Plug Valve is the oldest known kind of valve. It is a commend assumption that the plug in the plug valve is taper (conic) . The fact is that there is a huge verity of the inside construction of a plug valve.
The plug valve is a 90 deg (quarter turn) operated valve.
The main purpose of a plug valve is isolation, and it will than either be fully open or fully closed
The secondary function of the valve is regulation which is achived by tapering the valve bore. This will reduce the aperture of the plug.
Range of application:
• Oil production
• Water injection
• Mud systems.
• Shut down valve on production
• Water injection and test manifold
• Between valve tree and separator.
• Change-over valve between filters.
• Meetering stations
Cylindrical without seats (integrated sets in the valve body)
Full bore “through conduit”
Venturi with reduced bore
As a rule plug valves are expected to be maintenance free, however for some valves maintenance is highly required to secure operation and avoid damage.