Agilent 5973N Frustrating Leak
Posted: Tue Apr 17, 2018 4:29 pm
We recently acquired an Agilent 5973N MSD. I have made several attempts to operate the MSD, none of which have been successful. Here is a summary of the situation.
The MSD turbo pumps down to 100% within ~ 5 minutes. I have the transfer line capped with a blank ferrule for now. I received the MSD with a Pfeiffer foreline pump, and it made such loud noises that I connected an Edwards foreline pump instead. It runs fairly quiet. In any event, when I go to scan, it reports failure of the HED supply, and other times it simply reports "no peaks found" when I go to the manual tune tab. I have a 59864B gauge. Even though the turbo spins down to 100%, the gauge only reads around 4 x 10 -2 Torr. It should obviously be in the range of -5 or -6 Torr. It seems that there is a tremendous vacuum leak somewhere. I found it very difficult to believe that the manifold pressure could only be at -2 Torr when I don't have evidence of gurgling or leaking from the Edwards foreline pump (but I do hear gurgling from the Pfeiffer pump). I have another 59864B gauge, so I swapped it out in the event that my gauge was not reading correctly, and the second gauge also reads 4 x 10 -2 Torr. So, at least based on the gauge, the manifold is nowhere near where it needs to be. I swapped the HED supply yesterday, and the situation is still the same. It won't scan and reports HED supply error (most likely due to the high pressure).
Has anyone ever seen a 5973 MSD pump down to 100% turbo and only read 4 x 10 -2 Torr? I am surprised. I figured if the leak was this big, I would hear it, and/or the turbo would never be able to achieve 100% pump down.
In regards to finding the leak, I have removed the large o-ring around the manifold door several times now. No dust or lint is observed on it. I have worked with these MSDs before and have never had issues with pump down. I also cleaned the o-rings inside the front plate where the vent valve and PFTBA valve are located. Everything looks fine. I also completely removed the transfer line and inspected the o-ring that seals it. Looks good. I have also removed the clamps around the vacuum hose on both the turbo and foreline ends. All is secure.
The only places I haven't interrogated much are the ion gauge at the rear of the MSD. Feels very secure and I couldn't get the fitting to budge. The turbo looks to be seated fine underneath the MSD.
We did purchase this MSD used from a vendor we've used many times before with success. They pumped it down and tuned it just fine about 2 weeks ago.
If anyone has any suggestions, I'd love to hear them. Many thanks!
-Aaron
The MSD turbo pumps down to 100% within ~ 5 minutes. I have the transfer line capped with a blank ferrule for now. I received the MSD with a Pfeiffer foreline pump, and it made such loud noises that I connected an Edwards foreline pump instead. It runs fairly quiet. In any event, when I go to scan, it reports failure of the HED supply, and other times it simply reports "no peaks found" when I go to the manual tune tab. I have a 59864B gauge. Even though the turbo spins down to 100%, the gauge only reads around 4 x 10 -2 Torr. It should obviously be in the range of -5 or -6 Torr. It seems that there is a tremendous vacuum leak somewhere. I found it very difficult to believe that the manifold pressure could only be at -2 Torr when I don't have evidence of gurgling or leaking from the Edwards foreline pump (but I do hear gurgling from the Pfeiffer pump). I have another 59864B gauge, so I swapped it out in the event that my gauge was not reading correctly, and the second gauge also reads 4 x 10 -2 Torr. So, at least based on the gauge, the manifold is nowhere near where it needs to be. I swapped the HED supply yesterday, and the situation is still the same. It won't scan and reports HED supply error (most likely due to the high pressure).
Has anyone ever seen a 5973 MSD pump down to 100% turbo and only read 4 x 10 -2 Torr? I am surprised. I figured if the leak was this big, I would hear it, and/or the turbo would never be able to achieve 100% pump down.
In regards to finding the leak, I have removed the large o-ring around the manifold door several times now. No dust or lint is observed on it. I have worked with these MSDs before and have never had issues with pump down. I also cleaned the o-rings inside the front plate where the vent valve and PFTBA valve are located. Everything looks fine. I also completely removed the transfer line and inspected the o-ring that seals it. Looks good. I have also removed the clamps around the vacuum hose on both the turbo and foreline ends. All is secure.
The only places I haven't interrogated much are the ion gauge at the rear of the MSD. Feels very secure and I couldn't get the fitting to budge. The turbo looks to be seated fine underneath the MSD.
We did purchase this MSD used from a vendor we've used many times before with success. They pumped it down and tuned it just fine about 2 weeks ago.
If anyone has any suggestions, I'd love to hear them. Many thanks!
-Aaron