High pressure fluid system

A cartridge assembly module for a high pressure fluid end system comprising:

• a valve seat assembly having a discharge valve and defining a discharge passageway;
• a seal cartridge assembly having a plunger adapted for reciprocal movement therein, the valve seat assembly and seal cartridge assembly secured to one another with a fastener so as to form a single piece cartridge that is adapted for removal from a fluid end frame with both the valve seat assembly and seal cartridge assembly remaining secured to one another during the removal, the valve seat assembly and the seal cartridge assembly inseparable without removing the fastener;
• and
• a registration feature associated with at least one of the valve seat assembly and the seal cartridge assembly, the registration feature adapted to engage a corresponding registration feature of a loading chamber within which the cartridge assembly module is loaded so as to align and register the discharge passageway of the valve seat assembly in a preselected, generally non-rotatable configuration relative to another passageway defined by a discharge manifold proximate the single piece cartridge,
• whereby fluid communication between the discharge passageway of the valve seat assembly and the other passageway defined by the discharge manifold is established.

A method of servicing a high pressure fluid end system comprising:

• providing a fluid end system frame including a discharge manifold, a top portion defining a loading opening, and a rear portion including a frame retainer and defining a retainer opening;
• inserting a cartridge assembly module into the loading opening, the cartridge assembly module including a valve seat assembly having a discharge valve and a seal cartridge assembly having a plunger adapted for reciprocal movement therein, the valve seat assembly and seal cartridge assembly secured to one another to form a single unit;
• and
• projecting at least a portion of the seal cartridge assembly through the retainer opening;
• securing a retainer element to the frame retainer so as to force the cartridge assembly module into fixed, immovable engagement with at least one of the frame and the discharge manifold,
• maintaining the discharge manifold in a fixed position during said inserting, projecting and securing steps,
• whereby the cartridge assembly module is secured in a fixed orientation within the frame and in fluid communication with the discharge manifold.