1、 Standard Practice Maintenance Painting of Electrical Substation Apparatus Including Flow Coating of Transformer Radiators This NACE International standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any re
2、spect preclude anyone, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE standard is to be construed as granting any right, by implication or
3、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 letters patent. This standard represents minimum requirements and should in no way be interpreted as a
4、 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 this standard in specific instances. NACE assumes no responsibility for the interpretation or use of th
5、is standard by other parties and accepts responsibility for only those official NACE interpretations issued by NACE in accordance with its governing procedures and policies which preclude the issuance of interpretations by individual volunteers. Users of this NACE standard are responsible for review
6、ing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of m
7、aterials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE standard are also responsible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve
8、compliance with any existing applicable regulatory requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE standards are subject to periodic review, and may be revised or withdrawn at any time in accordance with NACE technical committee procedures. NACE requires that action be taken
9、to reaffirm, revise, or withdraw this standard no later than 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 standards may receive current information on all stand
10、ards and other NACE publications by contacting the NACE FirstService Department, 1440 South Creek Dr., Houston, TX 77084-4906 (telephone +1 281-228-6200). Revised 2012-06-23 Reaffirmed 2004-03-31 Approved 1997-06-27 NACE International 1440 South Creek Dr. Houston, Texas 77084-4906 +1 281-228-6200 IS
11、BN 1-57590-042-4 2012, NACE International NACE SP0297-2012 (formerly RP0297) Item No. 21081 SP0297-2012 NACE International i _ Foreword Aspects of normal industrial maintenance painting such as surface preparation, coating selection, application methods, and safety considerations are subject to enti
12、rely different rules when placed within the confines of an energized, high-voltage substation. With utilities and industries attempting to obtain maximum use of their systems, transmission and distribution apparatus are being pushed to the limits of their designed service life. Properly engineered a
13、nd implemented maintenance painting programs protect equipment from the detrimental effects of corrosion and help it perform to the fullest extent of its operating life. Maintenance personnel for utilities and large industrial concerns who are responsible for maintenance painting of electrical equip
14、ment are primarily electrical engineers or have their background in electrical work. These individuals often have little, if any, practical knowledge of corrosion and its control. Consequently, many specifications that are poorly written, incomplete, and technically inaccurate are being used. This s
15、tandard has been prepared to assist maintenance personnel responsible for painting electrical equipment. A sample specification is included in Appendix A (Nonmandatory). This specification provides an example of one of the many types of specifications currently used by the industry. NACE neither end
16、orses nor recommends the use of this sample specification. It is provided for information only. This standard was originally prepared in 1997 by NACE Task Group (TG) T-6H-50, a component of former Unit Committee T-6H on Coating Materials for Atmospheric Service. It was reaffirmed in 2004 by Specific
17、 Technology Group (STG) 02 on Protective Coatings and LiningsAtmospheric. It was revised in 2012 by TG 457, “Review of NACE Standard RP0297-2004.” TG 457 is administered by STG 02, “Coatings and Linings, ProtectiveAtmospheric.” This standard is issued by NACE under the auspices of STG 02. In NACE st
18、andards, the terms shall, must, should, and may are used in accordance with the definitions of these terms in the NACE Publications Style Manual. The terms shall and must are used to state a requirement, and are considered mandatory. The term should is used to state something good and is recommended
19、, but is not considered mandatory. The term may is used to state something considered optional. _ SP0297-2012 ii NACE International _ NACE International Standard Practice Maintenance Painting of Electrical Substation Apparatus Including Flow Coating of Transformer Radiators Contents 1. General . 1 2
20、. Purpose of Coating Electrical Substation Apparatus 1 3. Safety Considerations . 2 4. Surface Preparation for Radiators 2 5. Coating Selection 3 6. Application . 4 7. Inspection 4 8. Hazardous Waste Considerations 6 9. Contractor Qualification. 6 References 6 Appendix A: General Sample Transformer
21、Painting Specifications (Nonmandatory) 6 Appendix B: Alternating Current Minimum Safe Working Distances (A) (Mandatory) 10 _ SP0297-2012 NACE International 1 _ Section 1: General 1.1 This standard practice provides standards for preparing specifications and procedures for coating electrical substati
22、on apparatus. 1.2 This standard is designed to introduce owners, engineers, maintenance personnel, and contractors to the four aspects unique to substation coating: (a) Safety considerations (b) Surface preparation for radiators (c) Coating selection (d) Application (flow coating) 1.3 This standard:
23、 1.3.1 Informs the reader of the factors that make electrical substation coating unique among all other forms of industrial maintenance painting and highlights special factors such as worker safety and coating of radiators. 1.3.2 Provides owners, engineers, and maintenance personnel with a sample sp
24、ecification they may modify to meet their specific requirements. 1.4 This standard deals only with substation apparatus, which includes: (a) Transformers (b) Circuit breakers (all types) (c) Switchgear enclosures (d) Regulators (e) Potential transformers (f) Current transformers (g) Coupling capacit
25、or potential devices (CCPDs) 1.5 This standard does not include the painting of structural steel, fencing, buildings, or other miscellaneous items within the substations. _ Section 2: Purpose of Coating Electrical Substation Apparatus 2.1 Electrical substation apparatus is coated for one or more of
26、the following reasons: 2.1.1 To protect the metal portions of the apparatus from corrosion. 2.1.2 To help a substation blend in with the surrounding environment. 2.1.3 To improve the cosmetic appearance of the apparatus. 2.1.4 To improve or maintain the efficiency of transformer radiators. 2.1.5 To
