![]() | COMMERCIAL ENGINE STANDARD PRACTICES MANUAL | Dated: 04/01/2015 |
SPM 70-32-11 WHITE LIGHT INSPECTION | ||
TASK 70-32-11-220-011 |
1 . | General. |
A. | This method of inspection is to be used on parts that have many sheared openings, such as a combustion liner, because it is difficult to tell the difference between shear marks and cracks under fluorescent penetrant-inspection; also use on parts that will retain fluorescent-penetrant oil after cleaning. |
B. | Operational cracking of parts having sheared openings is caused by thermal fatigue. This type of crack is easily seen using white light inspection method. The white light inspection is also used to inspect parts for defects that are visible to the naked eye or with 5X to 10X magnification. |
2 . | Equipment. |
Subtask 70-32-11-220-111 |
A. | The following equipment is required and may be obtained as shown: |
(1) | A 150-watt standard spotlight or 40-watt high intensity spotlight or alternative to acquire necessary illumination as noted (Commercial). |
NOTE: |
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(2) | Magnification equipment 5X to 10X (Commercial). |
3 . | Materials. |
Subtask 70-32-11-220-112 |
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4 . | Procedure. |
Subtask 70-32-11-220-113 |
CAUTION: |
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A. | Clean parts per TASK 70-21-02-110-002, Cleaning Method No. 2 - Vapor Degreasing, (except for titanium parts), or TASK 70-21-03-160-001, Cleaning Method No. 3 - Steam Cleaning, or TASK 70-21-09-110-007, Cleaning Method No. 9 - Light-Duty Alkaline Cleaning of Titanium Alloys, or TASK 70-21-22-110-042, Cleaning Method No. 22 - Light Duty Aqueous Cleaning - Method No. 1, or TASK 70-21-22-110-050, Cleaning Method No. 22 - Light Duty Aqueous Cleaning - Method No. 2, or by a cleaning method specified in the process document for the part to be inspected. |
B. | Inspect the part for cracks under a bright white light (150-watt standard spotlight or equivalent). Hold light within 4 feet (1.2 meters) of the surface being inspected. At minimum, 100 ft-candles (1000 lux) must be achieved at the inspection table top. |
C. | Examine each area where cracks are suspected (using 5- to 10-power magnification) to verify that there is a defect and to determine its course and length. |
D. | Mark each unacceptable defect to indicate its entire length as viewed using the 5- to 10- power magnification, and circle each defect to indicate its location using a marker as specified in Subtask 70-32-11-220-112, Materials. |