Detail of NB/T 47055-2017

Introduction of NB/T 47055-2017

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization—Part 1: Structure and drafting of standards. This standard replaces JB/T 1615-1991 Painting and packing specification of boiler. The following technical changes have been made with respect to JB/T 1615-1991: ——Some normative references are added; ——The requirements of surface preparation are added (see Clause 3 hereof); ——The requirements of painting technology are detailed; ——The requirements of film thickness for different components are added; ——The requirements of packing principle are added; ——The requirements of packing method are added; ——The requirements of packing documents, marks and product identification are detailed; ——The requirements of inspection are added; ——The supplementary requirements for painting of steel structure components in Annex A (Informative) are added; ——The models and names of commonly used paints and anti-rust paints are deleted. This standard was proposed by and is under the jurisdiction of Committee National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262). The previous editions of the standard replaced by this standard are as follows: ——JB 1615-1983; ——JB/T 1615-1991. Painting and packing specification of boiler 1 Scope This standard specifies the painting and packing specification of finished boiler products. This standard is applicable to the painting and packing of boiler products and their accessories (spare parts). Any special requirements for the painting and packing of product shall be stated in the order contract. This standard may also be served as a reference for the painting and packing of organic heat carrier boilers and other boiler products. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendment) applies. GB 146.1 Rolling stock gauge for standard gauge railways GB 191 Packaging—Pictorial markings for handling of goods GB/T 2934 General-purpose flat pallets for through transit of goods—Principal dimensions and tolerances GB/T 5210 Paints and varnishes—Pull-off test for adhesion GB 6514 Safety code for painting—Safety, ventilation and air clean-up for painting process GB/T 7284 Wooden framed case GB 7692 Safety code for painting—Safety, ventilation and air clean-up for pretreatment process of painting GB/T 8923.1 Preparation of steel substrates before application of paints and related products—Visual assessment of surface cleanliness—Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings GB/T 8923.2 Preparation of steel substrates before application of paints and related products—Visual assessment of surface cleanliness—Part 2: Preparation grades of previously coated steel substrates after localized removal of previous coatings GB/T 8923.3 Preparation of steel substrates before application of paints and related products—Visual assessment of surface cleanliness—Part 3: Preparation grades of welds edges and other areas with surface imperfections GB/T 9286 Paints and varnishes—Cross cut test for films GB/T 13288.1 Preparation of steel substrates before application of paints and related products—Surface roughness characteristics of blast-cleaned substrates—Part 1: Specifications and definitions for ISO surface profile comparators for the assessment of abrasive blast-cleaned surfaces GB/T 13384 General specifications for packing of mechanical and electrical product GB/T 13452.2-2008 Paints and varnishes—Determination of film thickness GB/T 13912 Metallic coatings—Hot dip galvanized coatings on fabricated iron and steel articles—Specifications and test methods GB/T 17850.1 Preparation of steel substrates before application of paints and related products—Specifications for non-metallic blast-cleaning abrasives—General introduction and classification GB/T 18570.3 Preparation of steel substrates before application of paints and related products—Tests for the assessment of surface cleanliness—Part 3: Assessment of dust on steel surface prepared for painting (pressure-sensitive tape method) GB/T 18838.1 Preparation of steel substrates before application of paints and related products—Specifications for metallic blast-cleaning abrasives—General introduction and classification 3 Painting 3.1 General 3.1.1 Painting and packing shall be carried out after the boiler products are manufactured and inspected as acceptable. 3.1.2 The painting of boiler products is divided into two types: the painting of boiler steel structure components and the painting of boiler general components (other than steel structure components). 3.1.3 The boiler steel structure components include steel frame (column, beam, roof, vertical support, horizontal support, etc.), rigid beam, platform, escalator, railing, roof frame, etc. Painting of structural parts such as steel structures in front of, behind and on the side of furnace, steel structures between coal bunkers, denitration steel structures, dust collector steel structures, desulfurization island steel structure, elevator shaft steel structure and hanging device can be carried out with reference to that of steel structure components. 3.1.4 The painting according to this standard shall be economical and beautiful, and can guarantee the surface protection of the product for 6 months. If longer surface protection is required, it shall be negotiated between the supplier and the purchaser. 3.2 Paints 3.2.1 The paints shall meet the requirements of corresponding product standards. The paints shall also meet the requirements of national safety and environmental protection. 3.2.2 The paints shall have complete identification, factory certificate, product manual and chemical safety manual. 3.2.3 The paints shall be free from aging phenomena such as thickening, caking, gelatinization, precipitation, crusting and turbidity. 3.2.4 The paint series shall be selected in accordance with those specified in Table 1. Other paints with the series same as those specified in Table 1 may also be selected. Table 1 Common paint series Paint type Paint series Paint name Primer Alkyds Various alkyd primer Inorganic paints Inorganic zinc silicate and inorganic zinc-rich paints Epoxy paints Epoxy zinc phosphate primer Epoxy zinc-rich primer Epoxy primer Polyurethanes Polyurethane primer Phenolics Phenolic primer Cold sprayed zinc paints Cold sprayed zinc primer Intermediate paint Epoxy paints Micaceous iron oxide epoxy intermediate paint Epoxy paste paint Finish Alkyds Various alkyd enamel Epoxy paints Epoxy finish Chlorinated rubber paints Chlorinated rubber finish Polyurethanes Aliphatic polyurethane finish Polyurethane finish Polysiloxane paints Polysiloxane finish Phenolics Phenolics finish Fluorocarbons Fluorocarbon finish Acrylic acid Acrylic acid finish Other special paints Various high-temperature resistant paint Grease Anti-rust grease Acid-free industrial vaseline Dural anti-rust grease Solderable paints   3.3 Surface preparation before painting 3.3.1 All metal surfaces to be painted shall be prepared according to different preparation grades. The prepared steel surface shall be free from grease, dirt, loose oxide scale, floating rust and other attachments affecting painting. 