Abstract: A self-retaining packing nut assembly may include a first piece having a first and a second section. The first section can be configured to engage diametrically an inside of a pump housing. The packing nut assembly may also include a second piece having a third and fourth section. The third section can engage diametrically an inner surface of the first piece. In addition, the second piece can be configured to axially adjust inside the first piece.

Abstract: An apparatus can include a housing, a plunger configured to reciprocate along an axis within the housing, and an internal fluid chamber disposed in the housing. A valve, having a valve base and a deformable seal, can also be included in the apparatus. The apparatus can further include a seat having an aperture therein. The valve is configured to move into and out of contact with the seat when the plunger reciprocates within the housing, based upon a fluid pressure in the internal flow chamber. In addition, an outer diameter of the deformable seal of the valve is less than an outer diameter of the seat.