Chemical injector system for piston pumps

Claim 1

In combination with a positive-displacement piston pump of the type including a crank case housing in which is journaled a crank shaft having one or more eccentric lobes, a connected rod coupled to each of said one or more lobes, a cylinder block including one or more cylinders, said block being attached to said crank case housing, plunger means disposed in each of said one or more cylinders and joined to said connecting rod for reciprocating movement within said cylinders, a cylinder head fastened to said cylinder block and including a fluid inlet port and a fluid outlet port, intake valve means individually operatively associated with each of said cylinders for allowing a one-way flow of a first fluid from said inlet port to said cylinders only during a suction stroke of its associated plunger means, outlet valve means individually operatively associated with each of said cylinders for allowing a one-way flow of said first fluid from said cylinders only during a pressure stroke of its associated plunger means, and a plug for each of said intake valve means and outlet valve means for holding said intake valve means and said outlet valve means in place in said cylinder head, the improvement comprising: one of said plug means associated with a given intake valve means including injector valve means whereby that given intake valve means is held in place in said cylinder head while allowing a second fluid to be drawn into the cylinder associated with said given intake valve means during the suction stroke of the plunger means contained in that one cylinder.