Plug valves are valves with cylindrical or conically tapered "plugs" which can be rotated inside the valve body to control flow through the valve. The plugs in plug valves have one or more hollow passageways going sideways through the plug, so that fluid can flow through the plug when the valve is open. Plug valves are simple and often economical.

There are different kinds of plug valves, each adapted for different pressures and different usage.

1. Lubricated Type Lubricated plug valve could lubricate the plug or stem by itself when it is moving. It has oil rings in body to make easy to operate. It is usually metal seated.

2.Non- Lubricated Type Non-Lubricated plug valve could not lubricate the plug or stem when it is moving. The plug or the body is sleeved by lined by rubber or PTFE.