Pump dry gas seal is a non-contact mechanical seal, the use of "gas obstruction" instead of the traditional "liquid obstruction" principle, that is, with pressure sealing gas instead of pressure sealing liquid to ensure that the process medium to achieve "zero leakage" or "zero spill ". Dry gas seal auxiliary system has the advantages of simple structure, convenient operation and maintenance, long service life, low energy consumption, safety and environmental protection. Dry gas seal is mainly used to transport medium toxic, harmful, flammable, explosive and other high-risk media, and does not allow medium leakage conditions.