ASTM E165-02

Designation: E 165 – 02 Standard Test Method for Liquid Penetrant Examination1 This standard is issued under the fixed designation E 165; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This test method2 covers procedures for penetrant ex- amination of materials. They are nondestructive testing meth- ods for detecting discontinuities that are open to the surface such as cracks, seams, laps, cold shuts, laminations, through leaks, or lack of fusion and are applicable to in-process, final, and maintenance examination. They can be effectively used in the examination of nonporous, metallic materials, both ferrous and nonferrous, and of nonmetallic materials such as glazed or fully densified ceramics, certain nonporous plastics, and glass. 1.2 This test method also provides a reference: 1.2.1 By which a liquid penetrant examination process recommended or required by individual organizations can be reviewed to ascertain its applicability and completeness. 1.2.2 For use in the preparation of process specifications dealing with the liquid penetrant examination of materials and parts. Agreement by the user and the supplier regarding specific techniques is strongly recommended. 1.2.3 For use in the organization of the facilities and personnel concerned with the liquid penetrant examination. 1.3 This test method does not indicate or suggest criteria for evaluation of the indications obtained. It should be pointed out, however, that after indications have been produced, they must be interpreted or classified and then evaluated. For this purpose there must be a separate code or specification or a specific agreement to define the type, size, location, and direction of indications considered acceptable, and those considered unac- ceptable. 1.4 The values stated in inch-pound units are to be regarded as the standard. SI units are provided for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: D 129 Test Method for Sulfur in Petroleum Products (Gen- eral Bomb Method)3 D 516 Test Method for Sulfate Ion in Water4 D 808 Test Method for Chlorine in New and Used Petro- leum Products (Bomb Method)3 D 1193 Specification for Reagent Water4 D 1552 Test Method for Sulfur in Petroleum Products (High-Temperature Method)3 D 4327 Test Method for Anions in Water by Chemically Suppressed Ion Chromatography4 E 433 Reference Photographs for Liquid Penetrant Inspec- tion5 E 543 Practice for Evaluating Agencies that Perform Non- destructive Testing5 E 1208 Test Method for Fluorescent Liquid Penetrant Ex- amination Using the Lipophilic Post-Emulsification Pro- cess5 E 1209 Test Method for Fluorescent Liquid Penetrant Ex- amination Using the Water-Washable Process5 E 1210 Test Method for Fluorescent Liquid Penetrant Ex- amination Using the Hydrophilic Post-Emulsification Pro- cess5 E 1219 Test Method for Fluorescent Liquid Penetrant Ex- amination Using the Solvent-Removable Process5 E 1220 Test Method for Visible Penetrant Examination Using the Solvent-Removable Process5 E 1316 Terminology for Nondestructive Examinations5 E 1418 Test Method for Visible Penetrant Examination Using the Water-Washable Process5 2.2 ASNT Document: 6 Recommended Practice SNT-TC-1A for Nondestructive Testing Personnel Qualification and Certification ANSI/ASNT CP-189 Standard for Qualification and Certi- fication of Nondestructive Testing Personnel 1 This test method is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.03 on Liquid Penetrant and Magnetic Particle Methods. Current edition approved February 10, 2002. Published April 2002. Originally published as E 165 – 60 T. Last previous edition E 165 – 95. 2 For ASME Boiler and Pressure Vessel Code applications see related Recom- mended Test Method SE-165 in the Code. 3 Annual Book of ASTM Standards, Vol 05.01. 4 Annual Book of ASTM Standards, Vol 11.01. 5 Annual Book of ASTM Standards, Vol 03.03. 6 Available from the American Society for Nondestructive Testing, 1711 Arlin- gate Lane, Columbus, OH 43228-0518. 1 Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. 2.3 Military Standard: MIL-STD-410 Nondestructive Testing Personnel Qualifica- tion and Certification7 2.4 APHA Standard: 429 Method for the Examination of Water and Wastewater8 2.5 AIA Standard: NAS-410 Certification and Qualification of Nondestructive Test Personnel6 3. Terminology 3.1 The definitions relating to liquid penetrant examination, which appear in Terminology E 1316, shall apply to the terms used in this standard. 