A fluid end assembly comprising a plurality of fluid end sections positioned in a side-by-side relationship. Each section comprises a housing containing a reciprocating plunger. One and only one packing seal is installed within the housing and surrounds and engages an outer surface of the plunger. A retainer compresses and holds the packing seal within the housing. The retainer is secured to the housing using a clamp, such that no threads are formed in the housing of the fluid end section and no threads are formed in the retainer.

A mechanical packing sealing assembly includes an axially movable pressure adjustment element having a main body that is sized and configured for seating within the recess formed in the stationary equipment. The main body can include a radially outwardly extending first flange element formed at a first end that is sized and configured for engaging with a radial surface of stationary equipment of a fluid regulating device and a radially inwardly extending second flange element formed at an opposed second end and forming a piston area for being exposed to a pressure of a process fluid in the stationary equipment. The second flange element can selectively apply an axial force to the packing assembly when coupled to the main body, and the pressure adjustment element is movable axially as a function of the pressure of the process fluid applied to the piston area.

Disclosed is a device for tensioning a stuffing box packing which abuts against a superordinate assembly which is to be sealed by the stuffing box packing and which, such as the stuffing box packing, does not belong to the tensioning device. The device comprises a stuffing box gland, which is designed and intended to abut against a free side of the stuffing box packing, and a plurality of tensioning elements, which are designed and intended to press the stuffing box gland against the stuffing box packing and thus the stuffing box packing against the superordinate assembly. A separate motor drive unit is associated with each of the tensioning elements.

A system for regulating an axial biasing force applied to a stacked set of packing elements mounted within stationary equipment, comprising a packing loading assembly for sealing a process fluid within the stationary equipment and for applying the axial biasing force to the packing elements via a pressurized fluid from a pressure regulator. The packing loading assembly includes a gland element for mounting to the stationary equipment by a plurality of gland bolts, and an external actuation subsystem for coupling to at least one of the plurality of gland bolts for applying an axial actuation force directly to the gland element in response to the pressurized fluid. The gland element in response to the axial actuation force applies the axial biasing force to the packing elements.