Replacing the needle seal and seal port tubing

Replacing the needle seal and seal port tubing
Topic LCI-USG-0180, Last Updated 11/08/2024

To prevent disruptions to your workflow, replace the needle seal and seal port tubing annually during the prescribed preventive maintenance (PM) schedule or any time the seal appears dirty, contaminated, or clogged. Also replace the seal any other time it is necessary to replace the needle.

Replacing the needle seal and the seal port tubing involves removing the following:

  • Wash station assembly
  • Locking nut that houses the needle seal
  • Existing needle seal
  • Existing seal port tubing (holds the locking nut) and attached to the wash station assembly
Warning: To avoid personal contamination with biologically hazardous or toxic compounds, wear clean, chemical-resistant, powder-free gloves when performing this procedure.
Warning: To avoid eye injury, use eye protection when performing this procedure.

Required tools and materials

  • Seal kit
  • Seal port tubing (Waters part name: Assy, Seat Port, SST, 0.007 ID)
  • Chemical-resistant, powder-free gloves
  • Protective eyewear
  • 7/16-inch open-end wrench (procedure requires two wrenches)
  • T10 TORX driver
  • T20 TORX driver

To replace the needle seal:

  1. Ensure that the system is powered-on.
  2. Open the sample compartment door and the fluidics compartment door.
  3. Remove any sample plates from the sample compartment.
  4. Move the sample needle into service position:
    1. Tap MAINTAIN > Service > Prepare to Replace the Needle.
  5. Using the T20 TORX driver remove the captive screw that secures the access panel, and then remove the panel.
    Figure 1: Captive screw on access panel
    Captive screw
  6. To lift the wash station assembly out of the wash station holder:
    Note: You will not remove the wash station assembly (rather, you will temporarily detach it from the holder).
    1. Locate the wash tubing and seal port tubing secured in the bottom three clips. Release the tubing from the three clips.
      Figure 2: Wash tubing and seal port tubing location in clips
      First wash tubing in clip
      Second wash tubing in clip
      Seal port tubing in clip
    2. Push down on the wash station assembly, and then rotate it clockwise to temporarily remove it from the wash station holder.
    Figure 3: Release the wash station assembly from the wash station holder
    Wash station assembly (inside the wash station holder)
    Wash station holder
  7. Lift the wash station assembly out of the wash station holder.
    Figure 4: Releasing the wash station assembly from the wash station holder
    Support sleeve
    Locking nut location (nut not visible)
    Slot
    Spring
    Wash station holder
    Seal port tubing in PEEK fitting (image shows tubing shorter than it actually appears)
    Seal port tubing in PEEK fitting (image shows tubing shorter than it actually appears)
    Requirement: Ensure that the locking nut remains seated inside the spring.
  8. Locate the locking nut attached to the bottom of the wash station assembly that houses the needle seal. To access the needle seal, remove the locking nut using two 7/16-inch open-end wrenches to ensure proper grip.
    Figure 5: Wrench placement locations to remove the locking nut
    Place one 7/16-inch open-end wrench here on the support sleeve
    Place the other 7/16-inch open-end wrench here near the locking nut (not visible)
  9. Lift the outer edge (or lip) of the locking nut. Tilt the locking nut to remove the needle seal, and then discard.
    Figure 6: Removing the needle seal from the locking nut
    Seal
    Locking nut (actual nut updated and shows no prongs)
    Seal port
  10. Waters recommends replacing the seal port tubing when you replace the needle seal. To remove the seal port tubing:
    1. Unscrew the tool-free fitting attached to the seal port tubing, and then remove one end of the seal port tubing from port 1 in the inject valve.
    2. Thread the seal port tubing through the locking nut, and then remove it.
      Figure 7: Seal port tubing removal
      Locking nut
      Seal port tubing
  11. Insert the replacement seal into the locking nut. The seal is keyed, ensuring its correct installation, as shown in the following two figures.
    Note: To prevent contaminating system components, wear clean, chemical-resistant, powder-free gloves, and work on a clean surface when replacing the seal.
    Note: The following image shows prongs, but the actual locking nut does not have prongs.
    Figure 8: Inserting replacement seal into the locking nut
    Smaller-diameter end
    Seal
    Notch
    Locking nut
    Seal port
    Figure 9: Seal notch location
    Seal
    Notch
    Seal cup
  12. Finger-tighten the locking nut into the bottom of the wash station assembly.
  13. Place the two 7/16-inch open-end wrenches on the washing station support sleeve, and then tighten.
    Note: To avoid damaging the seal port tube, do not excessively twist the tube.
    Figure 10: Wrench placement locations
    Place one 7/16-inch open-end wrench here on the support sleeve
    Place the other 7/16-inch open-end wrench here
  14. Ensure that the seal port tubing remains in line with the PEEK fitting in the support sleeve.
    Figure 11: Seal port tubing in PEEK fitting
    Seal port tubing in top PEEK fitting
    Seal port tubing in bottom PEEK fitting
    Support sleeve
  15. Slide the seal port tubing into the slot on the side of the housing.
    Figure 12: Sliding seal port tubing into the slot
    Support sleeve
    Locking nut location (nut not visible)
    Slot
    Spring
    Wash station holder
    Seal port tubing in PEEK fitting (image shows tubing shorter than it actually appears)
    Seal port tubing in PEEK fitting (image shows tubing shorter than it actually appears)
  16. Slide the support sleeve into the housing, ensuring that the fitting hole on the support sleeve aligns with the slot on the housing.
    Figure 13: Inserting support sleeve into the housing
    Fitting hole
    Slot
  17. Reinsert the tubing in the clips on the side of the sample compartment. For example, route the wash tubing and seal port tubing through the clips.
    Requirement: The tubing is secured to the wall and must not interfere with operation of the sample tray or the vertical motion of the wash port.
    Figure 14: Replace the wash tubing and the seal port tubing in the clips on the sample compartment wall
    First wash tubing in clip
    Second wash tubing in clip
    Seal port tubing in clip
  18. Screw the seal port tubing end into port 1 of the injection valve, and then use the 1/4-inch open-end wrench to tighten the fitting 1/4-turn beyond finger-tight.
    Figure 15: Attach the seal port tubing to the injection valve
    Port 1 on injection valve
  19. Reinstall the access panel, and then use the T20 TORX driver to tighten the single screw that secures the access panel to the front of the unit.
    Requirement: Ensure that the seal port tubing and sample needle tubing are routed through the gap in the access panel and that they do not cross each other.
  20. Close the sample compartment door and the fluidics compartment door.
  21. Tap COMMANDS > Reset to turn the motors back on and home the needle carriage.
  22. Complete the needle seal readiness test to verify that the needle seal works properly.

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To avoid risk of personal injury and to prevent damage to laboratory equipment, always operate your Waters products in accordance with the applicable operational and safety information, your organization’s standard operating procedures, and local regulations.

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