4. Summary of Test Method 4.1 A liquid penetrant which may be a visible or a fluores- cent material is applied evenly over the surface being examined and allowed to enter open discontinuities. After a suitable dwell time, the excess surface penetrant is removed. A devel- oper is applied to draw the entrapped penetrant out of the discontinuity and stain the developer. The test surface is then examined to determine the presence or absence of indications. NOTE 1—The developer may be omitted by agreement between pur- chaser and supplier. NOTE 2—Caution: Fluorescent penetrant examination shall not follow a visible penetrant examination unless the procedure has been qualified in accordance with 10.2, because visible dyes may cause deterioration or quenching of fluorescent dyes. 4.2 Processing parameters, such as surface precleaning, penetration time and excess penetrant removal methods, are determined by the specific materials used, the nature of the part under examination, (that is, size, shape, surface condition, alloy) and type of discontinuities expected. 5. Significance and Use 5.1 Liquid penetrant examination methods indicate the pres- ence, location and, to a limited extent, the nature and magni- tude of the detected discontinuities. Each of the various methods has been designed for specific uses such as critical service items, volume of parts, portability or localized areas of examination. The method selected will depend accordingly on the service requirements. 6. Classification of Penetrations and Methods 6.1 Liquid penetrant examination methods and types are classified as shown in Table 1. 6.2 Fluorescent penetrant examination utilizes penetrants that fluoresce brilliantly when excited by black light (see 8.9.1.2). The sensitivity of fluorescent penetrants depends on their ability to be retained in the various size discontinuities during processing, then to bleed out into the developer coating and produce indications that will fluoresce. Fluorescent indi- cations are many times brighter than their surroundings when viewed under black light illumination. 6.3 Visible penetrant examination uses a penetrant that can be seen in visible light. The penetrant is usually red, so that the indications produce a definite contrast with the white back- ground of the developer. The visible penetrant process does not require the use of black light. However, visible penetrant indications must be viewed under adequate white light (see 8.9.2.1). 7. Types of Materials 7.1 Liquid penetrant examination materials (see Notes 3 and 4) consist of fluorescent and visible penetrants, emulsifiers (oil-base and water-base), solvent removers and developers. A family of liquid penetrant examination materials consists of the applicable penetrant and emulsifier or remover, as recom- mended by the manufacturer. Intermixing of penetrants and emulsifiers from various manufacturers is not recommended. NOTE 3—Refer to 9.1 for special requirements for sulfur, halogen and alkali metal content. NOTE 4—Caution: While approved penetrant materials will not ad- versely affect common metallic materials, some plastics or rubbers may be swollen or stained by certain penetrants. 7.2 Penetrants: 7.2.1 Post-Emulsifiable Penetrants are designed to be in- soluble in water and cannot be removed with water rinsing alone. They are designed to be selectively removed from the surface using a separate emulsifier. The emulsifier, properly applied and given a proper emulsification time, combines with the excess surface penetrant to form a water-washable mixture, which can be rinsed from the surface, leaving the surface free of fluorescent background. Proper emulsification time must be experimentally established and maintained to ensure that over-emulsification does not occur, resulting in loss of indica- tions. 7.2.2 Water-Washable Penetrants are designed to be di- rectly water-washable from the surface of the test part, after a suitable penetrant dwell time. Because the emulsifier is “built- in” to the water-washable penetrant, it is extremely important to exercise proper process control in removal of excess surface penetrant to ensure against overwashing. Water-washable pen- etrants can be washed out of discontinuities if the rinsing step is too long or too vigorous. Some penetrants are less resistant to overwashing than others. 7.2.3 Solvent-Removable Penetrants are designed so that excess surface penetrant can be removed by wiping until most of the penetrant has been removed. The remaining traces 7 Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. 