API RP 505-2018 Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I Zone 0 Zone 1 and Zone 2 (Second Edi.pdf

1、Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2API RECOMMENDED PRACTICE 505SECOND EDITION, AUGUST 2018Special NotesAPI publications necessarily address problems of a general nature. With respe

2、ct to particular circumstances, local,state, and federal laws and regulations should be reviewed.Neither API nor any of APIs employees, subcontractors, consultants, committees, or other assignees make anywarranty or representation, either express or implied, with respect to the accuracy, completenes

3、s, or usefulness of theinformation contained herein, or assume any liability or responsibility for any use, or the results of such use, of anyinformation or process disclosed in this publication. Neither API nor any of APIs employees, subcontractors,consultants, or other assignees represent that use

4、 of this publication would not infringe upon privately owned rights.API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure theaccuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, org

5、uarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss ordamage resulting from its use or for the violation of any authorities having jurisdiction with which this publication mayconflict.API publications are published to facilitate the br

6、oad availability of proven, sound engineering and operatingpractices. These publications are not intended to obviate the need for applying sound engineering judgmentregarding when and where these publications should be utilized. The formulation and publication of API publicationsis not intended in a

7、ny way to inhibit anyone from using any other practices.Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standardis solely responsible for complying with all the applicable requirements of that standard. API does not represent,warrant, or guarant

8、ee that such products do in fact conform to the applicable API standard.All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission

9、from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, NW, Washington, DC 20005.Copyright 2018 American Petroleum InstituteForewordNothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for themanufacture, sale, or

10、use of any method, apparatus, or product covered by letters patent. Neither should anythingcontained in the publication be construed as insuring anyone against liability for infringement of letters patent.The verbal forms used to express the provisions in this document are as follows.Shall: As used

11、in a standard, “shall” denotes a minimum requirement in order to conform to the standard.Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in orderto conform to the standard.May: As used in a standard, “may” denotes a course of action permissi

12、ble within the limits of a standard.Can: As used in a standard, “can” denotes a statement of possibility or capability.This document was produced under API standardization procedures that ensure appropriate notification andparticipation in the developmental process and is designated as an API standa

13、rd. Questions concerning theinterpretation of the content of this publication or comments and questions concerning the procedures under whichthis publication was developed should be directed in writing to the Director of Standards, American PetroleumInstitute, 1220 L Street, NW, Washington, DC 20005

14、. Requests for permission to reproduce or translate all or any partof the material published herein should also be addressed to the director.Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-timeextension of up to two years may be added to t

15、his review cycle. Status of the publication can be ascertained from theAPI Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is publishedannually by API, 1220 L Street, NW, Washington, DC 20005.Suggested revisions are invited and should be submitted to the S

16、tandards Department, API, 1220 L Street, NW,Washington, DC 20005, standardsapi.org.iiiContentsPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Purpose . . . . . . . . . . . .

17、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

18、Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19、 . . . . . . . . . 22.2 Industry Codes, Guides, and Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.3 Government Codes, Rules, and Regulations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20、. 43 Terms, Definitions, and Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.1 Terms and Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21、 . . 43.2 Acronyms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Basic Conditions for a Fire or Explosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

22、 . . . . . 135 Flammable and Combustible Liquids, Gases, and Vapors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23、. . 135.2 Flammable and Combustible Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135.3 Flammable Highly Volatile Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145.

24、4 Flammable Lighter-than-air Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145.5 National Electrical Code Grouping of Atmospheric Mixtures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Classification Criteria.

25、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.

26、2 Sources of Release (ANSI/ISA 60079-10-1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176.3 Zone Designation (ANSI/ISA 60079-10-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176.4 Extent of Zon

27、e (ANSI/ISA 60079-10-1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176.5 Classification Criteria and Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206.6 Ventilation . . . . . .

28、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256.7 Adjacent Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

29、6.8 Use of Combustible Gas Detection Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 Extent of a Classified Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337.1 General.

30、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337.2 Outdoor Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31、. . . . . 337.3 Enclosed Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 Recommendations for Determining Degree and Extent of Classified LocationsCommon Applications. . . . . . . . . . . . . . . . . . .

32、 . . . . . . . . . . . . . . . . . . . . . . . . 348.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348.2 Recommendations for Areas Surrounding Specific Equipment . . . . . . . . . . .

33、 . . . . . . . . . . . . . . . . . . . 359 Recommendations for Determining Degree and Extent of Classified Locations in Petroleum Refineries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529.1 Introduction. . . . . . . .

34、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5310 Recommen

35、dations for Determining Degree and Extent of Classified Locations at Drilling Rigs and Production Facilities on Land and on Marine Fixed Platforms. . . . . . . . . . . . . . . 5910.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36、. . . . . . . . . . . . . . . . . . . . . . 5910.2 Drilling Areas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6010.3 Production Facilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6110.4 Drilling Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62vContentsPage10.5 Producing Oil and Gas Wells. . . . . . . . .

38、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7110.6 Oil and Gas Processing and Storage Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7710.7 Automatic Custody Transfer (ACT) Units. . . . . . . . .

39、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8010.8 Produced/Processed Water Handling Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8010.9 Compressor or Pump Handling Flammable Liquids, Gases, or Vapors . . . . . . .

40、. . . . . . . . . . . . . . . . . 8110.10 Drip Pans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8410.11 Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

41、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8510.12 Sumps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8710.13 Drains . . . . . . . . . . . . . . . . . . . . . . . . . . .

42、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8910.14 Reserved For Future Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9410.15 Screwed Connections, Flanges, Valves,

43、and Valve Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9510.16 Control Panels Containing Instrumentation Utilizing or Measuring Flammable Liquids . . . . . . . . . . 9510.17 Gas Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9711 Recommendations for Determining Degree and Extent of Classified Locations on Mobile Offshore Drilling Units (MODUs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9711.1 General. . . . . . .

45、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9711.2 Definitions Specific To MODUs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9811.3 R

46、eserved For Future Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9911.4 Classified Locations on MODUs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9911

47、.5 Basis for Area Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10011.6 Classification of Hazardous (Classified) Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10111.7 Drill

48、 Floor and Derrick Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10311.8 Substructure or Moonpool Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10311.9 Mud

49、System Processing Equipment Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11011.10 Mud Tanks (After Discharge of Final Degasser). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11011.11 Mud Ditches or Troughs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11411.12 Mud Pumps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11411.13 Mud Proc