A quarter turn valve, having a plug which can be turned to move its ports relative to the body seat ports to control the flow of fluid. The closure element is usually a tapered plug having a rectangular port.
Plug valves may take the following forms:
(i) Non-lubricated plug valve which can incorporate mechanical design feat-ures to reduce friction between the piug face and body seat ports.
(ii) Lubricated plug valve which in-corporates design features whereby lubricant can be injected under pres-sure to reduce friction between the plug face and body seat ports.
TYPES OF PLUG VALVES
A plug valve in which the plug is conical.
A plug valve in which the plug is cylindrical.