NACE NO 2-1994 Joint Surface Preparation Standard Near-White Metal Blast Cleaning (Item No 21066 SSPC-SP 10).pdf

1、 Item No. 21066 Joint Surface Preparation Standard NACE No. 2/SSPC-SP 10 Near-White Metal Blast Cleaning This NACE International (NACE)/The Society for Protective Coatings (SSPC) standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. I

2、t is intended to aid the manufacturer, the consumer, and the general public. 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 addressed in this standar

3、d. 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 protecting anyone against liability for infringeme

4、nt of Letters Patent. This standard represents current technology and should in no way be interpreted as a restriction on the use of better procedures or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness

5、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 interpretations issued by NACE or SSPC in accordance with their governing procedures and policies which pre

6、clude the issuance of interpretations by individual volunteers. Users of this NACE/SSPC standard are responsible for reviewing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE/SSPC sta

7、ndard 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 standard are also responsible for establishing appropriate heal

8、th, 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. CAUTIONARY NOTICE: NACE/SSPC standards are subject to periodic revie

9、w, and may be revised or withdrawn at any time in accordance with technical committee procedures. The user is cautioned to obtain the latest edition. NACE and SSPC require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publicatio

10、n. Reaffirmed 2006-09-13 Reaffirmed 1999-09-07 Approved October 1994 ISBN 1-57590-108-0 2006, SSPC: The Society for Protective Coatings and NACE International NACE International 1440 South Creek Dr. Houston, TX 77084-4906 (telephone +1 281/228-6200) SSPC: The Society for Protective Coatings 40 24th

11、Street, Sixth Floor Pittsburgh, PA 15222 (telephone +1 412/281-2331) Printed by NACE InternationalNACE No. 2/SSPC-SP 10 NACE International i _ Foreword This joint standard covers the use of blast cleaning abrasives to achieve a defined degree of cleaning of steel surfaces prior to the application of

12、 a protective coating or lining system. This standard is intended for use by coating or lining specifiers, applicators, inspectors, or others who may be responsible for defining a standard degree of surface cleanliness. The focus of this standard is near-white metal blast cleaning. White metal blast

13、 cleaning, commercial blast cleaning, industrial blast cleaning, and brush-off blast cleaning are addressed in separate standards. Near-white metal blast cleaning provides a greater degree of cleaning than commercial blast cleaning (NACE No. 3/SSPC-SP 61) but less than white metal blast cleaning (NA

14、CE No. 1/SSPC-SP 52). Near-white metal blast cleaning is used when the objective is to remove all rust, coating, and mill scale, but when the extra effort required to remove all stains of these materials is determined to be unwarranted. Staining shall be limited to no more than 5 percent of each uni

15、t area of surface. Near-white metal blast cleaning allows staining on only 5 percent of each unit area of surface, while commercial blast cleaning allows staining on 33 percent of each unit area of surface. White metal blast cleaning does not permit any staining to remain on the surface. This joint

16、standard was originally prepared in 1994 and reaffirmed in 1999 by the SSPC/NACE Task Group (TG) A on Surface Preparation by Abrasive Blast Cleaning, and NACE Unit Committee T-6G on Surface Preparation. This joint TG includes members of both the SSPC Surface Preparation Committee and the NACE Unit C

17、ommittee T-6G on Surface Preparation. It was reaffirmed in 2006 by NACE Specific Technology Group (STG) 04, Protective Coatings and Linings: Surface Preparation, and the SSPC Surface Preparation Committee. In NACE/SSPC standards, the terms shall, must, should, and may are used in accordance with Par

18、agraph 2.2.1.8 of the Agreement Between NACE International and SSPC: The Society for Protective Coatings. The terms 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 term may is used to sta

19、te something considered optional. _ NACE No. 2/SSPC-SP 10 ii NACE International _ Joint Surface Preparation Standard NACE No. 2/SSPC-SP 10 Near-White Metal Blast Cleaning Contents 1. General 1 2. Definitions 1 3. Associated Documents 1 4. Procedures Before Cleaning 1 5. Blast Cleaning Methods and Op

