1、 AMERICAN NATIONAL STANDARD ANSI/ISA-60079-31 (12.10.03)-2015 Supersedes ANSI/ISA-60079-31 (12.10.03)-2013 Explosive Atmospheres Part 31: Equipment Dust Ignition Protection by Enclosure “t” (Edition 2) Approved 12 June 2015 ANSI/ISA-60079-31 (12.10.03)-2015 Explosive atmospheres - Part 31: Equipment
2、 dust ignition protection by enclosure “t“ ISBN: 978-1-941546-54-3 Copyright 2015 by IEC, ANSI, and ISA. All rights reserved. Not for resale. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any mea
3、ns (electronic mechanical, photocopying, recording, or otherwise), without the prior written permission of the Publisher. ISA 67 Alexander Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 ISA - The International Society of Automation ANSI/ISA-60079-31 Second Edition Underwriters Lab
4、oratories Inc. ANSI/UL 60079-31 Second Edition Explosive Atmospheres - Part 31: Equipment Dust Ignition Protection by Enclosure “t” June 12, 2015 ANSI/UL 60079-31-2015 This page intentionally left blank. Commitment for Amendments This standard is issued jointly by the International Society of Automa
5、tion (ISA) and Underwriters Laboratories Incorporated (UL). Comments or proposals for revisions on any part of the standard may be submitted to UL at any time. Revisions to this standard will be made only after processing according to the standards development procedures of UL. ISA and UL will issue
6、 revisions to this standard by means of a new edition or revised or additional pages bearing their date of issue. ISBN 978-1-941546-54-3 Copyright 2015 ISA These materials are subject to copyright claims of IEC, ANSI and ISA. All rights reserved. Not for resale. Printed in the United States of Ameri
7、ca. No part of this publication may be reproduced in any form, including an electronic retrieval system, without the prior written permission of ISA. All requests pertaining to this Standard should be submitted to ISA. The most recent designation of ANSI/ISA 60079-31 as an American National Standard
8、 (ANSI) occurred on June 12, 2015. Copyright 2015 Underwriters Laboratories Inc. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards
9、 shall remain the sole and exclusive property of UL. This ANSI/UL Standard for Safety consists of the Second Edition. The most recent designation of ANSI/UL 60079-31 as an American National Standard (ANSI) occurred on June 12, 2015. ANSI approval for a standard does not include the Cover Page, Trans
10、mittal Pages, Title Page (front and back), or the Preface. The National Difference Page and IEC Foreword are also excluded from the ANSI approval of IEC-based standards. Any other portions of this ANSI/UL standard that were not processed in accordance with ANSI/UL requirements are noted at the begin
11、ning of the impacted sections. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. To purchase UL Standards, visit Comm 200
12、0 at http:/m- or call toll-free 1-888-853-3503.This page intentionally left blank. 7 ANSI/ISA-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 CONTENTS Summary of Topics 9 General Notes 11 National Differences 15 FOREWORD . 17 1 Scope 21 2 Normative references . 21 3 Terms and definitions . 22 4 Ge
13、neral . 22 4.1 Levels of protection . 22 4.2 Equipment groups and ingress protection 22 4.3 Requirements for electrical equipment with level of protection “ta” 23 4.4 Requirements for electrical equipment with Level of Protection “tb” and “tc” . 25 5 Construction 25 5.1 Joints . 25 5.2 Cable glands
14、. 26 5.3 Entries . 27 6 Verification and tests 27 6.1 Type tests 27 6.2 Routine tests . 29 7 Marking . 29 Bibliography . 30 This page intentionally left blank. 9 ANSI/ISA-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 UL Standard for Safety for Explosive Atmospheres - Part 31: Equipment Dust Igni
15、tion Protection by Enclosure “t” UL 60079-31 Second Edition Dated June 12, 2015 Summary of Topics Adoption of IEC 60079-31, Explosive Atmospheres - Part 31: Equipment Dust Ignition Protection by Enclosure “t” (second edition issued November 2013) as a new IEC-based UL standard, UL 60079-31 (IEC 6007
16、9-31:2013), with US National Differences. Although this is the first-time publication of this Standard by UL and ISA, it is being published as the Second edition in order to align ULs and ISAs edition numbers with that of the IEC Standard. As a result, one or more UL edition numbers have been skippe
17、d to match that of the IEC edition number. The new revised requirements are substantially in accordance with Proposal(s) on this subject dated January 23, 2015 and April 3, 2015. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any f
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21、st any loss, expense, liability, damage, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. 10 ANSI/ISA-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 The re
22、quirements in this Standard are now in effect, except for those paragraphs, sections, tables, figures, and/or other elements of the Standard having future effective dates as indicated in the preface. The prior text for requirements that have been revised and that have a future effective date are loc
23、ated after the Standard, and are preceded by a “SUPERSEDED REQUIREMENTS“ notice. 11 ANSI/ISA-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 General Notes This UL Standard is based on IEC Publication 60079-31: second edition Explosive Atmospheres - Part 31: Equipment Dust Ignition Protection by En
24、closure “t”. IEC publication 60079-31 is copyrighted by the IEC. Efforts have been made to synchronize the UL edition number with that of the corresponding IEC standard with which this standard is harmonized. As a result, one or more UL edition numbers have been skipped to match that of the IEC edit
