Sleeved plug valves
A plug valve is a quarter-turn rotary motion manual valve and operates with the same principle used by ball valves. They feature cylindrical or conical plugs with one or more hollow passageways.
A plug valve is shaped like a cylinder or cone and can be rotated inside the valve body to control flow of fluids. The ports are typically at opposite ends of the body; therefore, the plug is rotated a fourth of a full turn to change from open to shut positions. This makes this kind of plug valve a quarter-turn valve.
Plug valves are an excellent option for many commercial and light industrial applications, including directional flow control, handling of gas or liquid fuels, regulating fluids with suspended solids, such as slurries, or handling low-pressure, low-temperature services. Amongst others, plug valves can be used for fluids with suspended solids.
Plug valves are commonly used in low-pressure low-temperature services, although some high-pressure-high-temperature designs also exists. Plug valves are high-capacity valves that can be used for directional flow control, even in moderate vacuum systems.
Even though both the plug valve and the ball valve are quarter-turn rotary valves, plug valves provide better flow control and are easier to maintain.