Benefits of V-Ring Chevron Type Packing?

[mechengr12]

Thanks in advance for your comments and advice. I currently have square braided PTFE packing on a cylindral slow rotating dryer that is not 100% cylindrical. We are having problems with packing (not as much anymore since we are on a more frequent greasing schedule) of the packing rolling up on itself and extruding itself. Does Chevron style packing offer a better seal as well as resistance to failure? Does Chevron style packing offer any benefits when the bore OD it sits on has a dip of as much as 3/8" (not perfectly round large diameter)?

 

[Artisi]

I would look at getting rid of the PTFE packing - never liked it and always considered it a source of problems - my experience is that it deadly on shafts and causes damage to the shaft. You probably need to rectify the shaft and start again with a good quality heavily lubricated impregnated cotton or similar type packing correctly installed with external lubrication.
A badly damaged shaft can't be made good by packing choice -

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[gerhardl]

Seems to me that it could be useful to either look into the sealing solutions for rotary joints, or rebuild and use a rotary joint. Note: also here the sealings are wearing parts, to be changed. Else I think Artisi is commenting to the point.