25、ion number. Note - Although the intended primary application of this Standard is stated in its Scope, it is important to note that it remains the responsibility of the users of the Standard to judge its suitability for their particular purpose. UL Effective Date The effective date for UL 60079-31 (I
26、EC 60079-31:2013), Second edition is June 12, 2015. A UL effective date is one established by Underwriters Laboratories Inc. and is not part of the ANSI approved standard. The following people served as members of the STP 60079 and participated in the review of this document: NAME COMPANY T. Schnaar
27、e, Chair Rosemount Inc T. Adam Ametek Drexelbrook R. Allen Honeywell Inc D. Ankele UL LLC R. Baran Koehler Bright Star LLC S. Bihler Atec Training any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and nongovernmental
28、 organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on techn
29、ical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IE
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31、mity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) I
32、EC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure
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34、 nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the refer
35、enced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. 18 ANS
36、I/ISA-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 International Standard IEC 60079-31 has been prepared by IEC technical committee 31: Equipment for explosive atmospheres. This second edition cancels and replaces the first edition published in 2008. This edition constitutes a technical revisio
37、n. The significance of changes between IEC 60079-31, Edition 2.0 (2012) and IEC 60079-31, Edition 1.0 (2008) (including Corrigendum) is as listed below: Type Changes Clause Minor and editorial changes Extension Major technical changes Document has been restructured from the first edition Numerous X
38、The marked maximum surface temperature shall be measured on the external surfaces of the enclosure and the surfaces of the internal components for equipment with types of protection “ta” 4.3.2 C1 Additional protection for arcing and sparking parts for “ta” 4.3.6 C2 Limiting the internal pressure tes
39、t to enclosures where the seal is not physically constrained from moving. 4.4.2 X Requirements for tapered threaded joints without an additional seal or gasket added. 5.1.2 X Requirements for cable gland aligned for all levels and Groups the only difference is now the required IP protection 5.2 X Re
40、quirements for plain entries added 5.3.1 X 5 threads for parallel threads only required when no seal is used 5.3.2 X Test for internal enclosure for level “ta” added. 6.1.1.2 C3 Eliminating of the “fault” table and reduction of the dust layer depth for the thermal test for type of protection “ta”. 6
41、.1.2 X NOTE The technical changes referred to include the significance of technical changes in the revised IEC Standard, but they do not form an exhaustive list of all modifications from the previous version. More guidance may be found by referring to the Redline Version of the standard. 19 ANSI/ISA
42、-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 Explanations: A) Definitions Minor and editorial changes clarification decrease of technical requirements minor technical change editorial corrections These are changes which modify requirements in an editorial or a minor technical way. They include
43、 changes of the wording to clarify technical requirements without any technical change, or a reduction in level of existing requirement. Extension addition of technical options These are changes which add new or modify existing technical requirements, in a way that new options are given, but without
44、 increasing requirements for equipment that was fully compliant with the previous standard. Therefore, these will not have to be considered for products in conformity with the preceding edition. Major technical changes addition of technical requirements increase of technical requirements These are c
45、hanges to technical requirements (addition, increase of the level or removal) made in a way that a product in conformity with the preceding edition will not always be able to fulfil the requirements given in the later edition. These changes have to be considered for products in conformity with the p
46、receding edition. For these changes additional information is provided in clause B) below. NOTE These changes represent current technological knowledge. However, these changes should not normally have an influence on equipment already placed on the market. B) Information about the background of Majo
47、r Technical Changes C1 - A requirement was added for “ta” to require the temperature marking to be based on the highest of either the temperature produced by the internal components or the external surface temperature. C2 - Requirements were added for “ta” equipment that contains a normally arcing p
48、art to require a supplementary internal enclosure around the arcing part. C3 - Requires an impact test on the supplementary enclosure for “ta” equipment. The text of this standard is based on the following documents: 20 ANSI/ISA-60079-31 (12.10.03) ANSI/UL 60079-31 12 June 2015 FDIS Report on voting
49、 31/1079/FDIS 31/1094/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. This International Standard is to be used in conjunction with IEC 60079-0. A list of all parts of the IEC 60079 series, under the general title Explosive atmospheres, can be found on the IEC website. The committee has decided that the contents of this p
