Plug Valves:

A plug valve is a rotational motion valve used to stop or start fluid flow. A name is derived from the shape of the disk that resembles a plug. A plug valve is displays in Figure. The easiest form of a plug valve is the petcock. A body of a plug valve is machined to receive the cylindrical or tapered plug. The disk is a solid plug along with a bored passage at a right angle to the longitudinal axis of the plug.

Figure: Plug Valve

Within the open position, the passage within the plug lines up along with the inlet and outlet ports of the valve body. While the plug is turned 90° from the open position, a solid category of the plug blocks the ports and stops fluid flow.

Plug valves are available in either a lubricated or nonlubricated design and within a variety of styles of port openings by the plug as well as a number of plug designs.