This paper reviews the current state of dynamic sealing technologies, examining the challenges faced by conventional sealing methods under complex working conditions, such as high temperature, high pressure, and corrosive environments. It also provides a concise overview of the status and developmental trends in sealing inspection technologies. From the perspective of obstruction mechanisms, this study reinterprets the concept of sealing science by redefining the classification of sealing types based on solid-phase medium obstruction, fluid hydrostatic and hydrodynamic obstruction, fluid pumping obstruction, fluid energy dissipation obstruction, and fluid impact obstruction. Comparative analyses of sealing structures across these obstruction mechanisms are presented. The sealing technology based on fluid impact medium obstruction, newly proposed by this paper, represents an innovative sealing approach. It offers distinct advantages such as zero wear, structural simplicity, and high stability, addressing longstanding issues in high-speed, large-clearance non-contact seals, including low leakage suppression efficiency, system complexity, and poor stability. Since its introduction, this novel sealing structure has garnered significant attention and recognition from both the academic and industrial sealing communities. With the potential to revolutionize the field, this groundbreaking sealing design is poised to lead the next wave of technological advancements in sealing science.

This study proposes a new near zero-wear non-contact self-impact seal based on the passive fluid blocking principle and the Tesla valve structure, which is characterised by near zero-wear, a long lifetime, a simple structure and high stability. Research shows that the impact-blocking effect of a three-dimensional leakage channel can realise the stepwise throttling effect of the sealing medium. Furthermore, the pressure, number of seal stages and seal spacing significantly affect leakage. Leakage can be effectively controlled by increasing seal series and reducing seal spacing. The proposed near zero-wear impact seal is more suitable for the gas medium. Compared with the conventional sealing form, the new seal is simplified significantly. Large spacing and fixed design can significantly improve the ability to seal pairs to resist vibration and impact during operation, and the sealing performance is not restricted by the rotation speed. The form of the proposed seal will enable a new non-contact mechanical seal technology and a new structure to be developed, thereby advancing the existing seal field.