1、 Standard Practice SSPC Surface Preparation Standard NACE WAB-2/SSPC-SP 10 (WAB) Near-White Metal Wet Abrasive Blast Cleaning This NACE International/SSPC: The Society for Protective Coatings joint standard for qualifying and certifying industrial coating and lining application specialists represent
2、s a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude anyone, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not
3、in conformance with this standard practice. Nothing contained in this NACE/SSPC standard is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by letters patent, or as indemnifying or protectin
4、g anyone against liability for infringement of letters patent. This standard represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedures or materials not discussed herein. Neither is this standard intended to apply in all cases relating to the
5、 subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE and SSPC assume no responsibility for the interpretation or use of this standard by other parties, and accept responsibility for only those official NACE or SSPC interpretations issued by NAC
6、E or SSPC in accordance with their governing procedures and policies, which preclude the issuance of interpretations by individual volunteers. Users of this NACE/SSPC standard are responsible for reviewing appropriate health, safety, and regulatory documents and for determining their applicability i
7、n relation to this standard prior to its use. This NACE/SSPC standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE/SSPC
8、 standard also are responsible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regulatory requirements prior to the use of this standard. CAUT
9、IONARY NOTICE: NACE/SSPC joint surface preparation standards are subject to periodic review, and may be revised or withdrawn at any time in accordance with NACE/SSPC technical committee procedures. NACE and SSPC require that action be taken to reaffirm, revise, or withdraw this standard no later tha
10、n five years from the date of initial publication and subsequently from the date of each reaffirmation or revision. The user is cautioned to obtain the latest edition. Purchasers of NACE/SSPC standards may receive current information on all standards and other NACE/SSPC joint publications by contact
11、ing the organizations at the addresses below: ISBN 1-57590-322-9 Approved Date: 2015-03-14 NACE International 15835 Park Ten Place Houston, TX 77084-5145 +1 281-228-6200 2015, NACE International SSPC: The Society for Protective Coatings 800 Trumbull Drive Pittsburgh, PA 15205 +1 412-281-2331 2015, S
12、SPC: The Society for Protective Coatings NACE SP0615 WAB Item No. 21197 NACE WAB-2/SSPC-SP 10 (WAB) NACE International i _ Foreword This NACE/SSPC joint standard defines the process for preparing a carbon steel surface to the Near-White Metal degree of surface cleanliness using a wet abrasive blast
13、(WAB) method of cleaning. This standard is intended for use by coating or lining specifiers, applicators, inspectors, or others whose responsibility is to define a standard degree of surface cleanliness for carbon steel surfaces to be achieved by wet abrasive blast cleaning. WAB cleaning is a proces
14、s using a mixture of water and abrasive that can produce various levels of surface cleanliness and surface profile (roughness) similar to those obtained with dry abrasive blast (DAB) cleaning. WAB cleaning may be specified when dust suppression is desired, and may also be a means for reducing solubl
15、e salt contamination. The WAB cleanliness level specified should be the same as the corresponding degree of cleaning specified if DAB cleaning were the process being used. The focus of this standard is Near-White Metal WAB cleaning. The five degrees of WAB cleaning are as follows: Near-White Metal W
16、AB cleaning provides a greater degree of cleaning than Commercial WAB cleaning (NACE WAB-3/SSPC-SP 6 WAB) but less than White Metal WAB cleaning (NACE WAB 1/SSPC- SP 5 WAB). Near-White Metal WAB cleaning is used when the objective is to remove all rust and other corrosion products, coating, and mill
17、 scale, but when the extra effort required to remove all stains of these materials is determined to be unwarranted. Near-White Metal WAB cleaning allows staining on no more than 5% of each unit area of surface, while commercial WAB cleaning allows staining on no more than 33% of each unit area of su
18、rface. White Metal WAB cleaning does not permit any staining to remain on the surface. This standard references the three levels of flash rust as defined in the NACE/SSPC joint standards for waterjetting (see Paragraph 3.1 in this standard).5-8 Nonmandatory Appendixes A, B, and C offer additional in
