1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 28763:2011Vitreous and porcelain enamels Regenerative, enamelledand packed panels for air-gasand gas-gas heat exchangers Specifications (ISO 28763:2008)BS EN ISO 28763:
2、2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 28763:2011. It is identical to ISO 28763:2008. It supersedes BS EN 14866:2005, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e S T I / 3 6 ,
3、V i t r e o u s e n a m e l c o a t i n g s .A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978
4、 0 580 72286 8 ICS 25.220.50 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2011.Amendments issued since publicationDate T e x t a f f e c t e dEUROPEA
5、N STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 28763 March 2011 ICS 25.220.50 Supersedes EN 14866:2005English Version Vitreous and porcelain enamels - Regenerative, enamelled and packed panels for air-gas and gas-gas heat exchangers - Specifications (ISO 28763:2008) maux vitrifis - changeurs ther
6、miques pour rchauffeurs air-gaz et gaz-gaz empilement de panneaux maills remplaables et dmontables - Spcifications (ISO 28763:2008) Emails und Emaillierungen - Regenerative, emaillierte und gepackte Bleche fr Luft-Gas- und Gas-Gas-Wrmeaustauscher - Anforderungen (ISO 28763:2008) This European Standa
7、rd was approved by CEN on 3 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such
8、 national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own
9、language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
10、 Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 B
11、russels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 28763:2011: EBS EN ISO 28763:2011 EN ISO 28763:2011 (E) 3 Foreword The text of ISO 28763:2008 has been prepared by Technical Committee ISO/TC 107 “Metallic and other
12、inorganic coatings” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 28763:2011 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which is held by BSI. This European Standard shall be given the status of a nation
13、al standard, either by publication of an identical text or by endorsement, at the latest by September 2011, and conflicting national standards shall be withdrawn at the latest by September 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of pa
14、tent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14866:2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European
15、 Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the U
16、nited Kingdom. Endorsement notice The text of ISO 28763:2008 has been approved by CEN as a EN ISO 28763:2011 without any modification. BS EN ISO 28763:2011ISO 28763:2008(E) ISO 2008 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references1 3 Terms and definitions .2 4 Steel
17、substrates.3 4.1 Delivery.3 4.2 Analysis 3 4.3 Hydrogen permeability3 4.4 Fish scale test3 4.5 Pickling speed4 5 Enamel frit(s)4 5.1 Delivery.4 5.2 Coefficient of expansion.4 5.3 Fusion flow.4 5.4 Boiling water vapour resistance 4 5.5 Acid resistance 4 5.6 Thermal shock resistance 5 5.7 Adherence 5
18、6 Characteristics of the enamel coating 5 6.1 Adherence 5 6.2 Thickness .5 6.3 Thermal shock resistance 6 6.4 Fundamental defects.6 6.5 Open defects7 6.6 Edge covering of gas-gas heaters.7 6.7 Boiling sulphuric acid resistance 7 6.8 Rework7 7 Characteristics after packing .8 7.1 Packing pressure.8 7
19、.2 Visual examination 8 7.3 Edge covering of gas-gas heaters.8 8 Documentation.8 Annex A (normative) Method for determining thermal shock resistance of vitreous or porcelain enamel coatings.10 BS EN ISO 28763:2011ISO 28763:2008(E) iv ISO 2008 All rights reservedForeword ISO (the International Organi
20、zation for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been establishe
21、d has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
22、International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Pub
23、lication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent
24、 rights. ISO 28763 was prepared by the European Committee for Standardization (CEN) (as EN 14866) and was adopted, under a special “fast-track procedure”, by Technical Committee ISO/TC 107, Metallic and other inorganic coatings, in parallel with its approval by the ISO member bodies. BS EN ISO 28763
25、:2011INTERNATIONAL STANDARD ISO 28763:2008(E) ISO 2008 All rights reserved 1Vitreous and porcelain enamels Regenerative, enamelled and packed panels for air-gas and gas-gas heat exchangers Specifications 1 Scope This International Standard specifies the minimum requirements and the functional charac
26、teristics of enamel coatings applied by any process, such as wet dipping, wet flow-coating, wet spraying, wet electrostatic spraying, wet electrodeposition or dry-powder electrostatic spraying, to profiled steel heat exchanger panels in regenerative heat exchangers, before and after packing in baske
27、ts. For very severe service conditions, or to obtain extended operational life, more stringent limits may be agreed between customer and supplier. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition
28、cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 105-J03, Textiles Tests for colour fastness Part J03: Calculation of colour differences (including Technical Corrigendum 1:1996 and Technical Corrigendum 2:2006) ISO 2178, Non
29、-magnetic coatings on magnetic substrates Measurement of coating thickness Magnetic method ISO 4534, Vitreous and porcelain enamels Determination of fluidity behaviour Fusion flow test ISO 7991, Glass Determination of coefficient of mean linear thermal expansion ISO 8289:2001, Vitreous and porcelain
30、 enamels Low voltage test for detecting and locating defects ISO 28706-2:2008, Vitreous and porcelain enamels Determination of resistance to chemical corrosion Part 2: Determination of resistance to chemical corrosion by boiling acids, boiling neutral liquids and/or their vapours ISO 28723, Vitreous
31、 and porcelain enamels Determination of the edge covering on enamelled steel plate to be used in heat exchangers ISO 28764, Vitreous and porcelain enamels Production of specimens for testing enamels on sheet steel, sheet aluminium and cast iron EN 10204:2004, Metallic products Types of inspection do
32、cuments EN 10209:1996, Cold rolled low carbon steel flat products for vitreous enamelling Technical delivery conditions BS EN ISO 28763:2011ISO 28763:2008(E) 2 ISO 2008 All rights reserved3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 bliste
33、rs localized bubbles under the surface of the fired enamel 3.2 burn-off localized areas of rough black oxide erupting through the enamel coating 3.3 chipping fracturing and detachment of particles from a vitreous enamelled surface 3.4 copperheads small freckle-like or pimple-like reddish-brown spots
34、 occurring in ground-coats or in direct-on enamels applied to sheet metals 3.5 cracking laminar interruptions in the fused coating usually running vertical to the surface NOTE 1 The laminar interruptions can also occur at different angles. NOTE 2 Their causes are mainly the result of tensile stresse
35、s within the enamel coating. 3.6 crazing fine cracks in the enamel coating 3.7 fire tool marks fire marks small indentations similar in appearance to shallow pinholes 3.8 fish-scaling small half-moon-shaped defects occurring in the vitreous enamelled surface NOTE Fish-scaling can occur immediately o
36、n cooling or after some time has elapsed following firing. These defects originate from supersaturation of the substrate with hydrogen (acquired during firing) that suddenly fractures the enamel coating in order to relieve the pressure that has accumulated with time at the enamel-steel interface. 3.
