Adjustable Flow Splitters

QuickSplit™ Adjustable Flow Splitters


  • Adjustable Flow Splitter allows direct real time control over split ratio optimization
  • Convenient for Chromatography methods development
  • Split flow rates can be maintained constant while incoming flow rates vary
  • Split flows are stable, reproducible, and are not affected by viscosity or pressure changes (Note: Split ratios may vary when used for pre-column gradient applications, but will not vary in post-column applications)
  • Split ratio ranges can be changed by replacing the fixed resistor element
  • Input flow rate from 0.25 mL/min. to 1L/min. available
  • Maximum 350 bar operating pressure
  • A graduated indicator rod tracks ratio settings, as documented in calibration data shipped with our splitters
  • Can be configured for Post-column or Pre-column applications

Unlike conventional splitters that use long lengths of capillary tubing, the ASI QuickSplit Adjustable Flow Splitter uses fluid resistors to achieve a wide range of split ratios.  The Adjustable Flow Splitter contains two fluid resistors that form parallel flow paths.  The low flow rate stream passes through a fixed resistor cartridge, while the high flow rate stream passes through an adjustable fluid resistor (metering valve).  The ratio of these two resistors creates the split flow ratio.  Because the Adjustable Flow Splitter incorporates a metering valve, split ratios may be adjusted by a factor of 20 (i.e.: 1:1 to 20:1) by simply turning a knob. This variable split ratio can be used with a fixed inlet flow to adjust low split flow rate by a factor of 10 (i.e.: 10 µL to 100 µL/min.). If a fixed low split flow is desired, inlet flow range may be varied by a factor of 10 (i.e.: 0.5 mL to 5 mL/min.).  Due to the rugged design, the split ratio repeatability is +/- 2% of setting, and unlike alternative splitter valves or tees, WILL NOT be affected by actions that effect inlet flow such as turning the pump off and on, or pressure spikes.

Typical uses for post-column flow splitting

Multiple detectors:

Split between 2 or more detectors such as mass spec and evaporative light scattering, UV, or IR.  This is especially important when one of the detectors is destructive, such as Mass Spectroscopy and ELS.


Reduce the flow rate from the column to a lower flow rate that the mass spec can work efficiently at. Chromatography methods are often using flow rates of 0.5 to 2 mL/min., which are too high for most mass spec.  Flow splitting is a way to reduce the flow rate down to flow rates suitable for the mass spec.  Although there are pumps that can deliver flow rates low enough to be compatible with mass spec, many practical reasons prevent Chromatographers from changing methods that are already proven to work at higher flow rates: reluctance to change to a different column from one that is familiar and accepted; FDA regulations and S.O.P’s that make any changes in methods burdensome; the ease of operation at higher mL/min. flow rates compared to µL/min. flow rates. Flow splitting allows the chromatographer to take a proven method that works at higher flow rates and quickly integrate mass spec or multiple detectors without re-developing the method.

Adjustable Flow Splitter General Description

Flow Splitter General Installation Instruction

Adjustable Flow Splitter Operation Instruction

Adjustable Flow Splitter Setting Low Split Flow Methods