Abstract: A shaft seal arrangement includes a stuffing box defining a stuffing box central shaft opening extending around a shaft axis, packing arranged in the stuffing box around the central shaft opening, a packing gland defining a packing gland central shaft opening, and at least one adjuster assembly remotely operable to vary an engagement force between the packing gland and the packing. The adjuster assembly can be arranged around a packing gland stud and include an adjuster piston that is hydraulically operable to advance against the packing gland to vary the engagement force.