System channel primeing/purging

Hope i can make my problem understandable. So, Im working with a Waters e2695 (gray, and oldie), and it has 4 general eluent channels (A, B,C,D) and a fifth channel (with a green tube wrapped around the translucent tube). I call it system channel ;)... in it is a solution of 1:3 (ACN and water), and it is used for needle wash (and probably something else). Okey this is the intro.
How do i manually prime/purge it? Because there are some air bubbles, and if they get inside the needle, its gonna be bad news bears ( i think).
Thank you for reading this. 


  • Diag -> Prime NdlWsh

  • LMP
    This i also found, but it doesnt use the channel/tube i want. The option prime seal wash use that tube, but the chromatograph just clicks and the solution in the tube moves back and forth.
  • If you use prime seal wash does any liquid come out from that tube ?
  • MJS
    On the classic alliance 2695, the green line is the needle wash line with no frit at the end of the tubing, the clear is the seal wash line with a white frit at the end. 

    For the needle wash line, you typically want a high organic with something that your materials are highly miscible in, so a 1:3 ACN:Water may or may not be sufficient to prevent carryover.  As DavidHPLC indicated, you prime that on the system a few times.  The needle wash pump may need 2 to 3 cycles if completely dry.  This can be observed in your waste lines as the yellow line will sputter during this priming cycle.

    The seal wash line runs through the pump heads.  If you are only hearing a loud click noise and seeing the air bubbles twitch and not really move, then you have a little bit of work to do to really prime the line as that pump is not really powerful enough to draw in liquid if it is super dry.  The system guide, Waters doc# 71500269502, details this for the 2695, but basically, initiate the prime, then use a syringe to slowly feed solution into the tubing.  Once you've got a bit in there, pause the prime, put the line in your bulk solution (at a higher elevation than the pump), then resume the prime.  The air in the lines should clear easily enough with a little bit of time (gravity will help feed fresh solution through the line) and once the air in the pump is clear, the volume/tone of the clicking will be subdued significantly.  Just make sure you run it a couple minutes after the noise changes and observe no bubbles in the tubing running in/out the sides of the pump heads.