rons321 wrote:
I agree with you. I am in the vacuum pump business, and I don't
understand why they can't make the pump a little more reliable. I can't
change the pump design myself, because it is certified the way it is.
It would be to costly to redesign it. If you need any vacuum pump
assistance, you can call me at 800-621-2531. Good luck to you. Ron

I would bet that any seal material or design that might work,
if it exists, would be so expensive that the pump price would rise just
enough that it would lose its competitive place in the market. Or if
there WAS a suitable seal, someone would have incorporated it by now
and marketed their pump as a superior, new and improved, longer lasting
oil- and solvent-proof design. Rapco HAS made small changes to their
pumps, things that weren't part of the original certification, such as
cooling fins, the inclusion of a small amount of salt in the vanes to
absorb a small amount of moisture and increase the vane life (low
humidity increases vane wear), and the flinger/oil drain idea for the
Continental vertical mount. Such changes lead me to believe that the
ideal shaft seal isn't available or affordable.

Dan