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 505FIRST EDITION, NOVEMBER 1997REAFFIRMED, AUGUST 2013Recommended Practice for Classification of Locations for Electrica
2、l Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2Manufacturing, Distribution and Marketing DepartmentAPI RECOMMENDED PRACTICE 505FIRST EDITION, NOVEMBER 1997REAFFIRMED, AUGUST 2013SPECIAL NOTESAPI publications necessarily address problems of a general nature.
3、With respect to partic-ular circumstances, local, state, and federal laws and regulations should be reviewed.API is not undertaking to meet the duties of employers, manufacturers, or suppliers towarn and properly train and equip their employees, and others exposed, concerning healthand safety risks
4、and precautions, nor undertaking their obligations under local, state, or fed-eral laws.Information concerning safety and health risks and proper precautions with respect to par-ticular materials and conditions should be obtained from the employer, the manufacturer orsupplier of that material, or th
5、e material safety data sheet.Nothing contained in any API publication is to be construed as granting any right, byimplication or otherwise, for the manufacture, sale, or use of any method, apparatus, or prod-uct covered by letters patent. Neither should anything contained in the publication be con-s
6、trued as insuring anyone against liability for infringement of letters patent.Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least everyfive years. Sometimes a one-time extension of up to two years will be added to this reviewcycle. This publication will no longer be
7、in effect five years after its publication date as anoperative API standard or, where an extension has been granted, upon republication. Statusof the publication can be ascertained from the API Manufacturing, Distribution and Market-ing Department telephone (202) 682-8000. A catalog of API publicati
8、ons and materials ispublished annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C.20005.This document was produced under API standardization procedures that ensure appropri-ate notification and participation in the developmental process and is designated as an APIstandard. Qu
9、estions concerning the interpretation of the content of this standard or com-ments and questions concerning the procedures under which this standard was developedshould be directed in writing to the director of the Manufacturing, Distribution and Market-ing Department, American Petroleum Institute,
10、1220 L Street, N.W., Washington, D.C.20005. Requests for permission to reproduce or translate all or any part of the material pub-lished herein should also be addressed to the director.API standards are published to facilitate the broad availability of proven, sound engineer-ing and operating practi
11、ces. These standards are not intended to obviate the need for apply-ing sound engineering judgment regarding when and where these standards should beutilized. The formulation and publication of API standards is not intended in any way toinhibit anyone from using any other practices.Any manufacturer
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14、.W., Washington, D.C. 20005.Copyright 1997 American Petroleum InstituteFOREWORDThis Recommended Practice is under the joint jurisdiction of the API Exploration andProduction (E it is anticipated that the 1999 NEC will also reference RP505 inArticle 505.API publications may be used by anyone desiring
15、 to do so. Every effort has been made bythe Institute to assure the accuracy and reliability of the data contained in them; however, theInstitute makes no representation, warranty, or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss
16、 or damage resultingfrom its use or for the violation of any federal, state or municipal regulation with which thispublication may conflict.Suggested revisions are invited and should be submitted to the director of the Manufactur-ing, Distribution and Marketing Department, American Petroleum Institu
17、te, 1220 L Street,N.W., Washington, D.C. 20005.iiiCONTENTSPage1 SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . 11.2 Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1 Industry Codes, Gu
19、ides and Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2 Government Codes, Rules, and Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 ACRONYMS AND ABBREVIATED DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . 43.1 Acronyms . . . . . .
20、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.2 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 BASIC CONDITIONS FOR A FIRE OR EXPLOSION. . . . . . . . . . . . . . . . .
21、 . . . . . . . 85 FLAMMABLE AND COMBUSTIBLE LIQUIDS, GASES, AND VAPORS . . . . . . 85.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85.2 Flammable and Combustible Liquids . . . . . . . . . . . . . . . . . . . . . . . . . .
22、 . . . . . . . 85.3 Flammable Highly Volatile Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.4 Flammable Lighter-Than-Air Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.5 National Electrical Code Grouping of Atmospheric Mixtures . . . .
23、 . . . . . . . . . . 96 CLASSIFICATION CRITERIA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106.2 Sources of Release (IEC 79-10, Mod) .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106.3 Zone Designation (IEC 79-10, Mod) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116.4 Extent of Zone (IEC 79-10, Mod) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116.5 National Electric
25、al Code Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.6 Ventilation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.7 Adjacent Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26、 . . . . . . . . . . . . . . . . . 186.8 Use of Combustible Gas Detection Equipment . . . . . . . . . . . . . . . . . . . . . . . . . 197 EXTENT OF A CLASSIFIED LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207.1 General . . . . . . . . . . . . . . . . . . . . . . . . . .
