NACE NO 8-1998 Industrial Blast Cleaning (Item No 21088 SSPC-SP 14).pdf

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1、 Item No. 21088 Joint Surface Preparation Standard NACE No. 8/SSPC-SP 14 Industrial 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. It is i

2、ntended 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 standard. Not

3、hing 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 infringement of

4、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 of thi

5、s 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 preclude

6、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 standard

7、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 health, sa

8、fety, 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 review, and

9、 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 publication. Rea

10、ffirmed 2006-09-13 Approved 1998-10-26 ISBN 1-57590-077-7 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 Street, Sixth Floor Pittsburgh

11、, PA 15222 (telephone +1 412/281-2331) Printed by NACE InternationalNACE No. 8/SSPC-SP 14 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 a protective coating or linin

12、g 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 industrial blast cleaning. White metal blast cleaning, near-white metal blast cl

13、eaning, commercial blast cleaning, and brush-off blast cleaning are addressed in separate standards. Industrial blast cleaning provides a greater degree of cleaning than brush-off blast cleaning (NACE No. 4/SSPC-SP 71) but less than commercial blast cleaning (NACE No. 3/SSPC SP-62). Industrial blast

14、 cleaning is used when the objective is to remove most of the coating, mill scale, and rust, while the extra effort required to remove every trace of these is determined to be unwarranted. The difference between an industrial blast cleaning and a brush-off blast cleaning is that the objective of a b

15、rush-off blast cleaning is to allow as much of an existing adherent coating to remain as possible, while the purpose of the industrial blast cleaning is to remove most of the existing coating. A commercial blast cleaned surface is free of mill scale, rust, and coatings, and allows only random staini

16、ng on less than 33 percent of each unit area of surface. The industrial blast cleaned surface allows defined mill scale, coating, and rust to remain on less than 10 percent of each unit area of surface and allows defined stains to remain on all surfaces. This joint standard was originally prepared i

17、n 1998 by the SSPC/NACE Task Group (TG) A on Surface Preparation by Abrasive Blast Cleaning. This joint TG includes members of both the SSPC Surface Preparation Committee and the NACE Unit Committee T-6G on Surface Preparation. It was reaffirmed in 2006 by NACE Specific Technology Group (STG) 04, Pr

18、otective 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 Paragraph 2.2.1.8 of the Agreement Between NACE International and SSPC: The Society for Protective Coatings. The

19、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 state something considered optional. _ NACE No. 8/SSPC-SP 14 ii NACE International _ Joint Surface Preparation St

20、andard NACE No. 8/SSPC-SP 14 Industrial Blast Cleaning Contents 1. General 1 2. Definitions 1 3. Associated Documents 1 4. Procedures Before Cleaning 1 5. Blast Cleaning Methods and Operation . 2 6. Blast Cleaning Abrasives . 2 7. Procedures Following Blast Cleaning and Immediately Prior to Coating

21、2 8. Inspection . 3 9. Safety and Environmental Requirements 3 10. Comments (Nonmandatory) 3 References 4 Appendix A: Explanatory Notes (Nonmandatory). 4 _ NACE No. 8/SSPC-SP 14 NACE International 1 _ Section 1: General 1.1 This joint standard covers the requirements for industrial blast cleaning of

22、 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 verify the end condition. 1.2 The mandatory requirements are described in Sections 1 to 9. Section 10, “Comments,” and Appendi

23、x A,“Explanatory Notes,” are not mandatory requirements of this standard. 1.3 Information about the function of industrial blast cleaning is in Paragraph A1 of Appendix A. 1.4 Information about use of this standard in maintenance coating work is in Paragraph A2 of Appendix A. _ Section 2: Definition

24、s 2.1 Industrial Blast Cleaned Surface: An industrial blast cleaned surface, when viewed without magnification, shall be free of all visible oil, grease, dust, and dirt. Traces of tightly adherent mill scale, rust, and coating residues are permitted to remain on 10 percent of each unit area of the s

25、urface (approximately 5,800 mm29.0 in.2) (i.e., a square 76 mm x 76 mm 3.0 in. x 3.0 in.) if they are evenly distributed. The traces of mill scale, rust, and coating are considered to be tightly adherent if they cannot be lifted with a dull putty knife. Shadows, streaks, and discolorations caused by

