The metering pump is a positive displacement chemical dosing device with the ability to automatically vary its dosing capacity as process conditions dictate. The pump features a high level of repetitive accuracy and is capable of pumping a wide range of chemicals including corrosives or viscous liquids and slurries in hazardous environments including oil and gas installations, refineries and chemical processing plants. The pumping action is operated by a reciprocating piston which is either in direct contact with the process fluid or shielded from the fluid by a diaphragm.
Rotork multi-turn electric actuators precisely control the stroke of the pump, typically operating from a 4 -20mA control signal. The 1000 Series actuator from Rotork Process Controls is well suited to this application, featuring a compact mechanical design, 100% continuous modulating performance with high repeatability and resolution, manual override and a simple set-up programme.
The Rotork IQPro electric actuator is also used for this application. In addition to accurate pump stroking capabilities, the IQPro offers the benefits of non-intrusive set up and commissioning, data logging and valve diagnostics utilising Rotork’s popular IQ-Insight software.
The compact dimensions of Rotork electric actuator designs are a further assistance to the products’ adoption in metering pump applications, where the space available between the piston housings is often restricted.