A valve assembly having a dynamic stem seal assembly includes a valve stem for moving a valve member from a closed position to an open position, the valve stem extending through a stem opening of a valve assembly body and having an axis. A packing assembly seals between the valve stem and the stem opening. The packing assembly has a seal assembly circumscribing the valve stem at a portion of the valve stem with a reduced outer diameter. The packing assembly also has a packing retainer assembly releasably secured to the valve stem at the portion of the valve stem with the reduced outer diameter. The packing assembly is axially static relative to the valve stem.