1、BSI Standards PublicationBS EN ISO 28721-2:2015Vitreous and porcelain enamels - Glass-lined apparatus forprocess plantsPart 2: Designation and specification ofresistance to chemical attack and thermal shockBS EN ISO 28721-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implem
2、entation of ISO 28721-2:2015. It supersedes BS EN ISO 28721-2:2011 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee STI/36, Vitreous enamel coatings.A list of organizations represented on this committee can be obtained on request to its secretary.This p
3、ublication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 86616 6 ICS 25.220.50 Compliance with a British Standard cannot confer im
4、munity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 28721-2 December
5、2015 ICS 25.220.50 Supersedes EN ISO 28721-2:2011English Version Vitreous and porcelain enamels - Glass-lined apparatus for process plants - Part 2: Designation and specification of resistance to chemical attack and thermal shock (ISO 28721-2:2015) maux vitrifis - Appareils maills pour les installat
6、ions industrielles - Partie 2: Dsignation et spcifications de la rsistance lattaque chimique et au choc (ISO 28721-2:2015) Emails und Emaillierungen - Emaillierte Apparate fr verfahrenstechnische Anlagen - Teil 2: Bezeichnung und Festlegung der chemischen und Temperaturschockbestndigkeit (ISO 28721-
7、2:2015)This European Standard was approved by CEN on 1 November 2015. 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 bibliographi
8、cal references concerning such 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
9、 of a CEN member into its own 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, Former Yugoslav Republic of
10、Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION
11、EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 28721-2:2015 EBS EN ISO 28721-2:2015EN ISO 28721-2:2015 (E) 3 European forewor
12、d This document (EN ISO 27821-2:2015) has been prepared by Technical Committee ISO/TC 107 “Metallic and other inorganic coatings“ in collaboration with Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which is held by BSI. This European Standard shall be give
13、n the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2016, and conflicting national standards shall be withdrawn at the latest by June 2016. Attention is drawn to the possibility that some of the elements of this document may be the
14、 subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 28721-2:2011. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to imp
15、lement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romani
16、a, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 28721-2:2015 has been approved by CEN as EN ISO 28721-2:2015 without any modification. BS EN ISO 28721-2:2015ISO 28721-2:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative referen
17、ces 13 Designation 14 Quality requirements 24.1 Rate of corrosion in hydrochloric acid . 24.2 Rate of corrosion in sodium hydroxide solution 24.3 Crack formation temperature 2Bibliography 3 ISO 2015 All rights reserved iiiContents PageBS EN ISO 28721-2:2015ISO 28721-2:2015(E)ForewordISO (the Interna
18、tional Organization 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 be
19、en established 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 stan
20、dardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accorda
21、nce with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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 rights. Details o
22、f any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorse
23、ment.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsib
24、le for this document is ISO/TC 107, Metallic and other inorganic coatings.This second edition of ISO 28721-2 cancels and replaces the first edition (ISO 28721-2:2008), of which it constitutes a minor revision.ISO 28721 consists of the following parts, under the general title Vitreous and porcelain e
25、namels Glass-lined apparatus for process plants: Part 1: Quality requirements for apparatus, components, appliances and accessories Part 2: Designation and specification of resistance to chemical attack and thermal shock Part 3: Thermal shock resistance Part 4: Quality requirements for glass-lined f
26、langed steel pipes and flanged steel fittings Part 5: Presentation and characterisation of defectsiv ISO 2015 All rights reservedBS EN ISO 28721-2:2015ISO 28721-2:2015(E)IntroductionFor many materials, the chemical composition can serve as a basis for a specification. This is not possible for chemic
27、al enamels because the composition is tied very closely to the specific enamelling technique and is therefore not disclosed by the manufacturer for competitive reasons. In order to ascribe measurable attributes to an enamel besides its general designation, the manufacturer conducts standardized test
