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TASK 72-32-01-300-809
1 . Corrosion Repair of the Aft Flange Bolthole.
A.This procedure gives instructions to repair the high pressure compressor stator forward case assembly (HPC case) by reaming the aft flange boltholes to remove corrosion pitting. Refer to Figure 901.
NOTE:
Hole No. 94 is not applicable to this repair procedure because it has different geometry and dimensional tolerance than the other holes.
B.The following maximum repairable limits apply to this repair:
NOTE:
The information below gives maximum repairable limits for the applicable Inspection sections. The paragraphs are numbered the same as the manual Inspection sections.
(4)Visual Inspection.
(e)Do an inspection of the circumferential flanges. Refer to Figure 802 and as follows:
5Corrosion pitting in the aft circumferential flange boltholes:
Maximum repairable limit:
Any amount, 0.008 inch (0.20 mm) in depth after reaming the bolthole to a diameter of 0.417 inch (10.59 mm).
C.The subsequent table gives a list of the part numbers that are applicable to this repair. All part numbers are applicable to all paragraphs unless specified differently.
 
Part Number(s)
 
2302M67G07  
2302M67G11  
2644M01G01  
2514M80G01  
D.Proprietary/Complex Process Statement.
(1)None.
2 . Tools, Equipment, and Materials.
NOTE:
Repair sources can use equivalent alternatives for tools, equipment, and consumable materials, however, the repair source must demonstrate and document equivalency.
A.Tools and Equipment.
(1)Special Tools. None.
(2)Standard Tools and Equipment.
 
Description
Manufacturer
 
Reamers (0.407 inch (10.34 mm), 0.412 inch (10.46 mm), 0.417 inch (10.59 mm) diameter)
Local Purchase
(3)Locally Manufactured Tools.
 
Description
Figure
 
Machining Fixture
905
B.Consumable Materials.
 
Code No.
Description
 
C03-038
Paint, Sermetel (Sermetel W paint) (paint)
 
C05-003
Marking Pens (marking pen)
 
C10-012
Tape, Masking, High Temperature (masking tape)
 
C10-155
Shims, Metal (shims)
C.Referenced Procedures.
 
ATA No.
Description
 
70-00-03
Machining Data
 
70-21-00
Chemical Cleaning
 
70-21-03
Cleaning Method No. 3 - Steam Cleaning
 
70-21-06
Cleaning Method No. 6 - Heavy-Duty Alkaline Cleaner (without Inhibited Phosphoric Acid)
 
