Piston seal access apparatus

摘要

A chemical pump includes an access sleeve positioned between a hydraulic driving cylinder and the chemical injection cylinder with a rod coupled between the hydraulic driving piston and the injection piston. The access sleeve structurally secures the driving cylinder to the injection cylinder and includes access ports through a sidewall thereof such that when the injection piston is withdrawn into the sleeve, the seals are accessible for replacement or other piston maintenance. According to another aspect of the invention, the diameter of the hydraulic piston is substantially greater than that of the injection piston.