Eng 2100 Project 2

Technicians are responsible to comply with this procedure and to complete all required records/reports. At any time while performing work with this procedure, should it become evident that the requirements herein cannot be met, the technician is to immediately contact their supervisor or lead technician, as applicable, for resolution. Technicians are to ensure that the item being inspected receives 100% inspection of all accessible areas within the inspection zone. Accessible areas are defined as those where all test parameters can be applied in accordance with the NOE procedure and the results properly viewed for interpretation/evaluation. In addition, inspection zone areas that are found to be inaccessible are to be recorded in the report.

Unless otherwise specified by contract, PO or customer specifications, personnel performing Liquid Penetrant examinations shall be qualified and certified in accordance with reference 2.7, which complies with SNT-TC-1A. – Personnel performing evaluations and/or reporting results in accordance with this procedure shall be certified Level II as a minimum. The liquid penetrant examination materials should be used in well ventilated areas because they are highly volatile and flammable. The penetrant should not be heated above 125 °F, or exposed to open flames or hot surfaces.

Care shall be taken to avoid overheating of pressurized cans. If they must be heated to reach the required examination temperatures, heating shall be accomplished by using a hot water bath. Should there be a question or a clarification needed to any safety requirement, the supervisor, lead technician or facility representative, as applicable, is to be contacted for resolution before beginning or resuming work.

Alloys

When examining austenitic or duplex stainless steels, titanium, or nickel base alloys, the total sulfur and total halogen (chlorine and fluorine) content shall not exceed 1% of the residue by weight. Certification of contaminant content for all liquid penetrant materials shall be obtained from the manufacturer and maintained. This certification shall include manufacturer's batch numbers and test results as required by the referencing Code Section.

Light meters, both visible and ultraviolet, shall be calibrated at least once a year or whenever the meter is repaired. – If meters have not been used for one year or more, calibration shall be done before being used.

Intermixing of penetrant materials from different family groups or different manufactures is not permitted.

Application

With color-contrast penetrants, only a wet developer shall be used. With fluorescent penetrants, a wet or a dry developer may be used.

The temperature of the penetrant and the surface of the material or weld under examination shall not be below 40°F or above 125 °F throughout the examination period. Local heating or cooling is permitted provided the temperatures remain in the range of 40° °F during the examination.

Prior to liquid penetrant examination, the surface to be examined and all adjacent areas within at least one (1) inch shall be dry and free of any dirt, grease, lint, scale, welding flux, weld spatter, oil, or other extraneous matter that could obscure surface openings or otherwise interfere with the examination. Typical cleaning agents, which may be used, are detergents, organic solvents, descaling solutions, and paint removers. Degreasing and ultrasonic cleaning methods may also be used.

Drying of the surface to be examined shall be accomplished by normal evaporation allowing at least one minute but not more than 4 hours for normal evaporation before application of the liquid penetrant.

The penetrant may be applied by dipping, brushing, or spraying. If the penetrant is applied by spraying using compressed air type apparatus, filters shall be placed on the upstream side near the air inlet to preclude contamination of the penetrant by oil, water or dirt sediment that may have collected in the lines. 2 Small parts are quite often placed in suitable baskets and dipped into a tank of penetrant. On larger parts and those with complex geometries, penetrant can be applied effectively by brushing or spraying.

The penetrant application shall completely cover the surface of the area under examination and at least the area if the entire component is not examined. Dwell times shall not exceed the manufacturer's recommended range unless demonstrated and documented on a similar part under inspection. Unless otherwise specified, the presence of cracks should be assumed, and additional dwell time may be required when parts of unfamiliar types are first examined.

After the specified dwell time has elapsed, any penetrant remaining on the surface shall be removed, taking care to minimize removal of penetrant from possible discontinuities.

The excess penetrant, in so far as possible, shall be removed by wiping with a lint-free cloth or absorbent paper, repeating the operation until most traces of penetrant have been removed. The remaining traces shall be removed by wiping the surface lightly with a dry, lint-free cloth or absorbent paper moistened with solvent. Be careful of overuse of solvent. Flushing the surface with solvent, following the application of the penetrant and prior to developing is not permitted.

The precise drying time is dependent upon dimensions and geometry, drying procedure, and humidity, but the minimum drying time shall be 10 minutes. Maximum drying time shall be 30 minutes for warm air driers and 2 hours for blotting. The surface may be dried by normal evaporation, or forced air. The drying time shall be a minimum of 1 minute and a maximum of 30 minutes. The developer shall be applied as soon as possible after the penetrant removal, but the time interval shall not be less than the minimum nor more than the maximum drying times specified.

Developer

Either an aqueous or a non-aqueous wet developer may be used. Prior to applying the wet developer to the surface, the developer shall be thoroughly agitated to ensure adequate dispersion of the suspended particles. Only a wet developer shall be used with visible (color- contrast) penetrants.

The developing time required to draw penetrant from discontinuities into the dried developer on the surface shall be a minimum of 10 minutes and a maximum of 60 minutes. Interpretation of examination results for acceptance purposes must be made within this time period. If bleedout does not alter the examination results, longer periods are permitted. If the surface to be examined is so large as to preclude complete examination within the prescribed time, only portions of the surface shall be examined at any one time. The surface being examined should be observed during the developing period in order to detect the nature of certain indications which might tend to bleed out profusely. Precautions should be taken to prevent any object from touching the dry developer film because it is very brittle, loosely held and easily damaged. The true size and type of discontinuities are difficult to evaluate if the penetrant diffuses excessively in the developer. Consequently it is good practice to observe the surface during the application of the developer to detect the nature of any indications, which tend to bleed out profusely.

Post-Cleaning

Final cleaning shall be accomplished with an approved manufacturer's cleaner or a cleaner approved by the referencing Code Section or customer specification.