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Dionex LC20 Operator's Manual

Chromatography enclosure
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LC20 CHROMATOGRAPHY ENCLOSURE
OPERATOR'S MANUAL
© 1993 Dionex Corporation
Document No. 034859
Revision 02
September 1993

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  • Page 1 LC20 CHROMATOGRAPHY ENCLOSURE OPERATOR’S MANUAL © 1993 Dionex Corporation Document No. 034859 Revision 02 September 1993...
  • Page 2 Dionex Corporation, 1228 Titan Way, Sunnyvale, California 94088-3603.

  • Page 3: Table Of Contents

    Contents 1 • Introduction Overview ..... . . About This Manual ....Product Safety Information .
  • Page 4 Contents 2.4.3 Solenoid Interface ... . . 2-13 3 • Service and Maintenance Routine Operation ....3.1.1 Sample Loading .
  • Page 5 Contents Cleaning the Column Select Valve Slider ..Replacing Column Select Valve Port Face ..Servicing the Rheodyne Injection Valve ..A • Specifications A.1 Environmental ....A.2 Physical .
  • Page 6 Contents Doc. 034859-02 9/93...

  • Page 7: Introduction

    1 • Introduction Overview ..... . . About This Manual ....Product Safety Information .
  • Page 8 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 9: Overview

    1 • Introduction 1.1 Overview The LC20 Chromatography Enclosure is an integral part of the Dionex DX 500 Chromatography Systems. It can house the following system components, which must be ordered separately or as part of another module: Separator columns, optional guard columns, SRS...

  • Page 10: Product Safety Information

    LC20 Chromatography Enclosure Appendix A Specifications contains the LC20 specifications. Appendix B, Installation, describes the installation and interface necessary to place the LC20 into operation. 1.3 Product Safety Information This instrument was designed in conformance with the safety requirements set forth in IEC 1010 Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use.

  • Page 11: Description

    2 • Description Overview ..... . . Front Panel ..... . 2.2.1 Rheodyne Injection Valve .
  • Page 12 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 13: Overview

    The LC20 may be configured for optional dual-channel operation. It will then include a second Rheodyne injection valve and component panel. There is enough tubing in the LC20 Ship Kit (P/N 046300) to plumb two systems. The LC20 does not require power. Internal components are operated by the GP40/IP20 pump.

  • Page 14: Interior Layout

    LC20 Chromatography Enclosure 2.3 Interior Layout The interior of the LC20 is an insulated, passive chamber. It contains a slide-out panel for mounting components. Figure 2-1 illustrates the LC20 chassis. See Section B.2.1 for recommended stacking configurations. See Figure 2-2 for an illustration of the slide-out component panel.

  • Page 15: Component Panel

    2.3.1 Component Panel Components are mounted on the slide-out panel. The panel on the right side is standard in all LC20 enclosures. When a dual-channel module is ordered, an opposite panel is factory-installed on the left side (see Figure 2-2).

  • Page 16: Rheodyne Injection Valve

    LC20 Chromatography Enclosure The component panel has two slide releases to lock it in a fully closed (in) or open (out) position. Press the slide release at the upper horizontal edge of the panel to release the detent. The panel will lock at about three quarters of its total travel when you pull it out.

  • Page 17: Self-Regenerating Suppressor

    2 • Description The LC20 Ship Kit includes two accessories for the Rheodyne injection valves: a 25 µL gas-tight syringe (P/N 041389) and a 25 µL sample loop (P/N 042857). For more information about the valve, including important operating precautions, refer to the Rheodyne Valve Operator’s Manual (Document No.

  • Page 18: Column Select Valve

    The column select valve is controlled by the pump through a pair of air solenoids on the back of the LC20. The column select valve is not normally plumbed into the system.
  • Page 19 These bolts must be tightened evenly to provide uniform sealing pressure against the valve slider and ensure leak-free operation.. For valve maintenance information, refer to the Installation and Maintenance of the Dionex High Pressure Valve (Document No. 032678). Doc. 034859-02 9/93...
  • Page 20 LC20 Chromatography Enclosure The valve is operated by air pressure pushing against pistons inside the valve cap. The piston pushes a slider up and down inside the valve body. Applying pressure to the top piston pushes the slider down; applying pressure to the bottom piston pushes the slider up.

