Lab vacuum pumps: Selection and protection

Vacuum pumps are real workhorses in many labs, supporting applications as varied as filtration, evaporation, freeze-drying and mass spectrometry. Yet scientists and technicians are often unfamiliar with how to select the right pump and protect it to ensure long, reliable service. To get the best performance, we need a pump that operates in the range required for our application. A pump designed to evaporate liquids is not useful if what we want to do is filter and collect them. Once the vacuum level that will optimize operations is identified, you need to figure out how big a pump is needed, that is, the pumping speed or free air displacement required by your application. The next tip is to never buy an oil-sealed pump if an oil-free (dry) pump will suffice. For some applications, only an oil-sealed pump will provide the vacuum depth you need. But for most lab applications—such as drying, evaporation, aspiration, filtration, degassing, concentration and solid-phase extraction (SPE)—an oil-free diaphragm pump will provide not only vacuum in the appropriate range, but will also be cleaner, quieter, more chemical resistant and require less maintenance. It is always best to speak with a manufacturer’s rep about your needs before ordering a pump.