26、 stains of rust, stains of mill scale, and stains of previously applied coating may be present on the remainder of the surface. 2.1.1 The shape, configuration, and design of structures can lead to areas of limited accessibility for blast cleaning. Examples include crevices around rivets or fasteners

27、, and behind or between tightly configured back-to-back angles. Because of the limited accessibility, these areas are exempt from the 10 percent restrictions established in Paragraph 2.1. However, all surfaces in limited-access areas shall be subjected to the abrasive blast, and on completion, oldco

28、ating, rust, and mill scale are permitted to remain provided they are well-adherent as determined using a dull putty knife. 2.1.2 Acceptable variations in appearance that do not affect surface cleanliness as defined in Paragraph 2.1 include variations caused by type of steel, original surface condit

29、ion, thickness of the steel, weld metal, mill or fabrication marks, heat treating, heat-affected zones, blasting abrasives, and differences because of blasting technique. 2.1.3 SSPC-VIS 13, ISO(1)8501-14(Condition B Sa 2), or other reference photographs or comparators may be used to supplement the w

30、ritten definition. Condition B Sa 2 of ISO 8501-1 does not depict the influence that previously applied coating may have on the appearance of the cleaned surface. It is based on cleaning of a previously uncoated steel surface covered with rust and flaking mill scale. Additional information on refere

31、nce 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 effect on the date of invitation to bid shall govern unless otherwise specified. 3.2 If there is a conflict bet

32、ween 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 standard include: _ (1) International Organization for Standardization (ISO), 1 rue de Varembe, Case postale

33、 56, CH-1211 Geneva 20, Switzerland. NACE No. 8/SSPC-SP 14 2 NACE International Document Title SSPC-AB 15Mineral and Slag Abrasives SSPC-AB 26Cleanliness of Recycled Ferrous Metallic Abrasives SSPC-AB 37Ferrous Metallic Abrasives SSPC-SP 18Solvent Cleaning SSPC-VIS 1 Guide and Reference Photographs

34、for Steel Surfaces Prepared by Dry Abrasive Blast Cleaning ISO 8501-1 Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness _ Section 4: Procedures Before Cleaning 4.1 Before blast cleaning, visible deposits of oil, grease, or othe

35、r 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 slag should be removed from the surface to the extent required by the procurement documents (project s

36、pecification). 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 condition of the steel prior to blast cleaning should be determined before the blasting commences. Additi

37、onal information on reference photographs and comparators is in Paragraph A3 of Appendix A. _ Section 5: Blast Cleaning Methods and Operation 5.1 Clean, dry compressed air shall be used for nozzle blasting. Moisture separators, oil separators, traps, or other equipment may be necessary to achieve th

38、is requirement. 5.2 Any of the following methods of surface preparation may be used to achieve an industrial blast cleaned surface: 5.2.1 Dry abrasive blasting using compressed air, blast nozzles, and abrasive. 5.2.2 Dry abrasive blasting using a closed-cycle, recirculating abrasive system with comp

39、ressed air, blast nozzle, and abrasive, with or without vacuum for dust and abrasive recovery. 5.2.3 Dry abrasive blasting using a closed-cycle, recirculating abrasive system with centrifugal wheels and abrasive. 5.3 Other methods of surface preparation (such as wet abrasive blast cleaning) may be u

40、sed to achieve an industrial blast cleaned surface by mutual agreement between those responsible for establishing the requirements and those responsible for performing the work. Information on the use of inhibitors to prevent the formation of rust immediately after wet abrasive blast cleaning is in

41、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, 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 prof

42、ile roughness), and whether the abrasive will be recycled. 6.2 The cleanliness and size of recycled abrasives shall be maintained to ensure compliance 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 fo

43、und 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 allowable embedment shall be included in the procurement documents (project specification) covering the work, NACE No. 8/SSPC-SP 14 NACE International 3 be

44、cause abrasive embedment and abrasives containing contaminants may not be acceptable for some service requirements. Additional information on abrasive selection is in Paragraph A6 of Appendix A. 6.5 When a coating is specified, the cleaned surface shall be roughened to a degree suitable for the spec

45、ified 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: Procedures Following Blast Cleaning and Immediately Prior to Coating 7.1 Visible deposits of oil, grease, or other

46、 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 work. 7.2 Dust and loose residues shall be removed from prepared surfaces by brushing; blowing off with clean, d

47、ry 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 metals 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 Mois