Abstract: This paper introduces the problems in the operation of floating ring seal of recycle gas compressor in the linear low density polyethylene unit at SINOPEC Guangzhou Company, and analyzes the reasons for the frequent failures of floating ring seal from the aspects of structure, failure phenomenon and sealing principle. In view of the successful application of dry gas seal technology in centrifugal compressors, the measures for replacing the floating ring seal of compressor rotors with dry gas seal were determined. The rotor shaft seal has been continuously and stably operated for two overhaul cycles after the modification, and the operation results show that the dry gas seal of rotors has good effect

Key words: Leakage, Floating ring seal, Dry gas seal