Gas/steam jet pumps operate based on the Venturi effect.

Unlike water jet vacuum pumps, gas/steam jet vacuum pumps are not limited by the saturated vapor pressure of the liquid, so they can achieve higher vacuum degrees.

A multi-stage jet vacuum unit composed of several water vapor jet vacuum pumps and intermediate condensers can achieve a vacuum where the absolute pressure is lower than 10 Pascals.

The jet vacuum ejector can be made of stainless steel, Monel alloy, Hastelloy alloy, titanium, bronze and other materials. It can also be made of a variety of non-metals, such as graphite and polytetrafluoroethylene.

The number of stages of the vacuum jet unit depends on the required vacuum degree and economic requirements.