SSPC PA COM-2004 Commentary on Paint Application《涂料应用的说明》.pdf

1、7-1SSPC-PA COMNovember 1, 2004SSPC: The Society for Protective CoatingsPAINT APPLICATION SPECIFICATIONS AND GUIDESCommentary on Paint Application1. IntroductionThis commentary is for information only and is not part of the standards and guides in this chapter. Its purpose is to present a general des

2、cription of the sections that comprise this chapter: (1) SSPC PA 1, “Shop, Field, and Maintenance Painting of Steel;” (2) SSPC-PA 2, “Measurement of Dry Coating Thickness with Magnetic Gages;” (3) SSPC-PA Guide 3, “A Guide to Safety in Paint Application;” (4) SSPC-PA Guide 4, “Guide to Maintenance R

3、epainting with Oil Base or Alkyd Painting Systems;” (5) SSPC-PA Guide 5, “Guide to Maintenance Coating of Steel Structures for Atmospheric Service;” SSPC-PA 6, “Fiberglass-Reinforced Plastic (FRP) Linings Applied to Bottoms of Carbon Steel Aboveground Storage Tanks;” SSPC-PA 7, “Applying Thin Film C

4、oatings to Concrete;” and SSPC-PA 8, “Thin-Film Organic Linings Applied in New Carbon Steel Process Vessels.” SSPC-PA 6 and PA 8 are jointly issued as NACE No. 10 and No. 11, respectively.2. SSPC-PA 1, “Shop, Field, and Maintenance Painting of Steel”This specication should be used when paint service

5、 is severe or when rigid requirements for appearance are estab-lished. When painting is necessary for protection from corrosive environments or for good appearance, then it is in the best interests of the purchaser to see that paint is applied in strict conformance with good practice. While surface

6、preparation is probably the most critical factor that governs the performance of paints, improper paint application may result in paint failure, even over blast cleaned surfaces.The specication covers pre-application procedures that are necessary before actual application of paint can begin. They in

7、clude handling and use of materials, surface prepara-tion, and proper mixing and thinning of paints. Also, general conditions for good application are covered in detail and include proper air temperature, moisture, humidity, cover, and surface temperature.SSPC-PA 1 permits application by brush, air

8、spray, airless spray, hot spray, plural component spray, high volume low pressure spray, or a combination of these methods. Roller coat applications may be used over at or slightly curved steel surfaces.Inspection procedures for paint applications are discussed in detail in Volume 1 of the SSPC Pain

9、ting Manual and in , “The Inspection of Coatings and Linings, A Handbook of Basic Practice for Inspectors, Owners, and Speciers.”3. SSPC-PA 2, “Measurement of Dry Coating Thickness With Magnetic Gages”This document describes the types of magnetic gages available, how to verify the calibration of the

10、 gages, and procedures to use in measuring the dry lm thickness of paint on steel.The gages are classied as either Type 1 pull-off gages or Type 2 electronic gages. Both are magnetic gages and measure the thickness of dry lm of a non-magnetic coating applied on a magnetic substrate.This standard spe

11、cies the number of measurements to be made to determine compliance with the specied minimum and maximum dry lm thicknesses.The 2004 revision includes some changes and additions, as listed below. Changes in gage terminologyThe procedure for dealing with a non-conforming area when measuring large stru

12、ctures has been modied. As before, only one 100 ft2(10 m2) area need be measured in each 1000 ft2(100 m2). In the previous version of PA 2, “additional measurements must be made to isolate the non-conforming area.” Added to that sentence in this latest version is “and each 100 ft2(10 m2) area painte

13、d during that work shift shall be measured.” The idea behind this change is that nding one non-conforming area indicates that something went wrong during that work shift. Therefore, there is no way of knowing how many other areas are non-conforming unless they are all measured.Gage accuracy has been

14、 changed from 10% to 5%. Contracting parties must now agree whether pen gages, which normally do not meet the 5% accuracy requirement, are permitted.The “Denitions” section has been expanded. A clear distinction is made between calibration (normally done by the gage manufacturer) and adjustment (don

15、e by the user).Two sample protocols for measuring the DFT on beams and girders is given in Appendix 3. The full DFT determina-tion requires ve spot measurements on each surface of the beam, while the less stringent sample determination requires only two or three spot measurements on each surface. Th

16、e committee recognized that the existing PA 2 was appropriate for large at surfaces, but there were some concerns when the method was applied to more irregular shapes. Although appendices are not require-ments of PA 2, they were written in such a way that they can be referenced in a job specication.

