Nonlubricated Plugs

There are two basic categories of nonlubricated plug valves: lift-type and elastomer sleeve or plug coated. Lift-type valves give a means of mechanically lifting the tapered plug slightly to disengage it from the seating surface to allow simple rotation. The mechanical lifting could be accomplished along with a cam or external lever.

In a general, nonlubricated, plug valve having an elastomer sleeve, a sleeve of TFE fully surrounds the plug. It is retained and locked in place through a metal body. This design results in a basic seal being maintained among the sleeve and the plug at all times regardless of position. A TFE sleeve is inert and durable to all but a few rarely encountered chemicals. That also has a low coefficient of friction and is, therefore, self-lubricating.