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- Posts: 8
- Joined: Fri Aug 21, 2009 4:56 am
I have a few waters 1525u binary pumpswhich I recently did PMs on with the Waters specific PM kits. I used the appropriate seal extractor and installer tool; installed the check valves in correct orientation; set seals by running at 3k psi for 10 minutes. No visible leaks. But I am failing the ramp and decay test performing it according to waters protocol to a T. I do use 100% hplc grade methanol as called for in the procedure. I believe it is bad check valves; I used pin plugs to isolate pumps A and B and both failed miserably. I also eliminated the rheodyne valve by putting a pin plug in the outlet side of the pressure transducer.
I had some spare check valves and was able to get better results, but all ultimately failed to meet the < or = to spec of 15% pressure drop over 5 minutes. We could not even pass with one minute lapsed time.
Has anyone else experience bad check valves from waters? I have been servicing HPLCs for years and never had a problem with ramp/decay tests until working on these 1525 pumps. Sure, a bad check valve here and there, but nothing like this. Any suggestions would be appreciated.
I had some spare check valves and was able to get better results, but all ultimately failed to meet the < or = to spec of 15% pressure drop over 5 minutes. We could not even pass with one minute lapsed time.
Has anyone else experience bad check valves from waters? I have been servicing HPLCs for years and never had a problem with ramp/decay tests until working on these 1525 pumps. Sure, a bad check valve here and there, but nothing like this. Any suggestions would be appreciated.
