Reciprocating piston pump with bleed passages

A reciprocating piston pump comprising:

• a tubular housing having a lower end positioned within a fluid source having an upper end for discharging fluid withdrawn from said source;
• a bottom check valve located at said lower end of said tubular housing for selectively allowing fluid to flow from said source into said tubular housing retaining fluid within said housing;
• a piston mounted within said tubular housing, said piston being reciprocatingly movable inside said tubular housing, said piston comprising:
• an open ended tube;
• a base plate having an opening therethrough and extending horizontally inside said open ended tube dividing said open ended tube into an upper high pressure reservoir and a low pressure chamber inside tubular housing;
• a plug for normally blocking fluid flow through said opening;
• and
• biasing means for applying a biasing force on said base plate tending to keep said base plate at a closed position where said base plate substantially blocks fluid flow from said upper high pressure reservoir to said low pressure chamber, said base plate having a peripheral surface, said peripheral surface being seated against said tubular housing when in said closed position, a plurality of grooves formed within said peripheral surface for allowing leakage of fluid from said high pressure reservoir into said low pressure chamber with said base plate closed, whereby said piston must be moved at a sufficient level of cycles per minute in order for pumping to occur.