A certain pharmaceutical machinery factory in central China encountered a key technical bottleneck when advancing the process improvement of large-volume infusion equipment — the equipment was required to simultaneously meet complex operating conditions such as ventilation during operation, liquid-passing reaction, and tank body rotation, while insufficient sealing performance became the core issue restricting the upgrade. After conducting systematic research on the equipment structure and the whole-process technology, our team developed a customized multifunctional rotary joint device. With in-depth adaptation to on-site process parameters, this device, relying on breakthroughs in multi-layer sealing technology and the design of fluid dynamic control, not only fully meets the sealing requirements for ventilation, liquid-passing reaction and tank body rotation, but also improves the stability and reliability of equipment operation, thus completely overcoming the sealing technical problem that had long plagued