The 500-E series offers a wide array of diaphragm metering pump is capable of pumping a maximum of 18 gallons per hour. Each diaphragm metering pump can generate a pressure rate of up to 1100 psi. The pumps are fabricated in several liquid end materials such as 316 stainless steel, Polyvinyl chloride and Kynar® fluorinated polymers. Integrated with a variable oil by-pass stroke adjustability that provides an optimum valve functionality over variable linkage structure. These pumps are incorporated with capacity regulators namely electric stroke length and variable speed drives.