  • Page 21: Detector Cells

    90 in-oz while installing or removing the fittings. Use a wrench on the valve pressure bolt to prevent it from turning while loosening the fitting. Refer to Installation and Maintenance of the Dionex High-Pressure Valve (Document No. 032678) for additional information. 2.3.8 Detector Cells...

  • Page 22: Rear Panel

    LC20 Chromatography Enclosure 2.4 Rear Panel The rear panel provides installation space for air and valve connectors (see Figure 2-5). Figure 2-5. LC20 Rear Panel 2-12 Doc. 034859-02 9/93...

  • Page 23: Cell Cables

    2 • Description 2.4.1 Cell Cables The cables inside the LC20, which connect the detector cell to the CD20 Conductivity Detector or the ED40 Electrochemical Detector normally exit through service chase in the rear panel (see Figure 2-5). 2.4.2 Waste Line...
  • Page 24 LC20 Chromatography Enclosure 2-14 Doc. 034859-02 9/93...
  • Page 25 3 • Operation and Maintenance Routine Operation ....3.1.1 Sample Loading ....Shutdown .
  • Page 26 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 27: Routine Operation

    3 • Operation and Maintenance 3.1 Routine Operation Inside the Rheodyne injection valve, eluent flows through one of two paths depending on the position of the injection valve knob (see Figure 3-6). Figure 3-6. Injection Valve Schematic In the position, eluent flows in from the pump and out to the LOAD column without entering the sample loop.

  • Page 28: Sample Loading

    These techniques differ in accuracy, precision, and the amount of sample required. Refer to the Rheodyne valve Operating Instructions included in the LC20 Ship Kit before selecting a method for your application. Before filling the injection valve sample loop, set the...
  • Page 29 3 • Operation and Maintenance Figure 3-7. Drawing Sample Doc. 034859-02 9/93...
  • Page 30 LC20 Chromatography Enclosure 3. Loading sample through the waste line: To avoid the possible outgassing effects of using suction to draw the sample through the waste line, connect a luer fitting and sample-filled syringe in the end of the waste line. Connect the other end of the waste line into injection valve port #6.

  • Page 31: Shutdown

    3 • Operation and Maintenance 3.2 Shutdown If the LC20 will not be used for more than three days and if the column select valve is torqued for high pressure, reduce the torque on the pressure bolts to 90 in-oz to prevent possible damage to the valve.
  • Page 32 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 33: Troubleshooting

    4 • Troubleshooting Liquid Leaks ..... Excessive System Backpressure ..Inoperative Column Select Valve ..Column Select Valve Air Leaks .
  • Page 34 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 35: Liquid Leaks

    4 • Troubleshooting Use this troubleshooting guide to isolate and solve problems that may occur while using the LC20. If there is more than one possible cause, read the potential sources of the problem to determine which may be the most applicable. If the problem persists, call the nearest Dionex Regional Office.

  • Page 36: Excessive System Backpressure

    NOTE Use a torque wrench to evenly tighten pressure bolts for optimum leak-free operation. Refer to Installation and Maintenance of the Dionex Inert High Pressure Valve (Document No. 032678) for torque requirements. • A column select valve port is scratched.

  • Page 37: Inoperative Column Select Valve

    4 • Troubleshooting • Clogged column bed supports. Replace the bed supports as instructed in the column manual. • Columns are contaminated. Clean the columns (see Column Rejuvenation Procedures, Technical Note 2R, Document No. 032036). 4.3 Inoperative Column Select Valve •...

