Duplex pumps

for precision mixing, diluting, and proportional metering

  • Duplex pumps
    Duplex pumps

STH and STQ Ratio:Matic Duplex pumps from Fluid Metering are suited for precision mixing, diluting, and proportional metering for OEM medical, analytical, and industrial instrumentation. The pumps consist of two FMI valveless pump heads direct coupled to a single variable speed drive, standardly a 23 frame stepper motor although other drive types can be used.

The displacement of each pump head is independently adjustable, and a variety of pump head sizes can be used in combinations to achieve dispensing ratios from 1:1 up to 500:1. Typically, each pump head is calibrated at the factory, locked in place, and will not require recalibration in the field, even after millions of cycles. Models are also available that can be adjusted in the field for applications that require frequent changes in mixing ratios or dispense volumes.

The duplex pumps feature FMI’s CeramPump valveless piston pump technology. This unique pump design utilizes one moving part, a rotating and reciprocating ceramic piston to accomplish both pumping and valving functions without valves. The piston and mated liner are made of dimensionally stable, sapphire-hard ceramics which ensure long term, drift-free accuracy of 1% or better for millions of maintenance-free cycles.