70-21-14
Cleaning Method No. 14 - Manually-Assisted Detergent Cleaning
 
70-23-00
Stripping Procedures
 
70-23-23
Removal of Coatings by High Pressure Water Stripping
 
70-24-00
Etching Procedures for Fluorescent-Penetrant Inspection
 
70-24-01
Swab Etching Procedure
 
70-31-02
Acceptability Limits for Fluorescent-Penetrant Inspection
 
70-32-00
Indirect Inspection Methods
 
70-32-03
Spot-Fluorescent-Penetrant Inspection
 
70-42-00
Blending and Removal of High Metal Procedures
 
70-43-05
Inorganic Aluminum Protective Coating
 
72-32-01
Cleaning 001
 
72-32-01
Inspection 001
D.Expendable Parts. None.
E.SPD Information.
(1)Spares Supplied. None.
(2)Protected Spares. None.
(3)Locally Manufactured Spares. None.
F.Special Solutions. None.
G.Test Specimens. None.
3 . Dimensional Information.
Subtask 72-32-01-220-124
A.Refer to Figure 901 for specified dimensions and locations.
NOTE:
The dimensional data identified within this procedure was designed using inches as the base unit of measurement for dimensional values. The conversion to millimeters is rounded to one less decimal digit than inches. For minimum dimensions, converted values are rounded up. For maximum dimensions, converted values are rounded down. To avoid conversion errors, do not re-convert from millimeters to inches.
NOTE:
Reference dimensions do not require inspection.
4 . Setup Information.
Subtask 72-32-01-320-015
A.Alternative Procedure Available. Set-up the HPC case for machining. Refer to Figure 902 and as follows:
(1)If necessary, make the machining fixture. Refer to Figure 905.
(2)Install the machining fixture on the machining table and do as follows:
(a)Make surface FB flat to 0.001 inch (0.02 mm) or less and as follows:
1If necessary, put C10-155  shims between the machining fixture and the machining table.
(b)Make diameter FA concentric to the machining table axis to 0.001 inch (0.02 mm) or less.
(c)Use clamps or 0.625 inch (15.88 mm) bolts to attach the machining fixture to the machining table.
(3)If necessary, assemble the upper and lower HPC case halves to make the HPC case assembly. Refer to TASK 72-32-01-200-801 (72-32-01, INSPECTION 001).
(4)Put the assembled HPC case on the machining fixture and do as follows:
(a)Put the forward flange of the HPC case (surface B) on the machining fixture as follows:
1Align the forward flange boltholes with the boltholes on the machining fixture.
2Use 28 0.375-16 bolts with 28 washers to attach the HPC case assembly to the machining fixture.
Subtask 72-32-01-320-016
A.A.Alternative Procedure. Set-up the HPC case for machining. Refer to Figure 902 and as follows:
(1)If necessary, assemble the upper and lower HPC case halves to make the HPC case assembly. Refer to TASK 72-32-01-200-801 (72-32-01, INSPECTION 001).
(2)If there is no fixture available, install the HPC case assembly with the forward flange (surface B) down on ground blocks. Refer to Figure 901 and as follows:
(a)Make surface C flat to 0.002 inch (0.05 mm) or less and as follows:
1If necessary, put C10-155  shims between the restraining fixture and the machining table.
(b)Make diameter D concentric to the machining table axis to 0.002 inch (0.05 mm) or less.
(c)Attach the forward flange with machine clamps with Teflon spacers to prevent damage to the forward flange.
5 . Procedure.
Subtask 72-32-01-160-012
A.Clean the HPC case. Refer to TASK 72-32-01-100-801 (72-32-01, CLEANING 001), and as follows:
Subtask 72-32-01-110-018
CAUTION:
DO NOT PUT ALL THE HPC CASE INTO THE CLEANING SOLUTION. THIS CAN CAUSE DAMAGE TO THE VSV BUSHINGS AND THE STAGE 1 AND STAGE 2 FLOWPATH ABRADABLES. ONLY PUT THE CIRCUMFERENTIAL AFT FLANGE OF THE HPC CASE INTO THE CLEANING SOLUTION.
(1)Alternative Procedure Available. If the boltholes have C03-038  paint on them, clean the circumferential aft flange of the HPC case. Refer to TASK 70-21-00-110-051 (CHEMICAL CLEANING), TASK 70-21-06-110-004 (CLEANING METHOD NO. 6 - HEAVY-DUTY ALKALINE CLEANER (WITHOUT INHIBITED PHOSPHORIC ACID)), and as follows:
