1、SSPC-PA Guide 5September 1, 2002Editorial Revisions November 1, 20047-531. Scope1.1 This guide covers procedures for developing a main-tenance coating program for steel structures. The guide may be used for one-time recoat programs or long-range recoat programs.1.2 The guide is intended for use prim
2、arily by owners representatives. It is not intended to be a do-it-yourself guide, but is representative of the processes that a coating specialist (such as a Protective Coating Specialist PCS certied by SSPC) would follow to develop a maintenance coating plan for specic facilities.2. Description2.1
3、A maintenance coating program is required to prevent corrosion of steel and deterioration of other substrates. It is also required to maintain an acceptable appearance of coated structures. Decisions on frequency and extent of recoating and type of system to be used require consideration of numerous
4、 factors, including both technical and economical alterna-tives.2.2 This guide sets out specic steps that may be used, either individually or collectively, to identify and address essential elements of a maintenance coating program. These steps are summarized in Section 4. Preparation of a contract
5、specication for coating work is covered in SSPC-TR 4/NACE 80200, “Preparation of Protective Coating Specications for Atmospheric Service” (latest edition).1Due to wide variations in procedures, a discussion of contracting methodologies and implementation schemes is outside the scope of this guide. 2
6、.3 MAJOR STEPS IN MAINTENANCE COATING: This guide addresses six major steps in a maintenance coating program, which are dened as: Plan and Conduct Condition Assessment Survey (Section 5) List Potential Maintenance Painting Options (Section 6) Evaluate Economics of Available Options (Section 7) Selec
7、t Appropriate Maintenance Painting Options and Establish Implementation Procedures (Section 8) Implement Maintenance Painting Options (Section 9) Plan and Implement Follow-Up Activities (Section 10)3. Referenced Standards3.1. SSPC STANDARDS AND JOINT STANDARDS1Items preceded by an asterisk (*) are r
8、eferenced in the Notes or Appendices.Guide 6 Guide for Containing Debris Generated During Paint Removal OperationsGuide 7 Guide for the Disposal of Lead-Contaminated Surface Preparation DebrisGuide 14 Guide for the Repair of Imperfections in Galvanized or Inorganic Zinc Coated Steel with Organic Zin
9、c-Rich PaintPA 2 Measurement of Dry Coating Thick-ness with Magnetic GaugesPA Guide 4 Guide to Maintenance Repainting with Oil Base or Alkyd Painting SystemsPA 1 Shop, Field, and Maintenance Painting of SteelSP 1 Solvent CleaningSP 2 Hand Tool CleaningSP 3 Power Tool CleaningSP 5/NACE No. 1 White Me
10、tal Blast CleaningSP 6/NACE No. 3 Commercial Blast CleaningSP 7/NACE No. 4 Brush-Off Blast CleaningSP 10/NACE No. 2 Near-White Blast CleaningSP 11 Power Tool Cleaning to Bare MetalSP 12/NACE No. 5 Surface Preparation and Cleaning of Metals by Waterjetting Prior to RecoatingSP 14/NACE No. 8 Industria
11、l Blast CleaningSP 15 Commercial Grade Power Tool Cleaning * QP 1 Standard Procedure for Evaluat-ing Painting Contractors (Field Application to Complex Industrial Structures)SSPC: The Society for Protective CoatingsPAINT APPLICATION GUIDE NO. 5Guide to Maintenance Coating of Steel Structuresin Atmos
12、pheric Service1 Joint standards may alo be obtained from NACE International at http:/www.nace.orgSSPC-PA Guide 5September 1, 2002Editorial Revisions November 1, 20047-54* QP 2 Standard Procedure for Evaluat-ing the Qualication of Painting Contractors (Field Removal of Hazardous Coatings from Complex
13、 Industrial Structures)* QP 5 Standard Procedure for Evaluating Qualications of Coating and Lining Inspection CompaniesTR 4/NACE 80200 Preparation of Protective Coating Specifications for Atmospheric Service TU 3 OvercoatingTU 4 Field Methods for Retrieval and Analysis of Soluble Salts on Sub-strate
14、sVIS 2 Standard Method of Evaluating Degree of Rusting on Painted Steel Surfaces3.2 ASTM INTERNATIONAL STANDARDS:2* D 3276 Standard Guide for Painting Inspectors (Metal Substrates)* D 4228 Standard Practice for the Qualication of Coating Applicators for Application of Coatings to Steel SurfacesD 610
15、 Standard Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces3.3 FEDERAL STANDARD3Code of Federal Regulations29 CFR 1926.62 Lead (Construction Industry Standard)4. Planning and Use of Guide4.1 This document is based on, and is intended to be used with, the technical principles out
16、lined in SSPC-TU 3. Planning and implementation of maintenance coating programs for steel structures are presented in a logical sequence of six specic steps. These steps range from planning and conducting condi-tion assessment to follow-up activities required for implementing an on-going maintenance
17、 program. Each step is designed such that it may be utilized in sequence with the other steps, or independently for those with interest in only one or a few aspects of the program. A summary of each step follows.4.1.1 Plan and Conduct Condition Assessment Survey (Step 1): Section 5 provides a genera
