Inverted Taper Pressure Balanced Lubricated

[khalodee123]

what does Inverted Taper Pressure Balanced Lubricated valve mean

always i see this on a plug valve spec.

best regards

 

[JimCasey]

Normally a plug valve has a top-entry and the plug is tapered wider at the top. An inverted plug valve is inserted from the bottom, so there is a bottom flange AND a shaft seal. This can be made to balance the axial forces on the plug so it is not displaced by the process pressure. I assume you know the lubricated part, but in a lubricated plug valve a >SEALANT< is hydraulically injected to float the plug free of the body so it can turn. I highlighted "sealant" because it is more than a lubricant: it is specially formulated so that it neither is soluble nor reactive with whatever the process fluid is.

Maybe this link will work. If not, go to FLowserve.com, valves, and Nordstrom.

http://fcd.flowserve.com/valves/products/valve.jsp?pageid=NVA0009

Lubricated plug valves are used in refining, water and waste, and mining applications.

There are also NONlubricated plug valves. These have a tapered plug that nests into a (usually) tfe sleeve/liner in the body. These tend to be more useful in chemical applications. These are also in the Flowserve.com website under "Durco".