TASK 70-32-03-230-002
1 . General.
A.The spot-fluorescent-penetrant inspection process is intended for inspections at remote locations. It is a localized process, limited to small specific areas for inspection. It is not intended as a substitute for normal inspection. It is convenient to use for inspection of welded or other localized repair areas.
B.If visible color dye penetrant has been used on parts which are to be subsequently inspected with fluorescent penetrants, the contamination by the dye may prevent reliable fluorescent penetrant inspection. Any color dye indications evident by white light visual inspection shall be considered valid indications even if not detectable by ultraviolet light.
C.Titanium alloy parts are subject to stress corrosion cracking when residues of halogen containing compounds remain on a part that is subsequently subjected to elevated temperatures typical of welding, heat-treating, or engine operation. These parts must be thoroughly cleaned with nonhalogen compounds after exposure to any halogen containing compound to prevent the cracking and possible failure of parts.
D.Personnel Requirements.
(1)Personnel performing this inspection must be certified in accordance with National Aerospace Standard (NAS-410), American Society of Non Destructive Testing (ASNT-TC-1A), Air Transport Association Specification No. 105 (ATA 105), or locally approved certification program.
(2)Personnel performing this inspection should receive practical training in the use of this procedure and must demonstrate proficiency in use and control of inspection equipment, inspection of hardware, and evaluation of indications before the authority to accept and reject hardware is delegated.
(3)Any training which may be provided by General Electric for a technique requiring the performance of this inspection method does not imply that the personnel who receive that training have met the requirements for inspector certification in accordance with NAS-410, ASNT-TC-1A, or ATA 105.
E.Equivalent Inspection Materials
(1)The materials specified in this procedure (Class D) can be used anytime an inspection per TASK 70-32-03-230-002, Spot-Fluorescent-Penetrant Inspection, Class A, B, C, or D, is specified in a process document. The classes were used in an older version of this manual.
(2)If TASK 70-32-03-230-002, Spot-Fluorescent-Penetrant Inspection, Class G, is specified, then materials in Subtask 70-32-02-230-015, Class G, of TASK 70-32-02-230-001, Fluorescent-Penetrant Inspection, must be used.
(3)It is acceptable to substitute a penetrant of higher sensitivity within the same classification (for example, substitute a level 3 or 4 penetrant for a level 2) provided that the part exhibits a satisfactory indication to background fluorescence contrast.
(4)It is acceptable to substitute the Class G PEP materials for all inspections specified as TASK 70-32-03-230-002, Spot-Fluorescent-Penetrant Inspection, for reasons of shop standardization. Special care must be used with the Class G materials on rough surfaces to ensure low levels of background fluorescence.
CAUTION:
CLEANING IS CRITICAL TO SUCCESSFUL DETECTION OF SURFACE FLAWS USING THE FPI PROCESS. ONLY USE CLEANING PROCEDURES RECOMMENDED IN THE ENGINE/SHOP MANUAL.
F.Surfaces to be inspected shall be clean, dry, and free of soils, paint, grease, oil, and other coatings, corrosion, scale, etc. that could prevent the penetrant from entering discontinuities. In cases where this process is specified on small parts, or small areas of large parts (other than recent rework area), the following applies as a guideline for coating removal: unless otherwise directed by the part process document, soft coatings such as paints, RTV, anti-gallant lubricants, silver pate, etc. are required to be stripped prior to FPI. Harder coatings such as chrome and nickel plate, anodize, etc. need not be stripped unless directed by the part process document. Parts on which coating is to be replaced because of deterioration (peeling, flaking, cracking, etc.) should not be FPI inspected until after the coating is removed. Coatings normally produce areas of excessive background fluorescence (example: thermal spray) and fine network cracking (example: chrome plating) making these areas uninspectable to the level of sensitivity required on the remainder of the part under inspection. These areas are generally not to be inspected unless the coating is removed. Good practice does, however, make sure these areas are reviewed for large and obvious anomalies. The process document will specify when these coatings must be removed for inspection.
NOTE:
Any obvious indications of cracking above the normal level of background indications in the coated areas should be called out for further evaluation by white light inspection or coating removal and reinspection based on the recommendations of the process document.
2 . Equipment.
Subtask 70-32-03-230-021
G.Inspection booth, darkroom, or black cloth hood (for remote locations) to prevent excessive admission of white light.
NOTE:
Excessive white light may interfere with detection of a rejectable size indication. A test part having a known defect can be used to evaluate effectiveness of white light shielding.
H.Compressed air supply for drying parts. Air supply must have filters to remove oil and moisture which can contaminate parts or inspection materials.
I.Ultraviolet lamp to detect fluorescent indications. The ultraviolet (black) light source used for the detection of fluorescent indications shall have an intensity no less than 1000 microwatts per sq. centimeter when measured at 15 in. (381 mm). The black light should be checked on a weekly basis or before use, whichever is less frequent.
J.White light lamp for visual inspection of parts.
K.Time piece for timing operations.
L.Tools for inspection personnel.
(1)Three-power and 10-power magnifying lenses.
(2)Cotton swabs or small fine hair art brush to apply solvents for evaluating questionable indications.
3 . Materials.
Subtask 70-32-03-230-022
M.Materials. All materials are used at ambient temperature. The materials that follow can be used for this class of inspection:
(1)Class D post-emulsifiable penetrant inspection systems as follows:
Approved products for this inspection process are in Qualified Products List QPL-AMS-2644 (latest revision). QPL specifications are available from ASSIST-Acquisition Streamlining and Standardization Information System. Refer to the List of Suppliers in Step 4 of 70-80-00.
For this class of inspection, only use the approved materials that follow:
Type I - Fluorescent Dye
Method C - Solvent removable, or
Method D - Post-emulsifiable, Hydrophilic
Sensitivity Level 3 - High
NOTE:
Hydrophilic remover concentration is 20 percent maximum unless otherwise noted in the QPL for the dip method, and 5 percent maximum for the spray method.
NOTE:
Non-aqueous wet developers are approved for use in aerosol spray only. You can substitute a developer from one manufacturer for another manufacturer's developer.
CAUTION:
TITANIUM PARTS REQUIRE THE USE OF NON-HALOGENATED SOLVENTS OR MANUFACTURERS' NON-HALOGENATED SOLVENT.
(2)Solvents as follows:
 