8 Available from American Public Health Association, Publication Office, 1015 Fifteenth Street, NW, Washington, DC 20005. TABLE 1 Classification of Penetrant Examination Types and Methods Type I—Fluorescent Penetrant Examination Method A—Water-washable (see Test Method E 1209) Method B—Post-emulsifiable, lipophilic (see Test Method E 1208) Method C—Solvent removable (see Test Method E 1219) Method D—Post-emulsifiable, hydrophilic (see Test Method E 1210) Type II—Visible Penetrant Examination Method A—Water-washable (see Test Method E 1418) Method C—Solvent removable (see Test Method E 1220) E 165 – 02 2 should be removed with the solvent remover (see 8.6.4.1). To minimize removal of penetrant from discontinuities, care should be taken to avoid the use of excess solvent. Flushing the surface with solvent to remove the excess penetrant is prohib- ited. 7.3 Emulsifiers: 7.3.1 Lipophilic Emulsifiers are oil-miscible liquids used to emulsify the excess oily penetrant on the surface of the part, rendering it water-washable. The rate of diffusion establishes the emulsification time. They are either slow- or fast-acting, depending on their viscosity and chemical composition, and also the surface roughness of the area being examined (see 8.6.2). 7.3.2 Hydrophilic Emulsifiers are water-miscible liquids used to emulsify the excess oily fluorescent penetrant on the surface of the part, rendering it water-washable (see 8.6.3). These water-base emulsifiers (detergent-type removers) are supplied as concentrates to be diluted with water and used as a dip or spray. The concentration, use and maintenance shall be in accordance with manufacturer’s recommendations. 7.3.2.1 Hydrophilic emulsifiers function by displacing the excess penetrant film from the surface of the part through detergent action. The force of the water spray or air/mechanical agitation in an open dip tank provides the scrubbing action while the detergent displaces the film of penetrant from the part surface. The emulsification time will vary, depending on its concentration, which can be monitored by the use of a suitable refractometer. 7.4 Solvent Removers function by dissolving the penetrant, making it possible to wipe the surface clean and free of excess penetrant as described in 8.6.1.2 and 8.6.4. 7.5 Developers—Development of penetrant indications is the process of bringing the penetrant out of open discontinui- ties through blotting action of the applied developer, thus increasing the visibility of the indications. 7.5.1 Dry Powder Developers are used as supplied (that is, free-flowing, non-caking powder) in accordance with 8.8.2. Care should be taken not to contaminate the developer with fluorescent penetrant, as the penetrant specks can appear as indications. 7.5.2 Aqueous Developers are normally supplied as dry powder particles to be either suspended or dissolved (soluble) in water. The concentration, use and maintenance shall be in accordance with manufacturer’s recommendations (see 8.8.3). NOTE 5—Caution: Aqueous developers may cause stripping of indica- tions if not properly applied and controlled. The procedure should be qualified in accordance with 10.2. 7.5.3 Nonaqueous Wet Developers are supplied as suspen- sions of developer particles in a nonaqueous solvent carrier ready for use as supplied. Nonaqueous, wet developers form a coating on the surface of the part when dried, which serves as the developing medium (see 8.8.4). NOTE 6—Caution: This type of developer is intended for application by spray only. 7.5.4 Liquid Film Developers are solutions or colloidal suspensions of resins/polymer in a suitable carrier. These developers will form a transparent or translucent coating on the surface of the part. Certain types of film developer may be stripped from the part and retained for record purposes (see 8.8.5). 8. Procedure 8.1 The following processing guidelines apply to both fluorescent and visible penetrant examination methods (see Figs. 1-3). 8.2 Temperature Limits—The temperature of the penetrant materials and the surface of the part to be processed should be between 40° and 125°F (4° and 52°C). Where it is not practical to comply with these temperature limitations, qualify the procedure as described in 10.2 at the temperature of intended use and as agreed to by the contracting parties. 8.3 Surface Conditioning Prior to Penetrant Examination— Satisfactory results usually may be obtained on surfaces in the as-welded, as-rolled, as-cast, or as-forged conditions (or for ceramics in the densified conditions). Sensitive penetrants are generally less easily rinsed away and are therefore less suitable for rough surfaces. When only loose surface residuals are present, these may be removed by wiping with clean lint-free cloths. However, precleaning of metals to remove processing residuals such as oil, graphite, scale, insulating materials, coatings, and so forth, should be done using cleaning solvents, vapor degreasing or chemical removing processes. Surface conditioning by grinding, machining, polishing or etching shall follow shot, sand, grit or vapor blasting to remove the peened skin and when