Vacuum Pumps 101

May I present to you the humble vacuum pump:

Credit: Ideal Vacuum

Credit: Ideal Vacuum

We chemists tend to not give them much thought, which is a shame seeing in that we work with them daily.  Much of our work depends on being able to lower the pressure of a system for whatever reason.  Want to evaporate solvent?  Your membrane diaphragm pump has your back.  Want to distill an irritatingly high-boiling off-yellow mixture to your pristine colorless product?  Look no further than your trusty rotary vane pump.  Need to shoot your compound onto a mass spec?  The instrument’s turbo pump creates the ultra high vacuum environment required for accurate analysis.

I could go on.

Despite the ubiquity and utility of vacuum pumps in the chemistry lab, the trend I’ve noticed is that most workaday chemists know little to nothing about how they work and how to take care of them.

[Screaming Internally]

“Steve, this says the last time you changed the pump oil was April 2014.”

As a result of this ignorance around pumps, I propose all chemistry degree programs, at both the graduate and undergraduate levels, teach a mandatory class on vacuum pumps.  I submit for your review a syllabus outline for this class:

Vacuum Pumps 101

  1. Introduction to vacuum pump types: How to tell a rotary vane from a diaphragm pump
  2. When to use a vapor trap: Always
  3. Oil changes: Coors Lite = good, Guinness = bad
  4. Handling acid vapors: How to destroy a pump
  5. Quiz: What is that sound?
  6. Gas ballast use: Why is my pump oil in two phases?
  7. Lab practical: Why are there leftover screws?

So maybe it’s seminar series or a 2-credit class.  Upon completion, students are given a license to use rotary vane pumps.  The lab practical will be graded pass/fail, with failing students relegated to using old rotary evaporator diaphragm pumps.


1 thought on “Vacuum Pumps 101

  1. In grad school 6 years ago, we had a physical chemistry lab dedicated to vacuum pumps. It was mostly self-directed following a manual–disassembly of a pump, measuring a diffusion pump vacuum with a ionization gauge, changing the oil on a pump, and troubleshooting a pump (it had a leaky seal. then we had to put the leaky seal back for the next student.)

    “Lab practical: Why are there leftover screws?”

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