27、draw attention to important indicators (e.g., circuit breakers or switch open/close indicators that tell operators whether a breaker is open meaning the circuit is cut out or closed meaning the circuit is in service) or dangerous high-voltage areas (e.g., breaker closure switches, bushing caps). SP0
28、297-2012 2 NACE International _ Section 3: Safety Considerations 3.1 No industrial maintenance painting project is exempt from safety considerations. Precautions that are taken on other jobs, such as fall protection, lockout/tagout procedures, worker protection from abrasive blasting and coating ope
29、rations, and all other typical precautions must also be observed when coating substations. However, working in a substation exposes personnel to a hidden and potentially fatal danger: High voltages and the associated lethal current. 3.2 Danger of Electrical Accidents: To be in danger of electrical s
30、hock it is not necessary to make actual physical contact with an energized conductor. The high voltages found in substations have the capability and the inclination to pass through air space to strike a worker. The actual amount of air space that may be spanned varies with the voltage. Minimum safe
31、working clearances from energized components are given in Appendix B (Mandatory). These clearances are determined in the United States by Occupational Safety and Health Administration (OSHA)(1) and other local or national codes or regulations may apply. 3.3 Existing Safety Procedures: All utilities
32、and many industrial customers have written procedures and policies designed to address the inherent danger when working in energized substations. 3.4 Each year workers are killed by electricity while working in substations. Many of those killed are experienced, trained utility personnel who work in
33、this type of environment every day. If a contractor is to be used to perform this work, his safety record must be evaluated. 3.5 Working on Energized Apparatus: Many utilities and companies have policies prohibiting working on energized apparatus. If work is allowed on energized equipment, the owner
34、 and contractor shall meet to determine whether work can be completed safely on the energized equipment in question. The owner must be completely satisfied as to the contractors ability to work on this equipment safely. The equipment shall be de-energized if there is any question as to the safety of
35、 the operation. 3.6 Safety Records: The owner shall investigate a contractors safety background (OSHA) 300 logs, which detail a companys safety record. The National Council on Compensation Insurances (NCCI)(2) experience modification rating (EMR) also can be an indicator of a companys safety record.
36、 An EMR rating of “1” is the baseline. A good safety record causes the rating to go down; accidents cause the rating to go up. _ Section 4: Surface Preparation for Radiators 4.1 It is not possible to physically access all the areas of radiators that require surface preparation. To complicate the pro
37、blem, the walls of radiators are manufactured with relatively thin metal (19 gauge or 0.0394 in) to enhance their ability to radiate heat from the transformer oil within them. Caution must be exercised when abrasive blasting accessible areas of the radiators to prevent blasting a hole through the th
38、in metal wall. Even greater care is needed when corrosion is present. 4.2 Damage to Porcelain: An additional concern when abrasive blasting is performed in a substation is possible damage to the glazed porcelain bushings on apparatus and the insulators on structural steel. Damage to these insulators
39、 can result in a loss of their insulating capabilities and a subsequent electrical failure. Abrasives used in blasting can easily damage or remove the glazing on these bushings and insulators, and they should be protected when blasting is performed near them. 4.3 Surface Preparation Methods 4.3.1 Ra
40、diators should be low-pressure washed with a solution of detergent and water to remove oil, dirt, salts, chalk, bird droppings, and other foreign matter on minimally rusted surfaces. 4.3.2 When sporadic rust is evident and has been observed in inaccessible areas, the surface should be washed in acco
41、rdance with Paragraph 4.3.1 and then treated with a mild acid (e.g., phosphoric) solution to passivate rusted areas. 4.3.3 When complete removal of the existing coating system is warranted because of widespread rusting, coating delamination, or other factors, a heated caustic solution should be appl
42、ied by the flow-coating method until all existing coatings have been removed to bare metal. The surfaces must then be treated with a mild phosphoric acid solution and rinsed with fresh water to neutralize the surface. _ (1) Occupational Safety and Health Administration (OSHA), U.S. Department of Lab
43、or, 200 Constitution Ave. NW, Washington, DC 20210. (2) National Council on Compensation Insurance (NCCI), 901 Peninsula Corporate Circle, Boca Raton, FL 33487-1362. SP0297-2012 NACE International 3 _ Section 5: Coating Selection 5.1 The selection of coatings for electrical equipment can be divided
44、into two areas: 5.1.1 Coatings for circuit breakers, regulators, and any relatively flat or accessible areas by conventional methods such as brush, roll, or spray application. 5.1.2 Coatings for inaccessible areas, such as radiators, which require flow coating. 5.2 A wide variety of high-performance
45、 coatings, both single-component and multi-component, may be used for coating all easily accessible items (surfaces other than radiators). 5.3 Coatings for Radiators (Flow Coatings) 5.3.1 Transformer radiators present unique accessibility problems, requiring flow coating with materials specifically
46、designed for flow-coating application. 5.3.2 The nature of the flow-coating process restricts the types of coatings that should be used. A key factor in successful flow coating is uniform coating viscosity and the ability to control this viscosity. If the viscosity of the coating being flowed change
47、s during the operation, coating uniformity and appearance are negatively affected. Not only does the dry film thickness vary, but large fluctuations in viscosity can cause areas of excessive film thickness that could result in future delamination. Therefore, only coatings capable of retaining a uniform viscosity throughout the flow-coating operation, or those in which viscosity can be adjusted without detrimental effects to the coating, should be used. 5.3.3 Commonly Used Flow Coatings: The most
