1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 28721-2:2011Vitreous and porcelain enamels Glass-lined apparatus for process plantsPart 2: Designation and specification of resistance to chemical attack and thermal sh
2、ock (ISO 28721-2:2008)Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 28721-2:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN
3、 ISO 28721-2:2011. It is identical to ISO 28721-2:2008. It supersedes BS EN 15159-2:2006, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e S T I / 3 6 , V i t r e o u s e n a m e l c o a t i n g s .A list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
4、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 0 580 72282 0 ICS 25.220.50; 71.120.10 Compliance with a British Standard cannot co
5、nfer 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 d Copyright European Committee for Standardization Provided by IHS under license
6、with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 28721-2 April 2011 ICS 25.220.50 Supersedes EN 15159-2:2006English Version Vitreous and porcelain enamels - Glass-lined apparatus for process plants - P
7、art 2: Designation and specification of resistance to chemical attack and thermal shock (ISO 28721-2:2008) maux vitrifis - Appareils maills pour les installations industrielles - Partie 2: Dsignation et spcifications de la rsistance lattaque chimique et au choc thermique (ISO 28721-2:2008) Emails un
8、d Emaillierungen - Emaillierte Apparate fr verfahrenstechnische Anlagen - Teil 2: Bezeichnung und Festlegung der chemischen und Temperaturschockbestndigkeit (ISO 28721-2:2008) This European Standard was approved by CEN on 17 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal R
9、egulations 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 national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN m
10、ember. 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 language and notified to the CEN-CENELEC Management Centre has the same status as the official versions
11、. 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, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Sloven
12、ia, 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 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nat
13、ional Members. Ref. No. EN ISO 28721-2:2011: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 28721-2:2011 EN ISO 28721-2:2011 (E) 3 Foreword The text of ISO 28721-2:20
14、08 has been prepared by Technical Committee ISO/TC 107 “Metallic and other inorganic coatings” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 28721-2:2011 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which
15、 is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 2011. Attention is drawn to the possib
16、ility that some of the elements of this document may be the 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 15159-2:2006. According to the CEN/CENELEC Internal Regulations, the national standards or
17、ganizations of the following countries are bound to implement this European 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,
18、Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 28721-2:2008 has been approved by CEN as a EN ISO 28721-2:2011 without any modification. Copyright European Committee for Standardization Provided by IHS under license with CE
19、NNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 28721-2:2011ISO 28721-2:2008(E) ISO 2008 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies).
20、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 established has the right to be represented on that committee. International organizations, governmental and non-g
21、overnmental, 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2
22、. 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. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a
23、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 rights. ISO 28721-2 was prepared by the European Committee for Standardization (CEN) (as EN 15159-2) an
24、d 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. ISO 28721 consists of the following parts, under the general title Vitreous and porcelain enamels Glass-lined appar
25、atus 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 Copyright European Committee for Standardization Provided by IHS under
26、 license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 28721-2:2011ISO 28721-2:2008(E) iv ISO 2008 All rights reservedIntroduction For many materials, the chemical composition can serve as a basis for a specification. This is not possible for ch
27、emical 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
28、tests 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 chemi
29、cal enamel is expected to meet based on the current state of the art. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 28721-2:2011INTERNATIONAL STANDARD ISO 28721-2:200
30、8(E) ISO 2008 All rights reserved 1Vitreous and porcelain enamels Glass-lined apparatus for process plants Part 2: Designation and specification of resistance to chemical attack and thermal shock 1 Scope This part of ISO 28721 specifies requirements for the resistance to chemical attack and thermal
31、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 plants. It only applies to unalloyed and low-alloy carbon steels suitable for enamelling. NOTE The main criteri
32、a for assessing enamel quality are the resistance to chemical attack and thermal shock and the structure of the cover coat enamel. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. F
33、or undated references, the latest edition of the referenced document (including any amendments) applies. ISO 13807, Vitreous and porcelain enamels Determination of crack formation temperature in the thermal shock testing of enamels for the chemical industry ISO 28706-2, Vitreous and porcelain enamel
34、s 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 28706-4, Vitreous and porcelain enamels Determination of resistance to chemical corrosion Part 4: Determination of resistan
35、ce to chemical corrosion by alkaline liquids using a cylindrical vessel 3 Designation The enamel quality shall be designated by stating the following information: the rate of corrosion in hydrochloric acid, determined in accordance with ISO 28706-2; the rate of corrosion in sodium hydroxide solution
36、, determined in accordance with ISO 28706-4; the crack formation temperature, determined in accordance with ISO 13807; Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2
37、8721-2:2011ISO 28721-2:2008(E) 2 ISO 2008 All rights reserved 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 of data on qu
38、ality requirements in accordance with this part of ISO 28721 shall be as follows: Enamel quality requirements in accordance with ISO 28721-2. 4 Quality requirements 4.1 Rate of corrosion in hydrochloric acid When determined in accordance with ISO 28706-2, the resistance to condensing hydrochloric ac
39、id vapour shall be equal to or less than 0,08 mm/year. 4.2 Rate of corrosion in sodium hydroxide solution When 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, of
40、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 temperature When determined in accordance with ISO 13807, the crack formation temperature shall be equal to or greater than 190 C. For enamels used on accesso
41、ries 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 138
42、07 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
43、 ISO 28721-3. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 28721-2:2011ISO 28721-2:2008(E) ISO 2008 All rights reserved 3Bibliography 1 ISO 28721-3, Vitreous and por
44、celain enamels Glass-lined apparatus for process plants Part 3: Thermal shock resistance Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-This page deliberately left blankCopyrigh
45、t European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-This page deliberately left blankCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo r
46、eproduction or networking permitted without license from IHS-,-,-BSI is the independent national body responsible for preparing British Standardsand other standards-related publications, information and services. It presents the UK view on standards in Europe and at the international level. It is in
47、corporated by Royal Charter.British Standards Institution (BSI)raising standards worldwideBSI Group Headquarters389 Chiswick High Road London W4 4AL UKTel +44 (0)20 8996 9001Fax +44 (0)20 8996 Standards are updated by amendment or revision. Users of British Stan-dards should make sure that they pos
48、sess the latest amendments or editions.It is the constant aim of BSI to improve the quality of our products and serv-ices. We would be grateful if anyone finding an inaccuracy or ambiguity whileusing this British Standard would inform the Secretary of the technical com-mittee responsible, the identity of which can be found on the inside frontcover.Tel: +44 (0)20 8996 9001 Fax: +44 (0)20 8996 7001BSI offers Members an individual updating