(a)Clean all the aft circumferential flange boltholes with a nylon brush to remove all the unwanted material from the surface and as follows:
1Do not clean the boltholes with a BZ mark on them.
Subtask 72-32-01-100-005
(1).A.Alternative Procedure. If the boltholes have C03-038  paint on them, remove it from the circumferential aft flange of the HPC case. Refer to TASK 70-23-00-100-001 (STRIPPING PROCEDURES), TASK 70-23-23-330-008 (REMOVAL OF COATINGS BY HIGH PRESSURE WATER STRIPPING).
Subtask 72-32-01-220-125
B.Do a visual inspection of the aft flange boltholes of the HPC case as follows:
(1)Do a check of the aft flange boltholes for signs of corrosion and as follows:
(a)If you find signs of corrosion, use a C05-003  marking pen to do a circular mark on the damaged boltholes.
Subtask 72-32-01-320-017
CAUTION:
REMOVE THE MINIMUM QUANTITY OF PARENT MATERIAL NECESSARY. DO NOT MACHINE MORE THAN THE MAXIMUM REPAIRABLE LIMITS. DAMAGE TO THE HPC CASE CAN OCCUR.
C.Machine the marked aft flange boltholes to remove corrosion from the HPC case. Refer to TASK 70-00-03-800-004 (MACHINING DATA), Figure 901, Figure 902, Figure 904, and as follows:
(1)Set-up the HPC case for machining. Refer to Subtask 72-32-01-320-015 (paragraph 4.A.).
(2)For the boltholes that will be machined, make sure that you set-up the HPC case boltholes within 0.001 inch (0.02 mm) or better to the machine spindle.
Subtask 72-32-01-350-083
(3)Use the reamers to remove corrosion from the boltholes as follows:
(a)You cannot repair bolthole No. 94 with this procedure.
(b)Ream the corroded boltholes to 0.402 inch (10.21 mm) in diameter.
Subtask 72-32-01-220-126
(4)Do a visual inspection of the boltholes for remaining corrosion.
Subtask 72-32-01-350-084
(5)If there is remaining corrosion more than the serviceable limits, continue to ream the bolthole to remove a minimum quantity of material and as follows:
(a)Make sure that you do not increase the bolthole diameter more than 0.417 inch (10.59 mm).
(b)For the serviceable limits. Refer to TASK 72-32-01-200-801 (72-32-01, INSPECTION 001).
Subtask 72-32-01-220-127
D.Do an inspection of the HPC case reamed boltholes and do as follows:
(1)Remaining corrosion cannot be more than the serviceable limits specified in TASK 72-32-01-200-801 (72-32-01, INSPECTION 001).
(2)If the remaining corrosion is more than the serviceable limits specified in TASK 72-32-01-200-801 (72-32-01, INSPECTION 001), you cannot repair the case with this procedure.
Subtask 72-32-01-350-085
E.Blend the HPC case. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) and as follows:
(1)If necessary, blend the repaired boltholes to remove unwanted material.
(2)If necessary, break the edges to 0.005-0.015 inch (0.13-0.38 mm).
Subtask 72-32-01-220-128
F.Do a dimensional inspection of each repaired HPC case bolthole. Refer to Figure 902 and as follows:
(1)Make sure that the diameter of the repaired boltholes are not more than 0.417 inch (10.59 mm) and the remaining corrosion depth is not more than the serviceable limits specified in TASK 72-32-01-200-801 (72-32-01, INSPECTION 001).
Subtask 72-32-01-040-001
G.Disassemble the HPC case halves.
Subtask 72-32-01-160-013
H.Clean the HPC case halves. Refer to TASK 72-32-01-100-801 (72-32-01, CLEANING 001).
Subtask 72-32-01-230-009
I.Swab-etch the case flange reamed boltholes of the HPC case. Refer to TASK 70-24-00-110-033 (ETCHING PROCEDURES FOR FLUORESCENT-PENETRANT INSPECTION), TASK 70-24-01-110-034 (SWAB ETCHING PROCEDURE), and as follows:
(1)Use Class C etchant.
Subtask 72-32-01-230-010
J.Do an inspection of the flange reamed boltholes of the HPC case. Refer to TASK 70-32-00-200-002 (INDIRECT INSPECTION METHODS), TASK 70-32-03-230-002 (SPOT-FLUORESCENT-PENETRANT INSPECTION) and as follows:
(1)Use Class D penetrant.
(2)For acceptability limits, refer to TASK 70-31-02-220-003 (ACCEPTABILITY LIMITS FOR FLUORESCENT PENETRANT INSPECTION), and as follows:
(a)Use Class A limits.
Subtask 72-32-01-110-019
K.Clean the HPC case as follows:
(1)Clean the circumferential flange boltholes. Refer to TASK 70-21-00-110-051 (CHEMICAL CLEANING), TASK 70-21-14-110-012 (CLEANING METHOD NO. 14 - MANUALLY-ASSISTED DETERGENT CLEANING), and as follows:
(a)Clean all the boltholes with a nylon brush to remove all the unwanted material from the surface and as follows:
1Do not clean the boltholes with a BZ mark on them.
Subtask 72-32-01-110-020
(2)Clean the HPC case. Refer to TASK 70-21-00-110-051 (CHEMICAL CLEANING), TASK 70-21-03-160-001 (CLEANING METHOD NO. 3 - STEAM CLEANING) and as follows:
(a)Fully flush the aft circumferential flange boltholes with water.
Subtask 72-32-01-350-086
L.Apply C03-038  paint to all aft circumferential flange boltholes of the HPC case. Refer to Figure 904 and as follows:
(1)Do not apply C03-038  paint to the boltholes with a BZ mark on them.
(2)Apply C10-012  masking tape to the areas of the HPC case that you will not paint. Refer to Figure 903 and as follows:
(a)If necessary, use a locally manufactured fixture, tape, plastic caps, rubber plugs, or plastic screws to apply mask to the areas that you will not paint.
(b)Make sure that the edges of the C10-012  masking tape get fully in contact with the HPC case.
Subtask 72-32-01-350-087
(3)Apply C03-038  paint to the boltholes as follows:
(a)Apply a layer of C03-038  paint with a brush or spray gun to the inner surface of the boltholes. Refer to TASK 70-43-05-380-005 (INORGANIC ALUMINUM PROTECTIVE COATING), Figure 904, and as follows:
1Do not apply coating to the boltholes with a BZ mark on them.
2If you will spray the C03-038  paint, it is recommended to use spray paint tips for the inner diameter.
3Apply a first layer of C03-038  paint to 0.0007-0.0015 inch (0.018-0.038 mm) in thickness and let the C03-038  paint dry.
4Apply an optional second layer of C03-038  paint to 0.0014-0.0030 inch (0.036-0.076 mm) total thickness. Refer to Figure 904 and as follows:
aDo not apply a second layer of C03-038  paint to bolthole No. 94.
NOTE:
Additional paint can cause difficulty when fitting the bolt at this location.
(4)Remove the masking tape from the HPC case.
Subtask 72-32-01-220-129
(5)Do a check at the aft flange faces to make sure that there is no C03-038  paint overspray and remove as necessary.
Subtask 72-32-01-370-003
WARNING:
USE THERMAL GLOVES WHEN YOU MOVE OR TOUCH HOT OR COLD PARTS. HOT OR COLD PARTS CAN CAUSE INJURY.
(6)Cure the HPC case at 600 to 750°F (316 to 399°C) for 30 to 40 minutes and then let its temperature decrease to room temperature.
Subtask 72-32-01-220-130
(7)Do a check of the painted boltholes of the HPC case to make sure that the aluminum paint is fully applied on the inner diameter of all the boltholes.
Subtask 72-32-01-160-014
M.Clean the aft circumferential flange boltholes of the HPC case. Refer to TASK 72-32-01-100-801 (72-32-01, CLEANING 001).
Subtask 72-32-01-200-002
N.Do an inspection of the HPC case. Refer to TASK 72-32-01-200-801 (72-32-01, INSPECTION 001).
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Figure 901   High Pressure Compressor Case
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Figure 902   High Pressure Compressor Case - Set-up Information
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Figure 903   High Pressure Compressor Case - Masking
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Figure 904   (Sheet 1 ) High Pressure Compressor Case - Hole BZ and Hole No. 94
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Figure 904   (Sheet 2 ) High Pressure Compressor Case - Hole BZ and Hole No. 94
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Figure 905   (Sheet 1 ) Aft Flange Bolthole - Machining Fixture
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Figure 905   (Sheet 2 ) Aft Flange Bolthole - Machining Fixture
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Figure 905   (Sheet 3 ) Aft Flange Bolthole - Machining Fixture
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Figure 905   (Sheet 4 ) Aft Flange Bolthole - Machining Fixture