Dosing pumpthe metering pump is a positive displacement chemical dosing device with the ability to vary capacity manually or automatically as process conditions require. It features a high level of repetitive accuracy and is capable of pumping a wide range of chemicals including acids, bases, corrosive or viscous liquids and slurries. The pumping action is developed by a reciprocating piston which is either in direct contact with the process fluid, or is shielded from the fluid by a diaphragm. Diaphragms are actuated by hydraulic fluid between the piston and the diaphragm. Metering pumps are generally used in applications where one or more of the following conditions exit: low flow rates in mlhr or gph are requiredhigh system pressure existshigh accuracy feed rate is demanded dosing is controlled by computer, microprocessor, dcs, plc, or flow proportioningcorrosive, hazardous, or high temperature fluids are handledviscous fluids or slurries need to be pumped