28、s and specifies its enamel in terms of the resulting resistance to corrosion and thermal shock, together with a declaration of the structure of the cover coat enamel and the colour of the enamel.The quality requirements stated in this part of ISO 28721 represent the minimum requirements a chemical e
29、namel is expected to meet based on the current state of the art. ISO 2015 All rights reserved vBS EN ISO 28721-2:2015BS EN ISO 28721-2:2015Vitreous and porcelain enamels Glass-lined apparatus for process plants Part 2: Designation and specification of resistance to chemical attack and thermal shockW
30、ARNING This International Standard calls for the use of substances and/or procedures that may be injurious to health if adequate safety measures are not taken. This International Standard does not address any health hazards, safety or environmental matters associated with its use. It is the responsi
31、bility of the user of this International Standard to establish appropriate health, safety and environmentally acceptable practices and take suitable actions for any national and International regulations. Compliance with this International Standard does not of itself confer immunity from legal oblig
32、ations.1 ScopeThis part of ISO 28721 specifies requirements for the resistance to chemical attack and thermal shock of chemical enamels and their designation for ordering purposes.It is applicable to enamelled apparatus, piping and other components primarily used for process equipment in chemical pl
33、ants.It only applies to unalloyed and low-alloy carbon steels suitable for enamelling.NOTE The main criteria for assessing enamel quality are the resistance to chemical attack and thermal shock and the structure of the cover coat enamel.2 Normative referencesThe following documents, in whole or in p
34、art, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 13807, Vitreous and porcelain enamels Determi
35、nation of crack formation temperature in the thermal shock testing of enamels for the chemical industryISO 28706-2, 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
36、/or their vapoursISO 28706-4, Vitreous and porcelain enamels Determination of resistance to chemical corrosion Part 4: Determination of resistance to chemical corrosion by alkaline liquids using a cylindrical vessel3 DesignationThe enamel quality shall be designated by stating the following informat
37、ion: the rate of corrosion in hydrochloric acid, determined in accordance with ISO 28706-2; the rate of corrosion in sodium hydroxide solution, determined in accordance with ISO 28706-4; the crack formation temperature, determined in accordance with ISO 13807;INTERNATIONAL STANDARD ISO 28721-2:2015(
38、E) ISO 2015 All rights reserved 1BS EN ISO 28721-2:2015ISO 28721-2:2015(E) the structure of the cover coat enamel, e.g. all-vitreous, all-semicrystalline, vitreous on a semicrystalline intermediate layer and semicrystalline on a vitreous intermediate layer; the colour of the enamel.The designation o
39、f data on quality requirements in accordance with this part of ISO 28721 shall be as follows:Enamel quality requirements in accordance with ISO 28721-2.4 Quality requirements4.1 Rate of corrosion in hydrochloric acidWhen determined in accordance with ISO 28706-2, the resistance to condensing hydroch
40、loric acid vapour shall be equal to or less than 0,08 mm/year.4.2 Rate of corrosion in sodium hydroxide solutionWhen determined in accordance with ISO 28706-4, the rate of corrosion in sodium hydroxide solution shall be equal to or less than 0,40 mm/year.The ratio of the volume, in cubic centimetres
41、, of the attacking sodium hydroxide solution to the area, in square centimetres, of the exposed enamel surface shall be 3,5:1.4.3 Crack formation temperatureWhen determined in accordance with ISO 13807, the crack formation temperature shall be equal to or greater than 190 C.For enamels used on acces
42、sories such as agitators, baffles, thermometer wells, immersion tubes, intermediate rings, sensors and perforated plates, and also for piping accessories and pumps, a crack formation temperature of at least 170 C may be permissible.The crack formation temperature determined in accordance with ISO 13
43、807 represents a characteristic of the specimens tested. The test result shall not, therefore, be applied directly to an apparatus or accessories.Temperature limits for thermal shock and for heating and cooling of an apparatus are given in the thermal shock diagram and the heating/cooling diagram in
44、 ISO 28721-3.NOTE The drying oven temperature has a minimum of 210 C subtracting 20 C for the quenching water temperature.2 ISO 2015 All rights reservedBS EN ISO 28721-2:2015ISO 28721-2:2015(E)Bibliography1 ISO 28721-3, Vitreous and porcelain enamels Glass-lined apparatus for process plants Part 3:
45、Thermal shock resistance ISO 2015 All rights reserved 3This page deliberately left blankThis page deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related publications, information and services.BSI is incorporated by Royal Charter. Briti
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