19、formation regarding flash rust. Steel surfaces prepared by WAB cleaning can develop flash rust within minutes after the cleaning is completed. The project specification often contains requirements for the permissible level of flash rust before coating application (Additional information is provided
20、in Appendix A, Paragraph A1 and Appendix C.) Degree of Surface Cleanliness Designation White Metal WAB NACE WAB-1/SSPC-SP 5 (WAB)1 Near-White Metal WAB NACE WAB-2/SSPC-SP 10 (WAB) Commercial WAB NACE WAB-3/SSPC-SP 6 (WAB)2 Industrial WAB NACE WAB-8/SSPC-SP 14 (WAB)3 Brush-Off WAB NACE WAB-4/SSPC-SP
21、7 (WAB)4 ii NACE International This standard was prepared in 2015 by NACE/SSPC Joint Task Group (TG) 350A, “Surface Preparation by Wet Abrasive Blast Cleaning.” TG 350A is administered by NACE Specific Technology Group (STG) 04, “Coatings and Linings, Protective: Surface Preparation”; and SSPC C.2 S
22、urface Preparation Group Committee. This joint standard is issued by NACE/SSPC under the auspices of NACE STG 04 and SSPC C.2. This standard is one of a set of five standards on the degrees of surface cleanliness to be achieved by WAB cleaning. In NACE/SSPC standards, the terms shall, must, should,
23、and may are used in accordance with the definitions of these terms in the NACE/SSPC Joint Publications Style Manual, Paragraph 2.2.1.8. Shall and must are used to state mandatory requirements. The term should is used to state something considered good and is recommended but is not mandatory. The ter
24、m may is used to state something considered optional. _ NACE International iii _ Joint NACE Standard Practice/SSPC Surface Preparation Standard NACE WAB-2/SSPC-SP 10 (WAB) Near-White Metal Wet Abrasive Blast Cleaning Contents 1. General 1 2. Definitions .1 3. Additional Technical Considerations .1 4
25、. Associated Documents .2 5. Procedures Before Wet Abrasive Blast Cleaning .2 6. Wet Abrasive Blast Cleaning Methods .3 7. Wet Abrasive Blast Cleaning Materials 3 8. Procedures Following Wet Abrasive Blast Cleaning and Immediately Before Coating 3 References 5 Appendix A: Explanatory Notes (Nonmanda
26、tory) 6 Appendix B: Procedures and Process Control (Nonmandatory) 10 Appendix C: Methods of Assessing the Degree of Flash Rust (Nonmandatory) 11 TABLE C1: Assessment of Degree of Flash RushTape Pull Test 11 _ NACE WAB-2/SSPC-SP 10 (WAB) NACE International 1 _ Section 1: General 1.1 A WAB-cleaned sur
27、face is one prepared by combining water and abrasive in a blast cleaning operation by one of several methods, including 1) injection of water into the abrasive stream either internally or externally as the abrasive stream exits the blast nozzle; 2) injection of abrasive into pressurized water; or 3)
28、 use of an abrasive slurry under pressure to achieve the specified WAB degree of cleanliness. 1.2 This standard defines the Near-White Metal Wet Abrasive Blast Cleaning (NACE WAB-2/SSPC-SP 10 WAB) degree of visible surface cleanliness of uncoated or coated steel surfaces achieved by the use of wet a
29、brasive blast cleaning. The requirements include the end condition of the surface as determined by visual inspection, and materials and procedures used to achieve and verify the end condition. 1.3 This standard is limited to requirements for visible surface contaminants. Additional information on no
30、nvisible contamination is provided in Paragraph A2 of Appendix A. Additional information on soluble salt testing is provided in SSPC-Guide 15.9 1.4 Information about the function of WAB cleaning is provided in Paragraph A3 of Appendix A. 1.5 Information about use of this standard in maintenance coat
31、ing work is provided in Paragraph A4 of Appendix A. _ Section 2: Definition 2.1 Near-White Metal WAB Surface: A near-white metal WAB-cleaned surface, when viewed without magnification, shall be free of all visible oil, grease, dust, dirt, mill scale, rust, coating, corrosion products, and other fore
32、ign matter. Random staining shall be limited to no more than 5% of each unit area of the surface (approximately 5,800 mm2 9.0 in2; i.e., a square 76 mm x 76 mm 3.0 in x 3.0 in), and may consist of light shadows, slight streaks, or minor discolorations caused by stains of rust, stains of mill scale,
33、or stains of previously applied coating. _ Section 3: Additional Technical Considerations 3.1 Flash Rust: Flash rust is an oxidation product that forms as a wetted carbon steel substrate dries. Flash rust is an additional consideration when a carbon steel substrate is subjected to WAB cleaning. Addi