20、eration . 2 6. Blast Cleaning Abrasives . 2 7. Procedures Following Blast Cleaning and Immediately Prior to Coating 2 8. Inspection . 3 9. Safety and Environmental Requirements 3 10. Comments (Nonmandatory) 3 References 3 Appendix A: Explanatory Notes (Nonmandatory). 4 _ NACE No. 2/SSPC-SP 10 NACE I

21、nternational 1 _ Section 1: General 1.1 This joint standard covers the requirements for near-white metal blast cleaning of uncoated or coated steel surfaces by the use of abrasives. These requirements include the end condition of the surface and materials and procedures necessary to achieve and veri

22、fy the end condition. 1.2 The mandatory requirements are described in Sections 1 to 9. Section 10, “Comments,” and Appendix A,“Explanatory Notes,” are not mandatory requirements of this standard. 1.3 Information about the function of near-white metal blast cleaning is in Paragraph A1 of Appendix A.

23、1.4 Information about use of this standard in maintenance coating work is in Paragraph A2 of Appendix A. _ Section 2: Definitions 2.1 Near-White Metal Blast Cleaned Surface: A near-white metal blast cleaned surface, when viewed without magnification, shall be free of all visible oil, grease, dust, d

24、irt, mill scale, rust, coating, oxides, corrosion products, and other foreign matter. Random staining shall be limited to no more than 5 percent of each unit area of surface (approximately 5,800 mm29.0 in.2 (i.e., a square 76 mm x 76 mm 3.0 in. x 3.0 in.), and may consist of light shadows, slight st

25、reaks, or minor discolorations caused by stains of rust, stains of mill scale, or stains of previously applied coating. 2.1.1 Acceptable variations in appearance that do not affect surface cleanliness as defined in Paragraph2.1 include variations caused by the type of steel, original surface conditi

26、on, thickness of the steel, weld metal, mill or fabrication marks, heat treating, heat-affected zones, blasting abrasives, and differences because of blasting technique. 2.1.2 SSPC-VIS 13may be specified to supplement the written definition. In any dispute, the written definition set forth in this s

27、tandard shall take precedence over reference photographs and comparators. Additional information on reference photographs and comparators is in Paragraph A3 of Appendix A. _ Section 3: Associated Documents 3.1 The latest issue, revision, or amendment of the documents listed in Paragraph 3.3 in effec

28、t on the date of invitation to bid shall govern unless otherwise specified. 3.2 If there is a conflict between the requirements of any of the documents listed in Paragraph 3.3 and this standard, the requirements of this standard shall prevail. 3.3 Documents cited in the mandatory sections of this st

29、andard include: Document Title SSPC-AB 14Mineral and Slag Abrasives SSPC-AB 25Cleanliness of Recycled Ferrous Metallic Abrasives SSPC-AB 36Ferrous Metallic Abrasives SSPC-SP 17Solvent Cleaning SSPC-VIS 1 Guide and Reference Photographs for Steel Surfaces Prepared by Dry Abrasive Blast Cleaning _ Sec

30、tion 4: Procedures Before Cleaning 4.1 Before blast cleaning, visible deposits of oil, grease, or other contaminants shall be removed in accordance with SSPC-SP 1 or other agreed-upon methods. 4.2 Before blast cleaning, surface imperfections such as sharp fins, sharp edges, weld spatter, or burning

31、slag should be removed from the surface to the extent required by the procurement documents (project specification). Additional information on surface imperfections is in Paragraph A4 of Appendix A. 4.3 If reference photographs or comparators are specified to supplement the written standard, the con

32、dition of the steel prior to blast cleaning should be determined before the blasting commences. Additional information on reference NACE No. 2/SSPC-SP 10 2 NACE International photographs and comparators is in Paragraph A3 of Appendix A. _ Section 5: Blast Cleaning Methods and Operation 5.1 Clean, dr