  • Page 38: Peak Ghosting

    LC20 Chromatography Enclosure 4.5 Peak Ghosting Ghosting is the appearance of extraneous peaks in a chromatogram. These may be late-eluting peaks from a previous injection or result from a contaminated valve or a poor sample loading technique. These peaks may co-elute with peaks of interest, resulting in non-reproducible peak heights.
  • Page 39 4 • Troubleshooting 2. Locate and eliminate any liquid leaks. • Contaminated or incorrect eluent. Remake the eluent using reagent grade chemicals and ASTM filtered Type I (18 megohms or 1 µS) grade deionized water. • Contaminated or degraded sample. Take appropriate precautions when preparing and storing samples to prevent contamination and degradation.
  • Page 40 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 41: Service

    5 • Service Introduction ..... Tube Fitting Installation ....Restriction in the Hydraulic System .
  • Page 42 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 43: Introduction

    Rheodyne injection valve, refer to the Rheodyne manual supplied in the LC20 Ship Kit. When ordering replacement parts, please include the model and serial number of your LC20. If possible, also provide the part numbers and, where applicable, the revision number of the items you are ordering.

  • Page 44: Restriction In The Hydraulic System

    LC20 Chromatography Enclosure 5.3 Restriction in the Hydraulic System A restriction in the hydraulic system will cause excessive system backpressure. 1. Begin pumping eluent through the system (including the columns) at the flow rate normally used. 2. Follow the appropriate hydraulic schematic (see Figures B-4 through B-6) and work backward through the system, beginning at the cell exit.

  • Page 45: Column Select Valve Air Leaks

    3. Make sure all valve pressure bolts are evenly tightened. Refer to Installation and Maintenance of the Dionex Inert High-Pressure Valve (Document No. 032678) for the torque requirements. Use caution as overtightening may break off the bolt in the valve body.

  • Page 46: Cleaning The Column Select Valve Slider

    LC20 Chromatography Enclosure 5. Unscrew the leaking cap from the valve body (Figure 2-3). Inspect the cap O-ring for cracks and replace if necessary (P/N 038650). 6. Press the disconnected air line (Step 4) against the small vent hole between ports 1 and 5. Activate the valve switch to apply air pressure against the slider.
  • Page 47 5 • Service 4. Unscrew one cap from the valve body. Be careful not to lose the cap O-ring. 5. Press the disconnected air line (Step 3) against the small vent hole between ports 1 and 5. Activate the valve switch to apply air pressure against the slider.

  • Page 48: Replacing Column Select Valve Port Face

    LC20 Chromatography Enclosure Switch in OFF or LOAD position (slider down): 1 → 4 and 2 → 3 5 → 8 and 6 → 7 Switch in ON or INJECT position (slider up): 1 → 2 and 3 → 4 5 →...

  • Page 49: Servicing The Rheodyne Injection Valve

    For optimal leak-free operation, a torque wrench can be used to evenly tighten pressure bolts. Refer to Installation and Maintenance of the Dionex Inert High-Pressure Valve (Document No. 032678) for torque requirements. Use caution as overtightening may break off the bolt in the valve body.
  • Page 50 LC20 Chromatography Enclosure 5-10 Doc. 034859-02 9/93...

  • Page 51: A • Specifications

    A • Specifications A.1 Environmental ....A.2 Physical ..... . . A.3 Hydraulics .
  • Page 52 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 53: Physical

    The column select valve option is installed at the factory but is not plumbed into the system. Tubing to plumb the LC20 for column select applications is included in the LC20 Ship Kit (P/N 046300).

  • Page 54: Insulation

    LC20 Chromatography Enclosure A.4 Insulation Dampening Dampens outside temperature variations by a factor of –5 to 10 over 10 minutes –2 to 4 over 60 minutes Doc. 034859-02 9/93...

  • Page 55: B • Installation

    B • Installation B.1 Facilities Required ....B.2 Installation Instructions ....B.2.1 Stacking Modules .
  • Page 56 LC20 Chromatography Enclosure Doc. 034859-02 9/93...

  • Page 57: Facilities Required

    B.1 Facilities Required Appendix A of this manual contains the complete LC20 specifications. The location selected to install the LC20 should also meet the following requirements: • A sturdy table or work bench with at least 15 cm (6 in) free space behind the module for connections and ventilation.