penetrant entrapment in surface irregularities might mask the indications of unacceptable discontinuities or otherwise interfere with the effectiveness of the examination. For metals, unless otherwise specified, etching shall be per- formed when evidence exists that previous cleaning, surface treatments or service usage have produced a surface condition that degrades the effectiveness of penetrant examination. (See A1.1.1.8 for precautions.) NOTE 7—When agreed between purchaser and supplier, grit blasting without subsequent etching may be an acceptable cleaning method. NOTE 8—Caution: Sand or shot blasting may possibly close disconti- nuities and extreme care should be used with grinding and machining operations to avoid masking discontinuities. NOTE 9—For structural or electronic ceramics, surface preparation by grinding, sand blasting and etching for penetrant examination is not recommended because of the potential for damage. 8.4 Removal of Surface Contaminants: 8.4.1 Precleaning—The success of any penetrant examina- tion procedure is greatly dependent upon the surrounding surface and discontinuity being free of any contaminant (solid or liquid) that might interfere with the penetrant process. All parts or areas of parts to be examined must be clean and dry before the penetrant is applied. If only a section of a part, such as a weld, including the heat affected zone is to be examined, all contaminants shall be removed from the area being exam- ined as defined by the contracting parties. “Clean” is intended to mean that the surface must be free of rust, scale, welding flux, weld spatter, grease, paint, oily films, dirt, and so forth, that might interfere with the penetrant process. All of these contaminants can prevent the penetrant from entering discon- tinuities (see Annex on Cleaning of Parts and Materials). E 165 – 02 3 NOTE 10—Caution: Residues from cleaning processes such as strong alkalies, pickling solutions and chromates, in particular, may adversely react with the penetrant and reduce its sensitivity and performance. 8.4.2 Drying after Cleaning—It is essential that the surface of parts be thoroughly dry after cleaning, since any liquid residue will hinder the entrance of the penetrant. Drying may be accomplished by warming the parts in drying ovens, with infrared lamps, forced hot air, or exposure to ambient tempera- ture. 8.5 Penetrant Application—After the part has been cleaned, dried, and is within the specified temperature range, the penetrant is applied to the surface to be examined so that the entire part or area under examination is completely covered with penetrant. 8.5.1 Modes of Application—There are various modes of effective application of penetrant such as dipping, brushing, flooding, or spraying. 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. Both conventional and electrostatic spray guns are effective means of applying liquid penetrants to the part surfaces. Electrostatic spray application can eliminate excess liquid build-up of penetrant on the part, minimize overspray, and minimize the amount of penetrant entering hollow-cored passages which might serve as penetrant reservoirs, causing severe bleedout problems during Incoming Parts PRECLEAN Alkaline Steam Vapor De-grease Solvent Wash Acid Etch (See 8.4.1) Mechanical Paint Stripper Ultrasonic Detergent DRY (See 8.4.2) Dry PENETRANT APPLICATION (See 8.5) Apply Water- Washable Penetrant FINAL RINSE (See 8.6.1) Water Wash Spray Dip DRY DEVELOP (See 8.7) (See 8.8) Dry Developer(Aqueous) DEVELOP DRY (See 8.8) (See 8.7) Developer, Dry, Nonaqueous or Liquid Film Dry EXAMINE Fluorescent (See 8.9.1) Examine Visible (See 8.9.2) Water Rinse Detergent MechanicalWash POST CLEAN (See 8.10 and An- nex A1 on Post Cleaning.) Dry Vapor De- grease Solvent Soak Ultrasonic Clean Outgoing Parts FIG. 1 General Procedure Flowsheet for Penetrant Examination Using the Water-Washable Process (Test Method E 1209 for Fluorescent and Test Method E 1220 for Visible Light) E 165 – 02 4 FIG. 2 General Procedure Flowsheet for Post-emulsifiable Method E 165 – 02 5 examination. Aerosol sprays are conveniently portable and suitable for local application. NOTE 11—Caution: Not all penetrant materials are suitable for elec- trostatic spray applications, so tests should be conducted prior to use. NOTE 12—Warning: With spray applications, it is important that there be proper ventilation. This is generally accomplished through the use of a properly designed spray booth and exhaust system. 8.5.2 Penetrant Dwell Time—After application, allow ex- cess penetrant to drain from the part (care should be taken to prevent pools of penetrant from forming on the part), while allowing for proper penetrant dwell time (