GE MS6001B, Maintenance Instructions Manual

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Scheduled Turbine Maintenance Inspection and Maintenance — GEK 107048
STM-13
Areas of Inspection
In the hands of a qualified technician, the borescope allows rapid inspection of the following areas with
minimum outage time, manpower, and loss of production.
1. Turbine section
2. Axial flow compressor
3. Combustion system
Note: The combustion system may be examined by removing the fuel nozzles
to gain access. The interior surfaces of the cap and liner and primary
fuel nozzles may be inspected through the instrumentation ports on the
combustion outer casings.
Table 4-1 lists the inspection criteria for these areas of inspection. Table 4-2 lists the access holes location,
casing holes thread size, dimension from forward face of compressor discharge case and number of holes
in each location.
Figure 4-1 locates the borescope access holes for the various locations.
Equipment Required
A rigid borescope with high-quality rigid lens system plus a flexible fiber bundle to introduce light
at the borescope tip from an external light projector is the basic equipment needed for visual inspec-
tion of the turbine and compressor. The combustion system including the transition pieces can only
be inspected using a flexible fiberoptic borescope. See Figures 4-2 and 4-3.
A qualified technician using this equipment can make visual observation and record the observed
details.
Additional auxiliary equipment desirable to supplement the basic equipment includes a borescope
support mount or fixture, camera attachments, camera, and a television camera with recording capa-
bility and playback monitor. See Figures 4-4 and 4-5.
Borescope Inspection Programming
A planned borescope inspection program results in opening a turbine unit only when necessary to re-
pair or replace parts. It should be recognized that inspection intervals are based on average unit operat-
ing modes. Adjustment of these intervals may be made based on experience and the individual unit
mode of operation and the fuels used.
The borescope inspection program should include:
1. Baseline inspection and recording of conditions, both written and photographically, at the time
of startup.
2. Periodic inspection and recording of the results.