REVISION : 0 / EXAMINATION PROCEDURE / PAGE : 1 OF 8
PROCEDURE FOR
LIQUID PENETRANT EXAMINATION
as per
AWS D 1.1
0
REV. NO. / DATE / APPROVED BY :
LEVEL III / APPROVED BY : / APPROVED BY :
.
DOC. NO.: / LIQUID PENETRANT / ISSUED :REVISION : 0 / EXAMINATION PROCEDURE / PAGE : 1OF 8
PROCEDURE FOR
LIQUID PENETRANT EXAMINATION
as per
AWS D 1.1
0
REV. NO. / DATE / APPROVED BY :
LEVEL III / APPROVED BY : / APPROVED BY :
PROCEDURE FOR LIQUID PENETRANT EXAMINATION
(AWS D 1.1)
TABLE OF CONTENTS
DescriptionPage No.
1.0Scope4 of 8
2.0General Requirements4 of 8
a. Personnel Qualifications
b. Surface Preparation
3.0Technique and Material5 of 8
a. Definitions
b. Penetrant
c. Developer
4.0Examination5 of 8
a. Pre-cleaning
b. Drying
c. Temperature
d. Penetrant Application
e. Excess Penetrant Removal
f. Drying
g. Development
h. Interpretation
5.0 Evaluation and Acceptance Standard8 of 8
a. Acceptance Standards
b. Examination After Repairs
6.0Records8 of 8
1.0SCOPE
This procedure describes the method to be used for Liquid Penetrant Examination in accordance with the requirements of:- AWS D.1.1
AWS D 1.1
When the applicable code section or specification demands that project oriented details are defined, such as identification of materials, product shapes and product sizes, these shall be listed in a separate procedure which shall be used in conjunction with this procedure.
2.0 GENERAL REQUIREMENTS
aPersonnel Qualifications
NDE Personnel shall be qualified and certified in accordance with the companies “Written Practice” for the qualification and certification of personnel, which conforms to the Recommended Practice SNT-TC-1A, 1984 Edition.
bSurface Preparation
In general, satisfactory results may be obtained when the surface of the part is in the as-welded, as-rolled, as cast, as-forged condition. Surface preparation by grinding, machining or other methods may be necessary where surface irregularities could mask indications of unacceptable discontinuities.
Caution : Blasting with shot or dull sand may close discontinuities at the
surface and should not be used.
3.0 TECHNIQUE AND MATERIALS
ADefinitions
The term penetrant as used in this procedure is intended to include all penetrant, solvents or cleaning agents, developers, etc. used in the examination process.
WARNING
We point out that the use of aerosol containers in closed areas is dangerous and therefore it is forbidden.
bPenetrant
A color contrast solvent removable penetrant technique shall be used. The penetrant is usually red in color so that the indications produce a definite contrast with the white background of the developer.
cDeveloper
A wet developer shall be used, it shall be applied by spraying.
4.0 EXAMINATION
aPre-cleaning
Prior to all liquid penetrant examinations, the surface to be examined and all adjacent areas within at least 1 inch (25mm) shall be dry and free of all dirt, grease, lint, scale, welding flux, weld spatter, oil and 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 solution and paint removers. Degreasing and ultrasonic cleaning method may also be used.
bDrying
After cleaning, drying of the surfaces to be examined shall be accomplished by normal evaporation or with forced hot air, as appropriate. A minimum period of time shall be established to ensure that the cleaning solution has evaporated prior to application of the penetrant.
cTemperature
As a standard technique, the temperature of the penetrant and the surface of the part to be processed shall not be below 16 C nor above 52 C throughout the examination period. Local heating or cooling is permitted provided the part temperature remain in the range of 16 C to 52 C during the examination.
dPenetrant Application
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 up-stream side near the air inlet to preclude contamination of the penetrant by oil, water, dirt or sediment that may have collected in the lines.
eExcess Penetrant Removal
Any penetrant remaining on the surface shall be removed, Care shall be taken to minimize removal of penetrant from discontinuities after a minimum well time of 10 minutes for casting and welds and 15 minutes for extruded and forged materials.
Excess solvent removable penetrant shall be removed by wiping with a cloth or absorbent paper, repeating the operation until most traces of penetrant have been removed. The remaining traces shall be removed by lightly wiping the surface with cloth or absorbent paper moistened with solvent.
To minimize removal of penetrant from discontinuities, care shall be taken to avoid the use of excess solvent. Flushing the surface with solvent following the application of the penetrant and prior to developing is prohibited.
fDrying
For the solvent removable technique, the surface may be dried by normal evaporation, blotting, wiping or forced air.
gDeveloping
The developer shall be applied as soon as possible after the excess penetrant has been removed and the surface has dried. Solvent suspension developer shall be applied by spraying, except where safety, health or restricted access preclude it. Under such condition, solvent suspended developer may be applied by brushing.
hInterpretation
The true size and type of discontinuities are difficult to evaluate if the penetrant diffuses excessively into the developer. Consequently, the surface shall be closely observed during the application of the developer to monitor the behavior of the indications which tend to bleed-out profusely.
Final interpretation shall be made after allowing the penetrant to bleed-out for 7 to 30 minutes. If bleed-outdoes not alter the examination result, longer period are permitted.
If the surface to be examined is large enough to preclude complete examination within the prescribed time, the surface shall be examined in increments.
Ambient light shall be minimum 1000 lux.
5.0EVALUATION AND ACCEPTANCE STANDARD
All indications shall be evaluated in terms of the acceptance standards. Discontinuities at the surface will be indicated by bleed-out of penetrant, however, localized surface irregularities due to machining marks or other surface conditions may produce false indications.
Broad areas of pigmentation which could mask indications of discontinuities are unacceptable and such areas shall be cleaned are re-examined.
aAcceptance Standard
Acceptance criteria of a component shall be referred to the applicable Section of AWS D 1.1.
bExamination After Repairs
All repaired areas shall be re-examined according to this procedure.
6.0 RECORDS
For each liquid penetrant examination the following information should be identified on a standard report form.
a. Client / Contractor
b. Object/ Parts
c. Materials, shapes and sizes to be examined plus the extent of examination
d. Method and type of penetrant materials
e. Surface condition and temperature
f. Procedure number
g. Results
h. Name and level personnel
i. Date of examination