Frequency Control of Metering Pumps

When used as an integral part of a process system, a metering pump must be made responsive to a process variable. When the process variable is flow, measuring devices producing pulse outputs can be utilized to make a metering pump respond to the flow variation. A diaphragm or packed plunger metering pump is composed of a motor, a gearbox and a liquid displacement mechanism. Changes in the pump displacement can be accomplished by use of appropriate interface devices between the pulse transmitter and the pump.