18、l approach for organizing surveys to evaluate the condition of the structure. Three different types of surveys (general overview, detailed visual survey, and physical inspection) are covered, along with a proposed plan for assessing sub-units of a larger, more complex structure, and a description of
19、 procedures and documentation needed.4.1.2 List Potential Maintenance Painting Options (Step 2): Section 6 reviews the various maintenance painting options available, including: spot repair, overcoating, and complete recoat, as well as the rationale for selecting these maintenance painting options a
20、nd the types of information needed for the decision. 4.1.3 Evaluate Economics of Available Options (Step 3): Section 7 provides guidance in evaluating the initial and life-cycle costs of available maintenance painting options. Each decision has potential impact on the life cycle cost of the coating
21、system and must be identied and evaluated. 4.1.4 Select Appropriate Maintenance Painting Options and Establish Implementation Procedures (Step 4): Section 8 reviews the factors and considerations necessary to establish specications for the two major maintenance painting options of spot repair and co
22、mplete recoat, including identication of relevant factors for coating system selection, and surface preparation selection, depending on whether complete removal and recoat, spot repair, or a combination of spot repair and overcoating is selected as a strategy.4.1.5 Implement Maintenance Painting Opt
23、ions (Step 5) Section 94.1.6 Plan and Implement Follow-Up Activities (Step 6): Section 10 describes procedures and review actions after the job is completed, including documentation, short- and long-term condition inspections, and preventative maintenance measures.5. Plan and Conduct Condition Asses
24、sment Survey (Step 1)5.1 PURPOSE OF CONDUCTING CONDITION ASSESSMENT SURVEY: Condition assessments can be used for several purposes, i.e., to determine the need for recoating, to determine the extent of corrosion and corrosion damage, to determine the performance of various coating systems, or to pri
25、oritize coating requirements where insufcient funds are available to do all the desired work (see Note 11.1). 5.2 IDENTIFY AND INVENTORY STRUCTURES TO BE SURVEYED: A written description of the structures requiring maintenance coating should be obtained or prepared. The description should include loc
26、ation, dimensions, type of substrate, conguration, process, previous surface prepara-tion and coating plans, specications, history, and any other pertinent information. Examples of the latter would include proximity to sensitive areas, planned new construction or other activities nearby, and types o
27、f exposures (e.g., acid fallout). (See SSPC Publication 94-18, Project Design.) It is usually 2ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2659. Available onliine from www.astm.org.3FED STD 141 can be obtained from http:/astimage.daps.dla.mil/online/new/SSPC-PA Guide 5Sept
28、ember 1, 2002Editorial Revisions November 1, 20047-55most economical to consider all structures in similar condi-tion within a given area for maintenance at the same general time.5.3 DETERMINE THE EXTENT OF ASSESSMENT REQUIRED: The survey may vary considerably in the extent and detail of the informa
29、tion required. Among the types of survey to be considered are: 5.3.1 General Coating Condition Assessment: In this assessment, usually only one or two parameters are rated (e.g., general condition or rusting). The structure is normally observed from the ground (i.e., without scaffolding). The assess
30、-ment is at best a qualitative rating of the condition (e.g., good, fair, poor). Only the major features of a structure or facility are rated (e.g., a full span of a bridge or a side of a storage tank). This type of assessment is usually done in a few hours or less and is suitable for identifying ov
31、erall condition of the coating.5.3.2 Detailed Visual Assessment: This type of assess-ment also relies exclusively on visual observations, but these are performed more systematically than for a general assess-ment. Numerous structural elements (e.g., support beams, connections, edges) are separately
32、rated according to SSPC-VIS 2, ASTM D 610, or equivalent and combined to provide an overall structure or facility rating. Often, several condition parameters (e.g., loss of topcoat, cracking, rust staining) and several corrosion parameters (e.g., rusting, blistering, scaling, loss of metal) are reco
33、rded. With this survey, one can obtain a semi-quantitative rating of the percent of surface deteriorated. This type of survey may be used to develop preliminary cost estimates for recoating. 5.3.3 Physical Coating Testing: Physical testing, visual assessment, and the general assessment are often per
