ISO INTERNATIONAL STANDARD 28721-5 First edition 2016-02-15 Vitreous and porcelain enamels Glass-lined apparatus for process plants - Part 5: Presentation and characterization of defects Emaux vitrifiés - Appareils émailles pour les installations industrielles Partie 5: Présentation et caractérisation des défauts Reference number IS0 28721-5:2016(E) ISO International Organization for Standardization @ IS0 2016 ZHEJIANG INST OF STANDARDIZATION C1 5956617 IS0 28721-5:2016(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org Licensee-ZHEJIANG INST OF STANDARDIZAISQ 0d6 - All rights reserved HS und Not for Resale, 2016/4/26 02:11:56 networking permited without license from IHS IS0 28721-5:2016(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references 3 Terms and definitions 4 Enamelling defects ..2 4.1 Colour lines. .2 4.1.1 General 4.1.2 Strain lines 2 4.1.3 Tearings. ..3 4.1.4 Pearl lines. 4 4.1.5 Shore lines ..4 4.1.6 Drying cracks .5 4.2 Boiling defect ..6 4.2.1 Further designations. .6 4.2.2 Description. .6 4.2.3 Origin and causes 4.2.4 Classification .7 4.2.5 Suggestions for defect treatment 4.3 Rough enamel surface 7 4.3.1 Underfired areas 7 4.3.2 Eggshell. ..8 4.4 Dimple .9 4.4.1 Further designations .9 4.4.2 Description. .10 4.4.3 Origin and causes. ..10 4.4.4 Classification .10 4.4.5 Suggestions for defect treatment .10 4.5 Pinholes. .10 4.5.1 Further designations. .10 4.5.2 Description. ..10 4.5.3 Origin and causes .11 4.5.4 Classification ..11 4.5.5 Suggestions for defect treatment .11 4.6 Contamination. .11 4.6.1 Chamotte/refractory clay .11 4.6.2 Scale. 4.6.3 Ceramic fibres. ..13 4.7 Colour deviations. ..14 4.7.1 Water marks ..14 4.7.2 Colour stains .15 5 Repaired areas .16 5.1 Polished area .16 5.1.1 Further designations. ..16 5.1.2 Description. ..16 5.1.3 Origin and causes. ..17 5.1.4 Classification ..17 5.1.5 Suggestions for defect treatment. .17 5.2 Enamel-covered area after grinding. ..17 5.2.1 Further designations. ..17 5.2.2 Description. .17 5.2.3 Origin and causes. .18 5.2.4 Classification ..18 5.2.5 Suggestions for defect treatment! ..18 iii icensee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 ed without license from IHS Not for Resale, 2016/4/26 02:11:56