PRESS FIT P029
This is the best way to insert a carbon-graphite face into a metal holder. The carbon will shear to conform to the holder’s irregular shape.
Some seal companies use a shrink fit, but irregularities in the outside diameters of the carbon and the inside diameter of its holder causes stress problems when the holder shrinks around the carbon face. If a carbon is inserted in this manner it must go through a series of stress relieving cycles to prevent the face from going out of flat.
Stress relieving can be accomplished by taking the assembly through a series of temperature changes or letting the assembly sit on a shelf and eventually “relax”.