  • Page 58: Installation Instructions

    LC20 Chromatography Enclosure B.2 Installation Instructions A Dionex-trained representative will install the LC20 and other system modules for you. The instructions given here are for your reference. Contact the nearest Dionex Regional Office for assistance if you experience any difficulties during or after installation that are not addressed in this manual.

  • Page 59: Waste Lines

    B.2.2 Waste Lines Install the piece of 12.5-mm (0.5-in) OD tubing (P/N 035759) over the waste nipple in the lower left corner of the LC20 rear panel (see Figure 2-5). Make sure the opposite end of the line is inserted into a waste container below the level of the enclosure and that it is not bent, pinched, or elevated at any point (see Figure B-2).

  • Page 60: Waste Lines

    However, before cutting any tubing, be sure that it is long enough to allow servicing the system (e.g., you should be able to open the front door of the LC20 and slide the component panel out of the enclosure to its detent without putting stress on the tubing).

  • Page 61: Injection Valve Connections

    The system plumbing depends primarily on the detection mode. Consult the proper fluid schematic in Section B.2.5. The LC20 is plumbed with Dionex 10-32 ferrule fittings. If you need instructions on how to install ferrule fittings, refer to Installation of Dionex Ferrule Fittings (Document No.
  • Page 62 (or guard column, if installed). Refer also to Installation of Dionex Ferrule Fittings (Document No. 034213) included in the LC20 Ship Kit. 4. Connect the 25 µL sample loop (P/N 042857) between ports #1 and #4 of the Rheodyne injection valve. Other sample loop sizes are available, contact the nearest Dionex Regional Office for information.

  • Page 63: Detector Cells

    B • Installation B.2.5 Detector Cells External Cell When using a detector with a cell external to the LC20 (normally an optical detector), connect the outlet of the separator column or suppressor to the detector cell inlet (see Figure B-4). Route the tubing exiting the separator column or suppressor through one of the side slots on the LC20.

  • Page 64: Internal Cell

    Refer to the appropriate plumbing schematic in the following series (Figures B-4 through B-6) when installing a cell in the LC20. If the conductivity cell is installed inside the optional DS3 Detection Stabilizer, see the DS3 Detection Stabilizer Operator’s Manual (Document No. 034850).
  • Page 65 B • Installation Figure B-6. Electrochemical Cell Plumbing Schematic B-11 Doc. 034859-02 9/93...

  • Page 66: Column Installation

    LC20. 1. Before installing the separator columns, pump deionized water through the LC20 at 3 mL/min for 1 to 2 minutes to clear any air from the liquid lines. Activate injection each valve several times to make sure that no air is trapped in the hydraulic system.

  • Page 67: Srs Installation (Optional

    After consulting your column manual for any special requirements, install the columns in the LC20: a. Remove the end plugs from the separator column and store them in a safe place. You must reinstall the end plugs in the columns before placing the columns in storage.

  • Page 68: Solenoid Valve Connections To The Pump

    SRS, if necessary. Figure B-8. SRS Installation B.2.8 Solenoid Valve Connections to the Pump Connect air-actuated solenoid valves between pump and the LC20 for control of the column select and injection valves. Refer to the pump operator’s manual for installation instructions. B-14...
  • Page 69 Index Facilities required, B-3 Abnormal retention time, 4-6 Front panel, 2-3 Abnormal selectivity, 4-6 Air leaks, 4-5 Guard columns, 2-7 Cell cable connectors, 2-13 Column installation, B-12 Column select valve, 2-8 Columns Guard columns, 2-7 Hydraulic specifications, A-3 Separator columns, 2-7 Connectors Cell cable connectors, 2-13 Injection valve, 2-3, 2-6...
  • Page 70 LC20 Chromatography Enclosure Leak Control, B-6 Rear Panel, 2-12 Leak sensor, 2-7 Routine maintenance, 3-7 Liquid leaks, 4-3 Liquid Line Connections, B-6 Sample loading, 3-4 Separator columns, 2-7 Maintenance Service, 5-1 Abnormal retention time, 4-6 Shutdown, 3-7 Abnormal selectivity, 4-6...

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