However, it must be remembered that when any finish is polished a certain amount of plating is removed and that eventually this loss of finish will require the replating of the instrument. This loss of plating is more pronounced in the silver and gold plated instruments. Brass instruments have two types of valves available. Piston valves operate just as one would expect. They go down and up by means of a spring.
Rotary valves rotate from left to right and are now the most popular valve type found on tubas.
Neither type has advantages or disadvantages over the other. It is a personal choice to be made by the player. The placement of the valves may present come concern amongst players. In general, most players prefer the front action style, although depending on the manufacturer, some tubists will find themselves using the top action. Neither system is preferable over the other, although there are those who believe that the piston valve is more fussy and requires more care because it is not enclosed in the same way as the rotary valve.