Chromatography Forum

The primary pumphead on channel B of our Infinity II binary pump will not come up to pressure during the pump leak rate test, it reaches barely 600 bar and stays there for 30 seconds before dropping. I just replaced the pumpseals and rear seal wash seals and everything is tight, no visible leak. I have also tried purging with IPA. What can I do next to troubleshoot?

First, make sure you have fully primed ALL channels with fresh solvent that is degassed (IPS preferred for testing). The pressure leak tests will fail if the system (pump) has trapped gas inside or needs service. This is the number one reason why testing fails.
Is the integrated degasser working? If the degasser is more than 3 years, then it is broken and due for replacement. They do not last long in these units are require regular servicing (not, the degassers are NOT serviced as part of any PM service. They are far too expensive for that and not part of most service plans).

If the system has been serviced, has a working degasser, fully primed, then Replace the pistons too. The pistons and seals are a set and should be replaced if a seal replacement alone does not re-establish function. It should also be stated that you must also be sure to Check the pump's check valves too, esp the outlet valves.

Thanks for your reply. Ultimately we had an Agilent technician come out to check it because absolutely no fault could be found in the pumphead - in the end he exchanged the entire thing saying it was defect.