, fitted with rotary valves and with variable valve timing patented in 1849, invented by and named after the American engineer George Henry Corliss in Providence, Rhode Island....
. - Periodically reversing the flow of air and fuel across the open hearth furnaceOpen hearth furnaceOpen hearth furnaces are one of a number of kinds of furnace where excess carbon and other impurities are burnt out of the pig iron to produce steel. Since steel is difficult to manufacture due to its high melting point, normal fuels and furnaces were insufficient and the open hearth furnace was...
. - Loading sample on chromatographyChromatographyChromatography is the collective term for a set of laboratory techniques for the separation of mixtures....
columnColumnA column or pillar in architecture and structural engineering is a vertical structural element that transmits, through compression, the weight of the structure above to other structural elements below. For the purpose of wind or earthquake engineering, columns may be designed to resist lateral forces...
s. - Certain types of two-stroke engines.
Use in brass instruments
Brass instrument
A brass instrument is a musical instrument whose sound is produced by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips...
s, rotary valves are found on horns
Horn (instrument)
The horn is a brass instrument consisting of about of tubing wrapped into a coil with a flared bell. A musician who plays the horn is called a horn player ....
, trumpet
Trumpet
The trumpet is the musical instrument with the highest register in the brass family. Trumpets are among the oldest musical instruments, dating back to at least 1500 BCE. They are played by blowing air through closed lips, producing a "buzzing" sound which starts a standing wave vibration in the air...
s, trombone
Trombone
The trombone is a musical instrument in the brass family. Like all brass instruments, sound is produced when the player’s vibrating lips cause the air column inside the instrument to vibrate...
s, flugelhorns, and tuba
Tuba
The tuba is the largest and lowest-pitched brass instrument. Sound is produced by vibrating or "buzzing" the lips into a large cupped mouthpiece. It is one of the most recent additions to the modern symphony orchestra, first appearing in the mid-19th century, when it largely replaced the...
s. Many European trumpet
Trumpet
The trumpet is the musical instrument with the highest register in the brass family. Trumpets are among the oldest musical instruments, dating back to at least 1500 BCE. They are played by blowing air through closed lips, producing a "buzzing" sound which starts a standing wave vibration in the air...
players tend to favor rotary valves.
Trombone
Trombone
The trombone is a musical instrument in the brass family. Like all brass instruments, sound is produced when the player’s vibrating lips cause the air column inside the instrument to vibrate...
F-attachment valves are usually rotary, with several variations on the basic design also in use, such as the Thayer axial-flow valve
Thayer Valve
The Thayer Axial-Flow Valve is a replacement for the traditional rotary valve found on trombones with F attachments. Invented by Orla Ed Thayer in 1976, it was the biggest advance in the design of the trombone since the rotary valve was added in the mid-19th century...
and Hagmann valve
Hagmann valve
The Hagmann Valve is a rotary valve for trombone that was developed by René Hagmann in the early 1990s. His intention was to address some of the problems with the popular Thayer Valve, in particular the maintenance issues caused by its relatively complex design....
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Joseph Riedlin is credited with the first use of rotary valves on brass instruments in 1832.
Use in industry
In industry, a rotary valve (which can also be called airlock) is often used to enter or extract material from two chambers with different pressure level.As part of the material exchange process, the valve is often used as a measuring or metering device.
Use in engine design
The rotary valve combustion engine possesses several significant advantages over the conventional assemblies, including significantly higher compression ratios and reduced complexity.Rotary valves have been used in several different engine designs. In Britain, the National Engine Company Ltd advertised its rotary valve engine for use in early aircraft, at a time when poppet valves
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...
were prone to failure by sticking or burning.
From the 1930s, Frank Aspin developed a design with a rotary valve that rotated on the same axis as the cylinder bore, but with limited success.
Kawasaki and others have also used rotary valves in two-stroke motorcycle engines, where the arrangement helps to prevent reverse flow back into the intake port during the compression stroke.
A US company has developed a spherical rotary valve for internal combustion engines which replaces the poppet valve system. This particular design is four-stroke, with the rotary valves operated by overhead shafts in lieu of overhead camshafts (i.e. in line with a bank of cylinders). The first sale of such an engine was part of a natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
engine-generator
Engine-generator
An engine-generator is the combination of an electrical generator and an engine mounted together to form a single piece of equipment. This combination is also called an engine-generator set or a gen-set...
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The 1980's MGN W12 F1 engine used rotary valves. The rotary valves are highly suitable for high reving engines such as those used in F1 on which traditional poppet valves with springs can fail due to spring resonance and where the desmodromic valve
Desmodromic valve
A desmodromic valve is a reciprocating engine valve that is positively closed by a cam and leverage system, rather than by a more conventional spring...
gear is too heavy, large in size and too complex to time and design properly.
Use in chromatography
Rotary valves are used for loading samples on columns used for liquid or gas chromatography. The valves used in these methods are usually 6-port, 2-position rotary valves.See also
- AirlockAirlockAn airlock is a device which permits the passage of people and objects between a pressure vessel and its surroundings while minimizing the change of pressure in the vessel and loss of air from it...
- Piston valvePiston valveA piston valve is a device used to control the motion of a fluid along a tube or pipe by means of the linear motion of a piston within a chamber or cylinder.Examples of piston valves are:...
- Rotary feederRotary feederRotary feeders, also known as rotary airlocks or rotary valves, are commonly used in industrial and agricultural applications as a component in a bulk or specialty material handling system. Rotary feeders are primarily used for discharge of bulk solid material from hoppers/bins, receivers, and...
- Itala cars