Plug Ports:

An important feature of the plug valve is its simple adaptation to multiport construction. Multiport valves are hugely used. Their installation simplifies piping, and they give a more convenient operation than multiple gate valves. They also eliminate pipe fittings. A use of a multiport valve is totally depending upon the number of ports within the plug valve, eliminates the requirement of as several as four conventional shutoff valves.

Plug valves are generally used in non-throttling, on-off operations, particularly whereas frequent operation of the valve is essential. Those valves are not generally recommended for throttling service since, like the gate valve, a high percentage of flow change occurs near shutoff at high velocity. Therefore, a diamond-shaped port has been established for throttling service.