Hallo Brandon,

if you use a Pfeiffer pump, than it is an almost very old pump. Modern pumps work without lubricants and have a ceramic support. The problem of lubricants is their viscosity. The manufacturer doesn't guarantee perfect function longer than a year. I think, the pump works longer and a short test makes no problem. You must control rotary speed and current. Whereas the accelaration period the current is very high and the pump switches off automatically, if a maximum power is exceeded. Nevertheless, if possible, I would change the lubricant.

The bigger problem could be the cooling (air or water). I assume, the pump is still water cooled. It is very important to test that a sufficiant high water flow is present. Otherwise the pump heats and destroyes.

Yours

R. Mitdank

Hi Rüdiger,

Thank you for this advice. I will probably change the lubricant soon and I have sufficient water cooling for this older pump. I didn't realize the newer ones didn't have "lubricant", though I just looked up the HiPace 80 manual and they do have an "operating fluid reservior" where the "lubricant reservoir" used to be, so I'm guessing the function is similar, even if they only recommend a change every 4 years now. We have a couple magnetic bearing turbos, which are nice, and avoid this issue.

All the best,

Brandon

Similar question to before, but for bearing replacements. Do people actually do this every 4 years as recommended without seeing any worrying symptoms? I've never sent a pump in for this, and I imagine this is >$1k service charge, but I also don't want a pump to shred itself because I didn't do it. Then again, if you start to get overheating and auto shutdowns in advance of something catastrophic, this could be used to indicate bearing replacement time prior to a serious problems. I've been working around turbo pumps for almost 10 years and been responsible for probably 12 turbos, and I've only ever seen a turbo shred itself once at an institution I was at, and that wasn't even my lab, and the turbo involved was comically old. Destroying a pump because of pushing maintenance intervals is a terrible outcome, but this honestly seems rare in my experience, and spending the cost of a new pump on bearing replacements every few years is also not ideal if you are quite unlikely to avoid destroying a pump. I understand the considerations are situational, e.g. if an unexpected pump failure in an industrial setting will lead to a huge daily monetary loss in revenue or productivity then skimping on pump maintenance is unwise, but if it means a couple weeks delay in an experiment and the failure is a super rare occurrence this is not such a big tradeoff.