Adjustable Flow Splitter *

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Corey Byrd
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1 Adjustable Flow Splitter * *Patent Pending Analytical Scientific Instruments Adjustable metering valve enables precise direct control over split ratios. Fluid resisr technology eliminates tedious adjustments capillary tubing change split ratios. Easy use interchangeable fluid resisrs create a wide range of split ratios. Split ratios are stable and reproducible. Rugged stainless steel ( ) and PEEK ( ) metering valve design permits operating pressures 5,000 PSI. ASI splitter technology can be applied all applications where a controlled, reproducible split ratio is required including LC/MS, flow fractionation, pre/post column flow splitting, and capillary chromagraphy. Create split ratios from 1:1 20,000:1. Low dead volume. 0.5 microliter delay volume on capillary side. Replaceable inlet filter prevents clogging. ASI Adjustable Flow Splitters make it easy create split ratios from 1:1 up as high as 20,000:1. Because the Adjustable Flow Splitter incorporates a metering valve, split ratios can be changed frequently with flow changes that are stable and reproducible. The model Adjustable Flow Splitter can be used for isocratic or gradient applications. Running gradients with solvents of different viscosities may result in a reproducible change the split ratio. The model Adjustable Flow Splitter will create split ratios that are not affected by changes in solvent viscosity or pressure. Split ratios are created by two fluid resisrs that form a parallel flow path. The low flow rate stream passes through a fixed resisr cartridge, while the high flow rate stream passes through an adjustable fluid resisr (metering valve). The ratio of these two resisrs creates the split flow ratio. The resulting ratios are stable and repeatable. Because of the rugged design, the split ratio repeatability is +/- 1% of setting, and unlike alternative splitter valves or tees, will not be affected by actions that effect input flow such as turning the pump off and on, or pressure spikes. To understand how the Flow Splitter works it helps look at a diagram of the fluid resisrs in relation the flow paths and how a split ratio is calculated. Input Flow - Q Resisr - L1 Low Flow Rate - Q2 High Flow Rate - Q1 L1 L2 R = Fixed fluid resisr (resistance value varies depending on cartridge rating) = Adjustable fluid resisr (metering valve) = Split ratio = Q1/Q2 Resisr - L2-1 -

2 Since the flow rate is indirectly proportional resistance, changing the resistance in either flow path results in a change the split ratio. Changing resistance is accomplished by adjusting the metering valve or exchanging the fixed fluid resisr cartridge with a resisr cartridge that has a different resistance rating. Adjusting the metering valve is analogous adjusting capillary tubing length on other flow splitters. Split ratios are increased by turning the adjustment knob clockwise, and decreased by turning the knob counter clockwise. Total dynamic range of the analytical metering valve without a resisr cartridge is 0 5,000 PSI at 1.0 ml/min. with water. The Prep range metering valve without resisr cartridge has a range of 0 1,000 PSI at 20 ml/min. with water. Because of the tight design lerences, it is easier adjust the splitters under pressure and with flow. The Adjustable Flow Splitter can be configured within the HPLC system for either post column flow splitting, or pre-column splitting. Input Flow (from pump) Replaceable Inlet Filter Adjustment Knob (controls adjustable resisr) ASI Split Flow Out (High Flow Rate) Split Flow Out (Low Flow Rate) Adjustable Resisr Resisr Cartridge Model Adjustable Flow Splitter The model Adjustable Flow Splitter has a convenient mounting bracket and hand adjustment knob control the split ratio. The split ratio may be affected (+-5%) by changes in fluid viscosity or pressure, but will change reproducibly. Applications include isocratic or gradient methods where a reproducible change in the split ratio is acceptable. Changes due viscosity and pressure will be small below approximately 2,000 PSI. At higher pressures the change in split ratio will be greater. If this change is unacceptable, consideration should be given the Stainless Steel model (Model ). Model Adjustable Flow Splitter The model Adjustable Flow Splitter is also mounted on a bracket for easy handling. The split ratio is adjusted by turning an adjustment nut (wrench included). Split ratios are not affected by changes in solvent viscosities or pressure, which makes this product suitable for gradient applications as well as isocratic. Other applications include SFC/MS, where large viscosity changes may be encountered during the gradient run

Adjustable Flow Splitter PEEK Model 600-1000 Adjustable Flow Splitter SS Model 600-2000 Selecting the Optimum Adjustable Flow Splitter Pre-column Flow Splitting Pre-column splitting is used for

3 Adjustable Flow Splitter PEEK Model Adjustable Flow Splitter SS Model Selecting the Optimum Adjustable Flow Splitter Pre-column Flow Splitting Pre-column splitting is used for micro, capillary, and nano HPLC applications, where the flow from the pump is split from analytical flow rates down microliter or nanoliter flows. It is important note that even though the split ratio created by the splitter valve will remain constant, the split ratio will change when a capillary column is installed. This is due the added resistance on the low flow rate channel from the column. This added resistance must be facred in when the split ratio is calculated and before a splitter valve is selected. Please contact ASI if you need assistance. Also, if the delay volume of the capillary column is large enough allow a significant solvent gradient exist in the column, then the viscosity in the column will not be the same as in the resisr inside the splitter, and this may begin affect the split ratio. Of course, this will only be a facr when running a gradient with solvents of different viscosities. Both of these effects on split ratio are repeatable, and will not affect the retention time reproducibility. However, these effects can be reduced by maximizing the resisr value on the low flow rate channel. Post-column Flow Splitting Post-column splitting is fairly straight forward. Like pre-column flow splitting, any significant additional pressure (resistance) down stream from the splitter may affect the split ratio. Post-column devices also contribute chromagraphic dispersion so care must given connecting tubing and fittings, especially at low flow rates

