Preliminary Requirements

Procedure

1. SUBTASK 72-41-11-180-006 Control of Equipment and Materials

   1. Refer to the SPM TASK 70-23-00-230-501.

2. SUBTASK 72-41-11-230-127 Do a Focus FPI of the HP Compressor Stage 8 Disk Inner Cavity Front Face

   1. Refer to Figure.

   2. Clean the HP compressor stage 3 to 8 drum before you start the inspection. Refer to TASK 72-41-11-110-001 (Special Procedure). Use CoMat 01-025 NITRIC ACID HNO3, TECHNICAL GRADE.

   3. Visually examine the stage 7/8 disk inner cavity at inspection location 10, for surface contamination that can mask the cracks.

      1. Use a hand held or fixture mounted white light source and inspection mirror. If contamination is found, refer to TASK 72-41-11-200-001 (Inspection-001).

   4. Penetrant application and processing.

      1. NOTE

         Penetrant processing must be done in accordance with the SPM TASK 70-23-00-230-501 and SPM TASK 70-23-04-230-501. Use CoMat 06-022 FLUORESCENT PENETRANT (POST-EMULSIFIED ULTRA HIGH SENSITIVITY), CoMat 06-045 EMULSIFIER - FLUORESCENT PENETRANT, HYDROPHILIC and CoMat 06-030 NON AQUEOUS DEVELOPER to find the crack). This TASK gives additional instructions necessary because of part's geometry.

         Penetrant must be first applied to the stage 7/8 disk inner cavity before you apply it to the external surfaces of the drum.

         The part must be dry and cool 120 deg F (49 deg C maximum) before you apply the penetrant to prevent damage to the penetrant liquid.

         Apply CoMat 06-022 FLUORESCENT PENETRANT (POST-EMULSIFIED ULTRA HIGH SENSITIVITY) to location 10 (refer to Figure).

         1. Make sure that the stage 7/8 inner cavity surfaces are fully covered with the penetrant, with the use of a mirror and UV light source, specially on the area outboard from the bolt holes. The penetrant contact time must not be less than 20 minutes and not more than 60 minutes.

      2. Initial Cleaning.

         1. Do the cleaning initially until all the pooled penetrant and the unwanted surface on the inner cavity is removed. If necessary, use a standard spray gun nozzle to clean the inner surfaces.

      3. Emulsification.

         1. The maximum total CoMat 06-045 EMULSIFIER - FLUORESCENT PENETRANT, HYDROPHILIC contact time is 90 seconds.

         2. If the part is held horizontally during the process, put half of the HP compressor stage 3 to 8 drum initially into the emulsifier and let the cavities to fill with emulsifier. Rotate the drum a number of turns before you put the drum fully into the emulsifier.

         3. If the part is held vertically during the process, tap the part lightly on each side when you put the part fully into the emulsifier to make sure that the surface is covered and the air pockets are removed from the inner cavity.

      4. Stop bath.

         1. To prevent contamination of the stop bath, remove the unwanted emulsifier from the internal cavity with a suction tube before you put the part fully into the stop bath. You must complete this procedure in the permitted emulsification time.

         2. Put the part fully into water stop bath to stop the emulsification process.

      5. Final cleaning with water.

         1. Make sure that the HP compressor 7/8 inner cavity surfaces are fully cleaned. If necessary, move and rotate the drum to clean. Use a standard spray gun to clean the inner surfaces.

      6. Remove the pooled water.

         1. Remove the pooled water in the inner cavities of the part with the use of suction device and air blast with maximum of 25 psi (0.17 kPa). If necessary, move and rotate the part to remove the water.

      7. Oven dry. Refer to SPM TASK 70-23-04-230-501.

         1. Dry the part in an air re-circulating oven.

         2. If necessary, apply more air blast with the maximum of 25 psi (0.17 kPa) to remove the remaining pooled water in the inner cavity. If necessary, move and rotate the drum to remove water from the inner cavity. Make sure that the part is made dry in the permitted drying time.

         3. Before you apply the developer, make sure that the HP compressor 7/8 inner cavity surfaces are fully dry with the use of a mirror.

      8. Apply developer.

         1. Apply CoMat 06-032 DRY DEVELOPER to the HP compressor 7/8 inner cavity surfaces. Use a standard spray gun nozzle to apply the developer to the inner surfaces.

         2. Make sure that inner cavities are fully covered with the developer, with the use of a white light source and an inspection mirror.

         3. Let the developer dry for a minimum of 10 minutes before you continue with the inspection.

   5. Examine the HP compressor 7/8 inner cavity at inspection location 10 for cracks.

      1. NOTE

         A second operator will be necessary to help in examining the component.

         Refer to Figure.

      2. Engage the part onto the inspection devices IAE 2R19883 Rotary table inspection device and IAE 2R19884 Adapter or IAE approved alternative, such that the stage 7/8 inner bores get easy access to the illumination equipment. Make sure that the part can be rotated easily related to the viewing and illumination equipment.

      3. Inspection area location 10 must be directly illuminated with UV light held in the fixture IAE 2R19883 Rotary table inspection device or IAE approved alternative, as reflecting UV off the inspection mirror decreases its intensity. The UV light guide must also be used in its operational range to make sure sufficient UV intensity.

      4. Visually examine the HP compressor stage 7/8 inner cavity at inspection location 10 for cracks with the use of a mirror and UV light source.

      5. If a crack indication is found, apply penetrant wipe off procedure. Refer to the SPM TASK 70-23-04-230-501, SUBTASK 70-23-04-230-004

         1. If there is a repeat crack indication, reject the drum.

            NOTE

            Make sure that a rejected drum is disposed in line with the individual overhaul shop procedure.

         2. If there is no repeat crack indication, examine the part for crack indications again after 10 minutes of application of the CoMat 06-030 NON AQUEOUS DEVELOPER.

            1. If crack indications are found, reject the drum.

               NOTE

               Make sure that a rejected drum is disposed in line with the individual overhaul shop procedure.

      6. If there is no crack indication, apply CoMat 06-030 NON AQUEOUS DEVELOPER with aerosol to the HP compressor stage 7/8 inner cavity inspection location 10 and examine immediately.

         1. If there is a repeat crack indication, reject the drum.

            NOTE

            Make sure that a rejected drum is disposed in line with the individual overhaul shop procedure.

         2. If there is no crack indication, examine the part for cracks again after 10 minutes of application of the CoMat 06-030 NON AQUEOUS DEVELOPER.

            1. If crack indications are found, reject the drum.

               NOTE

               Make sure that a rejected drum is disposed in line with the individual overhaul shop procedure.

      7. Final cleaning.

         1. Clean location 10 in accordance with SPM TASK 70-11-26-300-503.

Figure: HP Compressor Stage 7/8 Inner Cavity Profile - Focus Inspection Location

HP Compressor Stage 7/8 Inner Cavity Profile - Focus Inspection Location



Figure: HP Compressor Stage 3 to 8 Drum Installation on Inspection Tooling

HP Compressor Stage 3 to 8 Drum Installation on Inspection Tooling