Holes or ports in the body line up with the pipe in which the valve is installed. The plug is attached to a handle so that the plug can be turned within the body. A passage is bored through the plug. When the valve is in the open position, the passage in the plug lines up with the inlet and outlet ports of the body, thus allowing fluid to flow through the valve. When the plug is turned in the body, the solid part of the plug blocks the ports and thus prevents the flow of fluid.
Plug valves provide a positive shut -off and are suitable for throttling applications.
They present a minimum flow resistance when in the open position. Provide two examples of each . On the pump curves we saw that at max pressure there was no flow, and at no pressure there was max. Use the diagram on the next page to fill in below. LP Turbine 9.