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:Changing the pitch of brass instruments.
Controlling the steam and exhaust ports of steam engines, most notably in the Corliss steam engine.
Periodically reversing the flow of air and fuel across the open hearth furnace.
Loading sample on chromatography columns.
Certain types of two-stroke and four-stroke engines.
Most hydraulic automotive power steering control valves.
Itala rotary valve engine (1912).
Italarotary valve cooling (1919).
Tuba with 4 rotary valves, by Yamaha
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'.
Six high brass instruments Left, from top: A reproduction baroque trumpet in D, a modern trumpet in B♭, a modern trumpet in D, a piccolo trumpet in B♭ (octave higher), and a flugelhorn in B♭. Right: a cornet in B♭.
A tenor horn (alto horn) in E♭, baritone horn in B♭, and euphonium in B♭
Brass instrument piston valves
Flugelhorn with three pistons and a trigger