Advanced Turbine Support Inc has identified the first R-1 platform crack on a 7FA compressor using the phased array ultrasonic inspection. The crack was found using a specialised inspection method developed by ATS that allows us to inspect the R-1 platforms through the inlet with no unit disassembly. The crack was verified by the utilities NDE group after the unit was disassembled. Our inspection meets the requirements of TIL 1638.
Normally this inspection can only be performed after major unit disassembly. Our technique enables us to perform this inspection now during a single day outage. This has the ability to prevent catastrophic compressor failures and save significant maintenance costs by avoiding unit disassembly.
This inspection was developed in response to several R-1 liberations that caused major damage to the affected units. Advanced Turbine Support has also been instrumental in providing phased array ultrasonics on both the standard and P-Cut R-0 blades. These inspections have resulted in finding 66 R-0 blades with cracks in the dovetail regions. Only six of these cracks were on P-Cut blades.