GC 6890_actuator for gas sampling/switching valves does not work


We have one 6890 GC (G1540A), which has not been used for a while. The GC has 2 6-port valves, which are configurated for gas sampling and switching. The actuator driven by compressed air for these two valves does not seem to work well. Sometimes I heard about the air leaves from the outlet of the solenoid valve. Does this mean the valve has defect or is there any other problem to cause this? In addition, when we tried to operate the valve from the chemistation software, the actuator and/or valve have no response to the software. Anyone knows what the problem is for our GC? Thanks so much!


  • Hello  ,

    Sorry for the delay in response. Do you still need assistance with this or have you found a solution for your question? If you did have a solution, can you please share it so other users with similar issues can apply that to their case too?

    In terms of the problem description, it sounds to me like the valves might not be working. I am not all to familiar with switching valves, but I would imagine changing the valve is the first step. In terms of the Software, if you can operate all other parts of the GC fine, then you have good communication between GC and SW. Since only the valves are not responsive I would imagine it's, again, a problem with the valves themselves.

    Sometimes the SW gives you a more detailed description of the error, I would be curious what the error would be when that happens, and what type of Software you are using.

  • Try to actuate the valves at the front panel of the 6890.  Press [Valves], scroll to the desired valve, and then press [On] or [Off].  If the valves do not switch, check the compressed air supply.  It is the 1/4" plastic line and the supply pressure should be 50 psig.  Some air will vent out of the solenoid valves each time the valve switches on or off - this is normal.  If there is a constant hiss of air coming from the exhaust of the solenoid valve, there is an internal leak in either the solenoid or actuator.

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