Solvents
Consumable Product Ref. No.
 
(1) Isopropyl alcohol (halogen-free)
C04-035  
 
(2) MEK (halogen-free)
C04-001  
 
(3) Acetone (halogen-free)
C04-003  
4 . Procedure.
Subtask 70-32-03-230-023
WARNING:
SOLVENTS AND SOME FPI MATERIALS ARE TOXIC. USE IN A WELL-VENTILATED AREA.
N.This procedure is to be used wherever the shop manual calls out specific classes using either water-washable or post-emulsifiable penetrant systems.
O.Parts must be cleaned of all traces of oil, grease, carbon, rust scale prior to penetrant application.
P.Apply penetrant oil with soft-bristle brush, cotton swab or spray application. Allow a minimum of 30 minutes for penetration.
CAUTION:
INDICATIONS OF DEFECTS CAN BE LOST BY USE OF EXCESSIVE SOLVENT.
Q.Alternative procedure available. Wipe off excess penetrant with a clean cloth using one of the solvent listed in Subtask 70-32-03-230-022, Materials.
NOTE:
This procedure is to be used wherever the Engine/Shop Manual calls out specific classes using either water-washable or post-emulsifiable penetrant systems.
Q.A.Alternative procedure. Remove excess penetrant with a hydrophilic remover, provided it belongs to the same family as the penetrant used. Do not exceed 90 seconds contact time. If remover is applied manually, do not scrub the surface of the part with the applicator. Use applicator only to deliver fluid to the part surface.
R.Apply either dry powder or NAWD as a fine thin coating at ambient temperature to a dry surface. Allow a minimum of 10 minutes for developer to absorb penetrant before inspecting part.
S.Evaluate any indication to the required inspection standards.
CAUTION:
TITANIUM ALLOY AND MARAGE 250 PARTS ARE SUBJECT TO STRESS CORROSION CRACKING WHEN RESIDUES OF HALOGEN-CONTAINING COMPOUNDS REMAIN ON A PART THAT IS SUBSEQUENTLY SUBJECTED TO ELEVATED TEMPERATURES TYPICAL OF WELDING, HEAT-TREATING, OR ENGINE OPERATION. THESE PARTS MAY BE THOROUGHLY CLEANED WITH NONHALOGEN COMPOUNDS AFTER EXPOSURE TO ANY HALOGEN-CONTAINING COMPOUND TO PREVENT THE CRACKING AND POSSIBLE FAILURE OF PARTS.
T.Remove all residues by spraying, wiping, or soaking with approved solvents.