6. Vacuum pump oils

There are many different types of oil pump in industrial use.

All use or can use oil, not only for its lubricating action, but also for functional purposes.

Ejectors, which may use air, water or steam as the motive medium, also work with oil vapour in certain applications.

Liquid ring pumps don't just work with a water ring, although this is their most widespread use. Applications involving other fluids, such as oil, are becoming increasingly common.

Finally, the whole family of oscillating piston, oil-sealed vane and oil-bath multi-vane pumps operate with liquid oil introduced into the compression chamber itself.

The functions required of this oil are multiple. First, it must fulfill its usual role as a lubricant. Secondly, it plays a part in heat transfer within...