Troubleshooting Gas Flow Issues in a MULTIVAP and 116 N-EVAP || Organomation



August 16, 2022

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  • Contact Us: Troubleshooting Gas Flow Issues in a MULTIVAP and 116 N-EVAP If the gas flow in your MULTIVAP or 116 N-EVAP is not functioning as expected, there are a few simple troubleshooting steps you can take before calling a technician. These steps will help identify where the issue is, in case a replacement part is needed. General Troubleshooting First, check to see if you are getting optimal pressure from your gas source. The recommended pressure for MULTIVAPs and 116 N-EVAPs is 50-110 psi. Then, check that the gas flow is reaching the bath case. Disconnect the gas tube from the back of the unit, turn on the gas source, and confirm that there is flow. Reconnect the gas tube and verify that the flow meter is open, and the gas switch and toggle switches are on. Check for missing needles or luer plugs on all positions. An open sample position without a needle or luer plug will allow gas to escape, reducing flow to the rest of the samples. Pressure Regulator To check the instruments’ built-in pressure regulator, turn off the gas switch but leave the gas source on and connected. If the pressure gauge reads between 20-30 psi, the regulator is working. If not, it may need to be adjusted. To do so, locate the knob on the top of the unit labelled “flowmeter”. Rotate it clockwise and observe the pressure gauge for movement. The gauge should go up when the knob is turned clockwise and down when it’s turned counterclockwise. If the gauge responds, set it between 20-30 psi, turn on the gas switch, and re-check the flow. If it doesn’t respond, the pressure regulator or gauge most likely needs to be replaced. Flow Meter To check the flow meter, turn on the gas switch and rotate the flow meter dial counterclockwise. This should open the valve, causing the ball to respond. If it doesn’t respond, unplug the tube connected to the flow meter and check for gas flow. If there’s no gas flow, the flow meter is likely not the issue. If there is gas flow, check that the ball is not stuck. To do this, disconnect the flow meter from the instrument and flip it upside-down. If the ball doesn’t move, the flow meter needs to be replaced. Gas Switch For baths manufactured before 2019, check that the gas switch is not stuck internally. Unplug your instrument and let cool before handling. Remove the nitrogen distribution assembly and flow meter. Open up the control box and locate the gas switch. When flipping the switch, the top post should retract as shown in the left picture. If it doesn’t retract as shown in the right picture, the switch is defective. Contact Organomation for further repair instructions. Solenoid Listen for any leaks or buzzing noises coming from the bath case. A buzzing noise may indicate a bad solenoid that needs to be replaced. To check the solenoid, open up the control box if you have not done so already. Locate the solenoid and its bracket towards the back of the box. Look for any disconnected tubing or wires. If all the connections seem to be secure, confirm if the solenoid is being energized. To check this, keep the control box open and upside down. Make sure the gas switch is turned to manual and the power switch is turned on. Be very careful not to shock yourself. Plug in your instrument and listen for a click coming from the solenoid. If you don’t hear a click as the solenoid is energized, then it is bad and needs to be replaced. If you were not able to identify the cause of your gas flow issue with these troubleshooting steps, the Organomation team can assist you further. Please reach out to or call us at 978-838-7300.

    Analytical TechniquesChromatographyEnvironmental ScienceMass Spectrometry

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