Dry Gas Seal Condition Monitoring With Embedded Acoustic Emissions Sensors

Dry gas seals (DGS) are commonly used in turbomachinery applications when handling gases. These applications include centrifugal compressors, expanders, and turbines. Historically, DGS have been monitored via leakage and pressure measurements taken outside of the compressor. In recent years, researchers and DGS manufacturers have developed monitoring systems with sensors embedded in the seal. These systems allow seal designers, equipment manufacturers, and machinery operators to monitor the condition of the seal during operation via direct seal measurements as opposed to the traditional downstream or upstream measurements. Acoustic Emission (AE) sensors measure high frequency elastic waves. Embedding these sensors into a DGS offers an exciting possibility to measure elastic waves propagating through the DGS metalwork. This paper will show how measuring acoustic vibrations on a test rig and on field installations provides the opportunity to monitor the health of a DGS.