Valve guide and spring retainer assemblies are described for use in plunger
pump housings that incorporate structural features for stress-relief. These pump
housing structural features accommodate correspondingly-shaped valve guides and/or
spring retainers that are internally fixed in place using one or more non-threaded
spacers. Plunger pumps so constructed are relatively resistant to fatigue failure
because of stress reductions, and they may incorporate a variety of valve styles,
including top and lower stem-guided valves and crow-foot-guided valves, in easily-maintained
configurations. Besides securing valve guides and/or spring retainers, non-threaded
spacers may be shaped and dimensioned to aid in further reducing stress and to
improve volumetric efficiency of the pumps in which they are used.