4 Calculate Split Ratio The split ratio R can also be determined from the input flow rate Q and the capillary output flow rate Q2 that is required: R = (Q- Q2) /Q2 R Q Q 2 : Split ratio : Input flow rate : Low flow rate channel Input Flow - Q Resisr - L1 Low Flow Rate - Q2 High Flow Rate - Q1 L1 L2 R = Fixed fluid resisr (resistance value varies depending on cartridge rating) = Adjustable fluid resisr (metering valve) = Split ratio = Q1/Q2 Resisr - L2 Use the back pressure vs. split ratio charts on page 7 & 8 select an Adjustable Flow Splitter that will provide the desired range of split ratio and back pressure. These charts correspond several flow rates and solvent systems. The back pressure is directly proportional flow rate and viscosity. Note: To calculate flow rate through the low flow rate channel, back pressure and resisr value, use the following relation Q2 = ( P/R)V Where Q2 is the low flow rate channel, ml/min. P R V = back pressure generated by splitter valve, PSI = resisr value, as stated on label (PSI/mL/min.) = Viscosity, Centipoise Configuring the Adjustable Flow Splitter for Cusm Split Ratio Ranges A variety of resisr cartridges can be ordered from ASI configure the Adjustable Flow Splitter for split ratios other than those listed above. Please contact technical service at for assistance in selecting the correct resisr cartridges. We will gladly assist you in determining the best splitter configuration for your application

5 Ordering Information Model Adjustable Flow Splitter Valve, Prep range, 5 ml/min. 40 ml/min. input flow These splitter manifolds will produce under 1,000 PSI backpressure with water at 20.0 ml/min. The backpressure will decrease in direct proportion a decrease in flow rate. Flow rates higher than 40.0 ml/ min. can be used, but may result in higher pressures. Split Ratio Range Valve, Prep, with -00 resisr cartridge Valve, Prep, with -01 resisr cartridge Valve, Prep, with -02 resisr cartridge Valve, Prep, with -03 resisr cartridge 500:1 20,000: 100:1 4,000: 50:1 500: 1:1 100: Valve, Analytical range 0.1 ml/min. 10 ml/min. input flow These splitter manifolds will produce under 5,000 PSI backpressure with water at 1.0 ml/min. The backpressure will decrease in direct proportion a decrease in flow rate. Flow rates higher than 1.0 ml/ min. can be used, but may result in higher pressures. Split Ratio Range Valve, Analytical, with -01 resisr cartridge Valve, Analytical, with -03 resisr cartridge Valve, Analytical, with -04 resisr cartridge Valve, Analytical, with -06 resisr cartridge 50:1 1,000: 15:1 250: 4:1 100: 1:1 20: Model Adjustable Flow Splitter Valve, Prep range, 5 ml/min. 40 ml/min. input flow These splitter manifolds will produce under 1,000 PSI backpressure with water at 20.0 ml/min. The backpressure will decrease in direct proportion a decrease in flow rate. Flow rates higher than 40.0 ml/ min. can be used, but may result in higher pressures. Split Ratio Range Valve, Prep, with -00 resisr cartridge Valve, Prep, with -01 resisr cartridge Valve, Prep, with -02 resisr cartridge Valve, Prep, with -03 resisr cartridge 500:1 20,000: 100:1 4,000: 50:1 500: 1:1 100: - 5 -

6 Model Adjustable Flow Splitter continued Valve, Analytical range, 0.1mL/min. 10 ml/min. input flow These splitter manifolds will produce under 5,000 PSI backpressure with water at 1.0 ml/min. The backpressure will decrease in direct proportion a decrease in flow rate. Flow rates higher than 1.0 ml/ min. can be used, but may result in higher pressures. Split Ratio Range Valve, Analytical, with -01 resisr cartridge Valve, Analytical, with -03 resisr cartridge Valve, Analytical, with -04 resisr cartridge Valve, Analytical, with -06 resisr cartridge 50:1 1,000: 15:1 250: 4:1 100: 1:1 20: Resisr Cartridge Resisr cartridge Resisr cartridge Resisr cartridge Resisr cartridge Resisr cartridge Resisr cartridge Inlet Filter Inlet Filter, 2 micron x.188 dia. pkg 5, 10µL volume $ Inlet Filter, 2 micron x.125 dia. pkg 5, 4µL volume Inlet Filter, 2 micron x.063 dia. pkg 5, 1µL volume standard for Prep range $50.00 standard for Analytical range $ Straight thru hole, No filter $

7 Back pressure vs Split ratio for water at 1.0 ml/min. / and Analytical range Back pressure (psi) Split ratio Back pressure vs Split ratio for water at 20mL/min. / and Prep range Solvent viscosities for common HPLC solvents (centipoise at 20 C) Back pressure (psi) Hexane Acene Acenitrile Methylene Chloride Methyl Ethyl Kene Methanol Tetrahydrofuran Toluene Water Propanol 2 Butanol 1 Butanol Split ratio Note: To find back pressure for other solvents use the following equation. P = P B * V * Q P B : the back pressure from chart : solvent viscosity centipoise Q : the flow rate, ml/min. V To order call

8 Back pressure vs Split ratio for 50/50 ACN/water at.200 ml/min. / /2000 Analytical range Back pressure (psi) Split ratio Back pressure vs Split ratio for 50/50 ACN/water at.500 ml/min. / /2000 Analytical range Back pressure (psi) Split ratio To order call Rev. 4/18/02

Fixed Flow Splitter *

Fixed Flow Splitter * Fixed Flow * *Patent Pending Analytical Scientific Instruments Fluid resistor technology eliminates tedious adjustments to capillary tubing to change split ratios. Easy to use interchangeable fluid resistors