Dry Gas Seal (DGS) Separation Seal Failure
MetadataShow full item record
This case study presents the failures experienced on separation seals installed on several compressors. The failures resulted in oil migration to the dry gas seals. Segmented contact-type carbon ring bushing separation seals were installed in multiple compressors in an ethylene plant. It was observed that the secondary drain was collecting oil after a few months of operation in spite of maintaining the optimum N2 supply pressure for the separation seals. Subsequent inspection of the dry gas seals confirmed oil ingress into the secondary seals which led to contact between seal faces. Excessive wear on the separation seal carbon bushings was also observed. Failure analysis was performed and root cause identified. Various solutions were studied and some preliminary design changes were implemented in the seals. However these changes did not improve the oil migration issue. Further site evaluation combined with OEM support resulted in implementation of two design changes which have effectively mitigated the oil migration. This case study will present the problems encountered, root causes analyzed, solutions implemented, learnings and the results after 4 years of operation.
Woon Lip, Teo; Mathew, Ajay; Mane, Raj; Ogata, Takayuki (2018). Dry Gas Seal (DGS) Separation Seal Failure. Turbomachinery Laboratory, Texas A&M Engineering Experiment Station. Available electronically from