Fluid end block and fluid end for a multiplex piston pump having multiple inlet passages

An apparatus, comprising:

• a fluid end block;
• a first set of multiple linear bores directed through the fluid end block in a primary direction, wherein each of the linear bores in the first set form a piston chamber;
• a second set of multiple linear bores directed through the fluid end block in a lateral direction, wherein each of the linear bores in the second set form a cross bore that intersects with one of the piston chambers, and wherein each cross bore has a fluid inlet end and a fluid outlet end;
• one or more outlet bores directed into the fluid end block in a longitudinal direction, wherein the fluid outlet end of each cross bore is intersected by one of the one or more outlet bores;
• a first inlet bore directed into the fluid end block in the longitudinal direction from a first end of the fluid end block, wherein the first inlet bore is a first blind bore that intersects with the fluid inlet end of a first subset of the cross bores;
• a second inlet bore directed into the fluid end block in the longitudinal direction from a second end of the fluid end block that is opposite the first end of the fluid end block, wherein the second inlet bore is a second blind bore that intersects with the fluid inlet end of a second subset of the cross bores, and wherein a portion of the fluid end block separates a bottom end of the first blind bore and a bottom end of the second blind bore;
• a plurality of inlet valve assemblies including, for each piston chamber, one of the inlet valve assemblies secured within the fluid inlet end of the cross bore that intersects with the piston chamber to allow one-way fluid flow into the piston chamber;
• and
• a plurality of outlet valve assemblies including, for each piston chamber, one of the outlet valve assemblies secured within the fluid outlet end of the cross bore that intersects with the piston chamber to allow one-way fluid flow out of the piston chamber.