34、tional information is provided in Section 8. Degrees of flash rust may be qualitatively described as follows: 3.1.1 No flash rust: A carbon steel surface that, when viewed without magnification, exhibits no visible flash rust. 3.1.2 Light (L) flash rusted surface: A carbon steel surface that, when v
35、iewed without magnification, exhibits small quantities of a rust layer through which the carbon steel substrate may be observed. The rust or discoloration may be evenly distributed or present in patches, but it is tightly adherent and not easily removed by lightly wiping with a cloth. (Table C1 in A
36、ppendix C provides flash rust evaluation criteria if the tape pull test is specified for assessing the degree of flash rust.) 3.1.3 Moderate (M) flash rusted surface: A carbon steel surface that, when viewed without magnification, exhibits a layer of rust that obscures the original carbon steel surf
37、ace. The rust layer may be evenly distributed or present in patches, but it is reasonably well adherent and leaves light marks on a cloth that is lightly wiped over the surface. (Table C1 Appendix C provides flash rust evaluation criteria if the tape pull test is specified for assessing the degree o
38、f flash rust.) 3.1.4 Heavy (H) flash rusted surface: A carbon steel surface that, when viewed without magnification, exhibits a layer of heavy rust that hides the original carbon steel surface completely. The rust may be evenly distributed or present in patches, but it is loosely adherent, easily co
39、mes off, and leaves significant marks on a cloth that is lightly wiped over the surface. (Table C1 Appendix C, provides flash rust evaluation criteria if the tape pull test is specified for assessing the degree of flash rust.) 3.1.5 Additional information is provided in Paragraphs A3, A5, A6, and A7
40、 of Appendix A. Additional information on methods of assessing the degree of flash rust is provided in Appendix C. NACE WAB-2/SSPC-SP 10 (WAB) 2 NACE International 3.1.6 NOTE: When performing the wipe test mentioned in Paragraphs 3.1.2, 3.1.3, and 3.1.4 and described in Paragraph C2 of Appendix C, t
41、he angular profile that results from surface preparation using WAB cleaning can pull lint from a cloth. The pressure-sensitive tape pull test, which is an alternate technique for determining the level of flash rust that does not involve cloth and will not deposit lint on a WAB-cleaned surface, is de
42、scribed in Appendix C. 3.2 Appearance Variations 3.2.1 Acceptable variations in appearance that do not affect the degree of surface cleanliness defined in Paragraph 2.1 include variations caused by composition of the metallic substrate, original surface condition, thickness of the metal, weld metal,
43、 mill or fabrication marks, heat treating, heat-affected zones, and differences resulting from the abrasive blast pattern. 3.2.2 The visual appearance of WAB-cleaned surfaces is not necessarily the same as the visual appearance of DAB cleaned surfaces. Visual guides or reference photographs, such as
44、 SSPC-VIS 1, prepared as a guide to the amount of material or staining allowed to remain on the cleaned surface for the various degrees of DAB cleaning, do not depict the appearance of the flash rust that often occurs with WAB cleaning.10 Visual guides or reference photographs prepared for DAB clean
45、ed surfaces must not be used as inspection or judgment criteria for WAB-cleaned surfaces. Direct correlation to existing dry abrasive blasting standards and visual comparators may be inaccurate, inappropriate, or both. 3.3 NACE VIS-9/SSPC-VIS 511 or other visual guide or comparator may be specified
46、to supplement the written definition. In any dispute, the written standard shall take precedence over the visual guide or comparator. Additional information is provided in Paragraph A6 of Appendix A and in Appendix B. _ Section 4: Associated Documents 4.1 Documents cited in the mandatory sections of
47、 this standard include: Document Title SSPC-AB 112 Mineral and Slag Abrasives SSPC-SP 113 Solvent Cleaning ASTM D 428515 ASTM(1) D428514 Method for Indicating the Presence of Oil or Water in Compressed Air 4.2 The latest issue, revision, or amendment of the documents listed in Paragraph 4.1 in effect on the date of invitation to bid shall govern unless otherwise specified. 4.3 If there is a conflict between the requirements of any of the documents listed in Paragraph 4.1 and this standard, the requirements of this standard shall prevail. _
