U-SEALS
A packing in which the element has a "U"-shaped cross-section.
ULTIMATE ELONGATION
The maximum elongation prior to rupture.
UNBONDED FLASH
Flash which does not properly adhere to the mating material to which it is intended to be bonded.
UNCOMPRESSED HEIGHT
The height of a packing set or packing ring before being compressed in the stuffing box.
UNDER-CURE
A degree of cure less than desired.
UNIROTATIONAL SEAL
A seal, designed for applications having a single direction of shaft rotation.
UNITIZED SEAL
A seal assembly in which all components necessary for accomplishing the complete sealing function are retained in a single package.