37、9 spalling spontaneous fracturing and detachment of particles of enamel from within the coating layer NOTE Spalling often occurs on corners, sharp radii or panel edges and is the result of too low an enamel coefficient of expansion for the substrate, the external radii and the enamel thickness conce
38、rned. Thermal stresses can aggravate the spalling. 3.10 tearing short breaks or cracks in the enamel bisque that have healed during firing BS EN ISO 28763:2011ISO 28763:2008(E) ISO 2008 All rights reserved 33.11 air-gas heater heat exchanger used to heat up the air needed for combustion in the boile
39、r, using the combustion gases from the boiler as the hot fluid NOTE 1 The maximum temperature of the hot gases entering the heat exchanger is 450 C with a normal operating temperature from 380 C to 320 C. NOTE 2 Air-gas heat exchangers through which gases from DeNOx installations pass are considered
40、 as gas-gas heaters for the purposes of this International Standard. 3.12 gas-gas heater heat exchanger used in desulfuration plants to reheat the gases treated in the scrubber to obtain the proper draft in the stack NOTE 1 The hot gases are the untreated gases going to the scrubber. NOTE 2 The maxi
41、mum temperature of the hot gases entering the heat exchanger is 200 C with a normal operating temperature from 160 C to 120 C. 4 Steel substrates 4.1 Delivery The steel for enamelling shall conform to the requirements of EN 10209 and shall be delivered with a certificate in accordance with 3.1 of EN
42、 10204:2004. 4.2 Analysis The chemical composition shall be determined by a ladle analysis and shall conform to the requirements of EN 10209:1996, Table 2. At the request of the enameller, other elements as mentioned in Table 2 of EN 10209:1996 shall be agreed with the steel manufacturer. For grades
43、 DCO3ED and DCO4ED, the carbon content of the product shall be determined and shall conform to EN 10209:1996, Table 2. 4.3 Hydrogen permeability The hydrogen permeability shall have a minimum TH value of 100, calculated in accordance with EN 10209:1996, B.1.8, Equation (1), or shall give the result
44、of a minimum of 8 min in accordance with EN 10209:1996, B.1, calculated in accordance with B.1.8, Equation (2). In the absence of a certificate from the steel supplier confirming the above minimum hydrogen permeability, and with prior agreement between the customer and the supplier, the fish-scale r
45、esistance shall then be determined as described in 4.4. The hydrogen permeability method is not acceptable for the steel grades DCO6EK and DCO6ED (see EN 10209:1996, Table 2). For these grades, the fish-scale test described in 4.4 shall be used. 4.4 Fish-scale test The fish-scale test shall be carri
46、ed out in accordance with EN 10209:1996, B.2, method B.2. The test sheet (150 mm coil width) shall be pre-treated without a nickel dip. The front and back shall be coated with enamel prepared in accordance with the suppliers milling formula and applied to produce a fired thickness of 100 m to 130 m.
47、 After drying, the coated test sheet shall be fired for 5 min at 820 C. The test sheet shall then be subjected to thermal treatment at 60 C to 80 C for 24 h and subsequently inspected for fish scales. No fish scales are allowed. BS EN ISO 28763:2011ISO 28763:2008(E) 4 ISO 2008 All rights reserved4.5
48、 Pickling speed If required by the enameller, the pickling speed shall be determined in accordance with EN 10209:1996, Annex C, and an acceptable level shall be agreed with the steel manufacturer. 5 Enamel frit 5.1 Delivery Enamel frit shall be ordered by the enameller with a certificate conforming
49、to the requirements of 3.1 of EN 10204:2004, including the results for the items given under 5.5 and 5.7. The tests in 5.4 and 5.6 shall be carried out whenever there is a change in the frit or a change in the milling formula. When taking delivery of “ready to use” enamel, enamel slip or enamel powder, the enameller can ask for additional requirements for the application properties in the certificate. Any other requirements and the test recipes shall be determined by consultation between t
