<P> 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: </P> <Ul> <Li> Changing the pitch of brass instruments . </Li> <Li> Controlling the steam and exhaust ports of steam engines, most notably in the Corliss steam engine . </Li> <Li> Periodically reversing the flow of air and fuel across the open hearth furnace . </Li> <Li> Loading sample on chromatography columns . </Li> <Li> Certain types of two - stroke engines . </Li> <Li> Most hydraulic automotive power steering control valves . </Li> </Ul>

What is the purpose of a valve rotator