34、formed simultaneously. Visual assessment gives no information on the lm adhesion, thickness, brittleness, or underlm corrosion. Physical testing is required to determine whether the coating can be overcoated or repaired, or whether it is too weak to accept another coating layer. This assessment shou
35、ld be performed prior to specifying the maintenance painting options and requires direct access to the surface at several locations on the structure. SSPC-TU 3 provides discussion of the value of physical testing, as well as the procedures for testing.Identication of the generic type of the existing
36、 nish coating is important when selecting compatible coatings for maintenance coating, if part of the existing coating is to remain. A laboratory technique, Fourier Transform Infrared Spectroscopy (FTIR), is frequently used to determine the generic coating type. This requires only a tiny sample chip
37、 of paint to identify the coating type, and is available at a nominal price. Alternatively, patch tests of the proposed system or systems may be applied to the existing coating to establish compatibility. 5.3.4 Hazardous Content Assessment: Unless previous coating history and specications are known,
38、 laboratory testing needs to be performed to determine if any hazardous elements are present. These include, but are not limited to, lead, cadmium, and chromium. OSHA (Occupational Safety and Health Administration) requirements for worker expo-sure and RCRA (Resource Conservation and Recovery Act) r
39、equirements for disposal with its implied containment should be incorporated into the contract to protect workers and lessen potential claims. SSPC-Guide 6 and Guide 7 provide details relevant to containment and disposal. OSHA regulation 29 CFR 1926.62 details worker protection requirements for lead
40、 (see SSPC publication 95-06, Project Design).5.3.5 Structural Inspection: Coating assessment should be included as part of any general structural inspection for loss of metal, broken joints, or other structural defects. A relatively small additional inspection time is required to evaluate and recor
41、d the ratings of individual structures or structural elements. This information will normally prove extremely valuable in evaluating maintenance painting options, especially in developing the most cost effective life-cycle maintenance strategy. Numerous public and private entities have been successf
42、ul in using scheduled facility inspections, such as bridge safety inspections, as the “rst cut” in determining coating condition.5.4 DETERMINE THE CONDITION RATING SCHEME: For both visual inspection and physical testing, it is necessary to use a standard rating system and format for recording data.
43、SSPC-TU 3 discusses the salient characteristics of a rating scheme that is based on the technical merits of coating condi-tion and overcoating. 5.4.1 Physical Testing: See SSPC-TU 3 for detailed guid-ance in evaluating coating condition and risks of overcoating. These evaluations generally require c
44、ertain detailed information concerning the coating type and physical condition.5.4.2 Use of Ratings Data: In many cases, these condi-tion ratings will be keyed directly to repair procedures (e.g., SSPC-PA Guide 4). The next two sections of this guide give the procedures for developing such a scheme.
45、5.5 PLAN FOR INSPECTING STRUCTURAL COMPONENTS: A sub-unit sampling plan identies the portions of the structure or facility that will be rated and the type of rating scheme to be used. Sub-unit sampling plans are needed for complex structures or where detailed information is required. For a process u
46、nit, (for example) the structural steel might be divided into individual tanks, piping, handrails and ladders, and structural support. On large structures, the areas could be further subdivided into sections. Because of differences in corrosion tendencies, it is often useful to have SSPC-PA Guide 5S
47、eptember 1, 2002Editorial Revisions November 1, 20047-56separate ratings for edges and at surfaces. The extent of inspection depends on how detailed a survey is desired and what resources may be available. 5.6 ESTABLISH PROCEDURES AND ASSEMBLE RELATED DOCUMENTS5.6.1 A specic procedure should be esta
48、blished for a condition assessment, which should include a budget and schedule, including equipment and crews. The availability of funds will determine the extent of the survey that can be undertaken. A schedule should be established based on the number of hours or days required to prepare the struc
49、ture (e.g., notify other trades) or arrange for access (i.e., coordinate schedules of other individuals). This includes identifying support crews and equipment that may be required to assist with the condition assessment. Personnel requirements must also be established (i.e., identify individuals who will conduct the survey such as in-house inspectors, engineers, outside consultants, coating contractors, or coating manufacturers). If a condition assessment survey is to be performed by a consultant or contractor, a written contract should be prepared. If a coa
