Sealing High-Speed Shafts in Turbomachinery

Rotating liquid pump shafts that are originally sealed with soft packings mostly use contacting face seals, also known as mechanical seals. Typical rotational speeds are roughly between 1,000 and 3,600 revolutions per minute (rpm). In turbomachinery—such as compressors and expanders—the rotational speeds are higher and mechanical seals would not immediately appear to be an option, due to greater rubbing speeds along with a lack of liquid cooling and lubrication. Nevertheless, from the late 1970s when they were first marketed, noncontacting mechanical seals, known as dry gas seals in cartridge form, have been used in most gas turbomachinery.

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