Piston valve

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.

[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.