Discussion Category: HPLC Pumps
Flow stoppage
I am having an issue with an intermittent air blockage in the pump head on this system. If i flush the pump head manually (as described in the manual) flow returns to normal for a short period of time than once again it will get air bubble entrained. No obvious leaks, system is well maintained (PMs with complete pumphead rebuild and replacement of all seals), dows not appear to be leaks in the vacuum degasser or solvent supply lines. Any thoughts?
Agilent was in and simply replaced the pumphead previously for the same issue, but did not resolve the issue.
Equipment: Agilent 1290 High Speed Pump
Reply byhz618211322
Based on the information provided, here are a few potential causes for the intermittent air blockage issue in the pump head of your Agilent 1290 High-Speed Pump:
Air ingestion during solvent priming: Ensure that the solvent lines are properly primed, and there are no air bubbles being introduced into the system during the priming process. Sometimes, improper priming can result in air being trapped in the pump head, leading to intermittent blockages.
Check valve malfunction: The check valves in the pump head are responsible for maintaining the flow direction and preventing backflow. If the check valves are not functioning correctly, they may allow air to enter the system. Verify that the check valves are clean, undamaged, and properly seated.
Degassing system issues: The vacuum degasser plays a crucial role in removing dissolved gases from the solvent before it reaches the pump. If there are issues with the degasser, such as leaks or improper functioning, it may introduce air into the system. Check the degasser for any leaks or malfunctions and ensure it is properly connected and functioning as intended.
Pump head seal issues: While you mentioned that the seals have been replaced during routine maintenance, it's worth checking if the pump head seals are in good condition and properly installed. Damaged or improperly installed seals can lead to air leakage and subsequent blockages.
Tubing and connection integrity: Inspect the tubing and connections throughout the system to ensure there are no leaks or loose fittings. Even a small air leak can cause intermittent air blockages.
System pressure fluctuations: Monitor the system pressure during operation to check for any irregularities. Fluctuations in pressure could indicate a problem within the pump or other components that could result in air entrapment.
Software or programming issues: Although less likely, it's worth verifying that the pump is operating with the correct settings and parameters. Ensure that the firmware and software versions are up to date.
If the issue persists after checking these potential causes, it may be beneficial to contact Agilent support again and provide them with detailed information about the problem and the steps you have already taken. They may have additional troubleshooting steps specific to your pump model or recommend on-site assistance.