27、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207.2 Outdoor Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217.3 Enclosed Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
28、RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OFCLASSIFIED LOCATIONSCOMMON APPLICATIONS . . . . . . . . . . . . . . . . . . 218.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218.2 Recommendations for Areas Surrounding Sp
29、ecific Equipment . . . . . . . . . . . . 219 RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OFCLASSIFIED LOCATIONS IN PETROLEUM REFINERIES . . . . . . . . . . . . . . . . . 369.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30、369.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3610 RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OFCLASSIFIED LOCATIONS AT DRILLING RIGS AND PRODUCTIONFACILITIES ON LAND AND ON MARINE FIXED PLATFORMS. . . . . . . . . . . . 44v
31、Page10.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4410.2 Drilling Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4410.3 Production Facilities . . . . . . . . .
32、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4410.4 Drilling Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4410.5 Producing Oil and Gas Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33、 . . . . . 5110.6 Oil and Gas Processing and Storage Equipment . . . . . . . . . . . . . . . . . . . . . . . . 5610.7 Automatic Custody Transfer (ACT) Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5710.8 Flammable Gas-Blanketed Equipment and Produced/Processed WaterHandling Equipmen
34、t. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5810.9 Compressor or Pump Handling Flammable Liquids, Gases, or Vapors . . . . . . 5810.10 Drip Pans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、 . 5910.11 Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5910.12 Sumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6210.13 Drains . . . . . . . . . . . . . .
36、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6310.14 Reserved for Future Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6510.15 Screwed Connections, Flanges, Valves, and Valve Operators . . . . . . . . . . . . . . 651
37、0.16 Control Panels Containing Instrumentation Utilizing or MeasuringFlammable Liquids, Gases, or Vapors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6611 RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OFCLASSIFIED LOCATIONS ON MOBILE OFFSHORE DRILLING UNITS(MODUS) . . . . . .
38、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6711.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6711.2 Definitions Specific to MODUS. . . . . . . . . . . . . . . .
39、 . . . . . . . . . . . . . . . . . . . . . 6811.3 Reserved for Future Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6811.4 Classified Locations on Mobile Offshore Drilling Units (MODUS) . . . . . . . . 6811.5 Basis for Area Classification . . . . . . . . .
40、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6911.6 Classification of Hazardous (Classified) Locations . . . . . . . . . . . . . . . . . . . . . . 7011.7 Drill Floor and Derrick Areas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7111.8 Substructure or M
41、oonpool Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7111.9 Mud System Processing Equipment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 7811.10 Mud Tanks (After Discharge of Final Degasser) . . . . . . . . . . . . . . . . . . . . . . . . 7811.11 Mud Di
42、tches or Troughs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8011.12 Mud Pumps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8011.13 Mud Processing Equipment (Between the Bell Nipple and Mud Discharge
43、of Final Degasser). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8211.14 Desander or Desilter (Between Mud Discharge of Final Degasser andthe Mud Pit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44、. . 8211.15 Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8311.16 Diverter Line Outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8411.17 Blowout Preventer (BOP). . . . . . .
45、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8411.18 Well Test Equipment Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8411.19 Rooms Used to Store Paint (Paint Lockers). . . . . . . . . . . . . . . . . . . . . . . . . . . . 8411.20 Bat
46、tery Rooms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8411.21 Reserved for Future Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8411.22 Helicopter Fuel Storage Areas . . . . . . . . . . . . . . . . .
47、. . . . . . . . . . . . . . . . . . . . . 8411.23 Classification of Adjacent Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8412 RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OFCLASSIFIED LOCATIONS AT DRILLING RIGS AND PRODUCTIONFACILITIES ON FLOATING PRODUCTION UNI
48、TS . . . . . . . . . . . . . . . . . . . . . . . 8512.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85viPage12.2 Floating Production Storage and Offloading Units (FPSOS) . . . . . . . . . . . . . . 8512.3 Tension Leg Platfor
49、ms (TLPS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8512.4 Spars, Caissons, and Similar Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8512.5 Classification of Adjacent Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8513 RESERVED FOR FUTURE USE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8914 RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OFCLASSIFIED LOCATIONS AT PETROLEUM PIPELINETRANSPORTATION FACILITIES. . . . . . . . . . . . . . . . . . . . . . . . . . . .