33、y compressed air shall be used for nozzle blasting. Moisture separators, oil separators, traps, or other equipment may be necessary to achieve this requirement. 5.2 Any of the following methods of surface preparation may be used to achieve a near-white metal blast cleaned surface: 5.2.1 Dry abrasive

34、 blasting using compressed air, blast nozzles, and abrasive. 5.2.2 Dry abrasive blasting using a closed-cycle, recirculating abrasive system with compressed air, blast nozzle, and abrasive, with or without vacuum for dust and abrasive recovery. 5.2.3 Dry abrasive blasting using a closed-cycle, recir

35、culating abrasive system with centrifugal wheels and abrasive. 5.3 Other methods of surface preparation (such as wet abrasive blast cleaning) may be used to achieve a near-white metal blast cleaned surface by mutual agreement between those responsible for establishing the requirements and those resp

36、onsible for performing the work. Information on the use of inhibitors to prevent the formation of rust immediately after wet abrasive blast cleaning is in Paragraph A5 of Appendix A. _ Section 6: Blast Cleaning Abrasives 6.1 The selection of abrasive size and type shall be based on the type, grade,

37、and surface condition of the steel to be cleaned, the type of blast cleaning system used, the finished surface to be produced (cleanliness and surface profile roughness), and whether the abrasive will be recycled. 6.2 The cleanliness and size of recycled abrasives shall be maintained to ensure compl

38、iance with this standard. 6.3 The blast cleaning abrasive shall be dry and free of oil, grease, and other contaminants as determined by the test methods found in SSPC-AB 1, SSPC-AB 2, and SSPC-AB 3. 6.4 Any limitations on the use of specific abrasives, the quantity of contaminants, or the degree of

39、allowable embedment shall be included in the procurement documents (project specification) covering the work, because abrasive embedment and abrasives containing contaminants may not be acceptable for some service requirements. Additional information on abrasive selection is in Paragraph A6 of Appen

40、dix A. 6.5 When a coating is specified, the cleaned surface shall be roughened to a degree suitable for the specified coating system. Additional information on surface profile and the film thickness of coating applied over the surface profile is in Paragraphs A7 and A8 of Appendix A. _ Section 7: Pr

41、ocedures Following Blast Cleaning and Immediately Prior to Coating 7.1 Visible deposits of oil, grease, or other contaminants shall be removed according to SSPC-SP 1 or another method agreed upon by those parties responsible for establishing the requirements and those responsible for performing the

42、work. 7.2 Dust and loose residues shall be removed from prepared surfaces by brushing; blowing off with clean, dry air; vacuum cleaning; or other methods agreed upon by those responsible for establishing the requirements and those responsible for performing the work. 7.2.1 The presence of toxic meta

43、ls in the abrasives or coating being removed may place restrictions on the methods of cleaning permitted. The chosen method shall comply with all applicable regulations. 7.2.2 Moisture separators, oil separators, traps, or other equipment may be necessary to achieve clean, dry air. 7.3 After blast c

44、leaning, any remaining surface imperfections (e.g., sharp fins, sharp edges, weld spatter, burning slag, scabs, slivers) shall be removed to the extent required by the procurement documents (project specification). Any damage to the surface profile resulting from the removal of surface imperfections

45、 shall be corrected to meet the requirements of Paragraph 6.5. NACE No. 2/SSPC-SP 10 NACE International 3 Additional information on surface imperfections is in Paragraph A4 of Appendix A. 7.4 Immediately prior to coating application, the entire surface shall comply with the degree of cleaning specif

46、ied in this standard. Any visible rust that forms on the surface of the steel after blast cleaning shall be removed by recleaning the rusted areas before coating. Information on chemical contamination, rust-back (rerusting), and the effect of dew point (surface condensation) is in Paragraphs A9, A10

47、, and A11 of Appendix A. _ Section 8: Inspection 8.1 Work performed and materials supplied under this standard are subject to inspection by a representative of those responsible for establishing the requirements. Materials and work areas shall be accessible to the inspector. The procedures and times of inspection shall be