17、7-2SSPC-PA COMNovember 1, 2004Appendix 4 is similar to Appendix 3 except that it refers to beams or miscellaneous parts painted as a laydown in a shop. Protocols are given for two levels of DFT determina-tion. It is suitable for referencing in a job specication.Protocols for measuring DFT on test pa

18、nels are given in Appendices 5 and 6. The small size of test panels does not t well with the usual PA 2 procedure of making ve spot measurements per 100 ft2(10 m2). This is obviously for lab work and not for eld use. Appendix 5 species the number of gage readings for each test panel and Appendix 6 s

19、pecies how many gage readings to take in the special case of a blast cleaned test panel with a thin coating.4. SSPC-PA Guide 3, “A Guide to Safety in Paint Application”This guide, currently under revision, has been prepared so that the user will have information available when preparing a section on

20、 safety for a procurement document. The guide covers in considerable detail the necessary precautions to be taken in order to protect personnel and property from accidents due to falls, toxic fumes, res, explosion,etc. in the applica-tion of coatings to steel structures. Also covered is protective e

21、quipment to be used by the workers. Safety precautions are given for the equipment for applying paint and also for the equipment for providing access to the work area.5. SSPC-PA Guide 4, “Guide to Maintenance Repainting with Oil Base or Alkyd Painting Systems”This guide has been prepared specically

22、for use in repainting with oil base, alkyd, and other solvent-thinned paint systems. It is concerned with procedures necessary to maintain previously painted steel structures so that they continue to provide the corrosion protection as originally intended. Items covered are determining when maintena

23、nce painting is required and preparing the existing surface for painting.6. SSPC-PA Guide 5, “Guide to Maintenance Coating of Steel Structures for Atmospheric Service”This guide, intended for use primarily by the owners repre-sentative, covers procedures for developing a maintenance painting program

24、 for steel structures. It may be used for one time repaint programs or long range repaint programs.Planning and implementing maintenance painting programs is presented in a logical sequence of six specic steps. These steps range from assessing the initial condition of the structure to follow-up acti

25、vities required to implement an on-going maintenance program. Each step is designed such that it may be utilized in sequence with other steps, or inde-pendently for those with interest in only one or a few aspects of the program.7. SSPC-PA 6/NACE No. 10, “Fiberglass-Reinforced Plastic (FRP) Linings

26、Applied to Bottoms of Carbon Steel Aboveground Storage Tanks”This standard recommended practice species the proce-dures to design, apply, and inspect berglass-reinforced plastic (FRP) linings that are applied internally to the bottom of carbon steel aboveground storage tanks (ASTs). PA 6 includes se

27、ctions on lining materials, tank repair and preparation, applicator qualications, surface preparation, holding primer, caulking, laminate application, and roof leg bearing plates and a section on lining inspection, testing, and repair.8. SSPC-PA 7, “Applying Thin Film Coatings to Concrete”This stand

28、ard covers methods and procedures for applying thin lm organic coatings to concrete surfaces by brush, roller, or spray. It is not intended for coatigs applied to concrete oors or similar surfaces where thick coatings or surfacings are applied by trowel or mechanical equipment. Among the topics addr

29、essed are materials handling, mixing, thinning, moisture, temperature, topcoating, surface porosity, coating thickness, continuity, and various methods of application.9. SSPC-PA 8/NACE No. 11, “Thin-Film Organic Linings Applied in New Carbon Steel Process Vessels”This standard covers methods and pro

30、cedures for applying thin lm (less than 500 m 20 mils) organic coatings to new steel vessels. Among the topics addressed in this standard are lining materials, vessel fabrication and preparation, applicator qualications, surface preparation, lining application, and inspection and repair of vessel lining.