After centrifugal compressor control system replacement (2014) Customer claimed surge phenomena (operating instability) before the expected surge line (verified in 2011), dangerous condition for the machine safety. During Troubleshooting activities the compressor operating point showed an anomalous behavior related to the measured flow.
A flowmeter inspection by boroscope was suggested to verify its interior condition and an internal sealing damaged wasfound. The problem was solved installing the pressure transmitter in a different position.