3.3.2 The surface preparation may be carried out by the following methods: a) Cleaning by hand or power tools It is applicable to metal surfaces with relatively low painting requirements or equipment restrictions that cannot be blasted, and is also applicable to the subsequent paint repair operations. The surface cleaned by hand or power tools shall not be less than the Grade St2 specified in GB/T 8923.1. b) Blasting treatment It is applicable to metal surfaces with high surface preparation requirements or products that are not suitable for surface preparation by other methods. The surface quality after blasting treatment shall not be lower than Grade Sa2 in GB/T 8923.1. Abrasives for blasting treatment shall meet the following requirements: 1) The metallic abrasives shall meet the requirements of GB/T 18838.1; 2) The non-metallic abrasives shall meet the requirements of GB/T 17850.1; 3) Abrasives with appropriate particle size shall be selected according to the requirements of surface roughness. 3.3.3 Surface imperfection treatment after painting shall be carried out according to GB/T 8923.3: for steel structure products, it shall not be lower than Grade P3; for general products, it shall not be lower than Grade P2. 3.3.4 The sealing surface shall be effectively isolated and protected before surface preparation, and anti-rust oil shall be applied in time after qualified surface preparation. 3.3.5 Different requirements of various types of paints for derusting grade of painting surface substrate shall be considered. 3.4 Painting requirements 3.4.1 The painting may be carried out by manual brush coating, roll coating, dip coating or blasting according to the structural shape and process requirements of the product. 3.4.2 Painting shall be carried out in time after surface preparation. Under normal cases, the coating should be applied to the surface to be painted within 4h after surface preparation; when the relative humidity of the environment is not more than 60%, it can be delayed appropriately, but the longest time shall not exceed 12h; no matter how long it stays, as long as the surface rusts, it shall be derusted again. 3.4.3 For more than two coatings, the time interval between the previous coating and the next coating shall meet the minimum coating interval. 3.4.4 The painting environment shall meet the requirements of GB 6514 and GB 7692, and the painting operation shall not be carried out in sun, dust, wind and snow, dense fog and other environments, and shall meet the following conditions unless otherwise specified: a) The ambient temperature for construction is 5°C to 38°C and the relative humidity is less than or equal to 85%; b) The substrate surface temperature is 3°C above dew point; c) When the construction environment temperature is –5°C to 5°C, the low-temperature curing products or other reliable measures shall be selected. 3.4.5 The configuration and use period of paints shall meet the following requirements: a) The paint shall be fully stirred and evenly mixed, with an electric or pneumatic stirring device to be recommended, before application. For a two-component or multi-component paint, all the components shall separately be mixed uniformly first, and then mixed together in strict proportion and stirred uniformly; b) The mixed paint shall be cured in accordance with the product manual; c) The service life of the paint shall be in accordance with the service life specified in the product manual. 3.4.6 Generally, the dry film thickness of each paint is controlled between 25 μm and 50 μm, and the thick build paint may be appropriately thickened, or it can be implemented in accordance with the paint product manual. 3.4.7 The thickness of each film shall be controlled, and the wet film and dry film thickness shall be inspected according to the inspection requirements. 3.4.8 In general, stainless steel and painted surfaces are not painted. Non-ferrous metal parts such as copper and aluminum are not painted or other surface protection methods such as grease and anti-rust grease are adopted. 3.4.9 Except for special requirements, the inner surface of steel structure members may not be painted, and sealing and anti-corrosion measures shall be taken for the steel structure ends of marine products. 3.4.10 The coating surface shall be uniform and shall be free from blistering, cracking, inclusions, wrinkled skin, grinning, peeling and variegated color. 3.4.11 The film shall be in good condition before the product is delivered. If the film is damaged due to handling and lifting in the factory, it shall be repainted with appropriate paint and painting process. 3.4.12 Before secondary painting (excluding galvanizing), the surface shall be prepared as follows: a) Repair the remaining parts of the original coating, including any primer and accompanying undercoat that adhere firmly after surface preparation, and shall be free from porosity and contaminants. The treatment grade after local removal of the original coating shall not be lower than the Grade P St2 specified in GB/T 8923.2; b) Wash the seaborne objects with water before re-painting to remove thoroughly the salt; c) Before on-site painting, thoroughly remove oil, mud, dust, etc. on the surface of objects. 3.4.13 After construction, the performance of film (film thickness, adhesion, etc.) shall be tested and judged according to relevant national standards. 3.4.14 In addition to the requirements specified in Table 2, the painting of the main components of the product shall also meet the following requirements: a) The pipe end and flange end face shall be sealed and packed with plastic cover, wood board or other materials; b) The flange end face, screw thread, screw hole and heat transfer component shall be painted with anti-rust oil for protection; c) The groove is painted with solderable paints (if required by the user); d) Stainless steel plate shall be used for shop-assembled boiler guard, and if color steel plate is adopted, protective measures shall be taken; e) The pipe end and pipe hole shall be protected by plastic cover or other materials; f) Depending on the characteristics of the paint used, the surface preparation requirements may be changed appropriately, but the anti-corrosion performance of the whole coating cannot be reduced.

Contents of NB/T 47055-2017

Foreword i 1 Scope 2 Normative references 3 Painting 4 Packing 5 Packing documents, marks and product identification 6 Inspection Annex A (Informative) Supplementary requirements for painting of steel structure components