API RP 502, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone O, Zone 1, and Zone 2

145 Pages·2003·9.13 MB·English

by  American Petrolium Engineering

Date of Issue: August 17, 1998
Affected Publication: API Recommended Practice 505, Recommended Practice for
Classification of Locations for Electrical Installations at Petroleum Facilities Classified as
Class I, Zune O, Zune I, and Zone 2, Ist Edition, November 1997
ERRATA
The followingfigures are replaced by the next three pages:
Page 86, Figure 90
Page 87, Figure 91 and
Page 88, Figure 92.
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STD-APIIPETRO RP 505-ENGL 1777 m 0732290 üb07348 258
Vent outlet for free flow of high velocity
vapor mixtures. Vent outlet for passage of
large amount of vapor. Air or inert gas
mixtures during cargo loading, and ballasting
or during discharge. Also for vent outlet for
cargo pressurehacuum valve.
-- || ||| ||||| || ||| || |||| | || | | ||| | || | || |---
immediately above,
room (Note 3)
below, or next
to a cargo tank
00000
Zone0 Zone 1
00000
I I
Zone2 Non Hazardous
Notes:
1 This area dassified due to proximity to cargo tanks.
2. Areas more than 3m(lV) above the weatherdeck are unclassified except as required by this document for production
equipment contained therein.
3. Space must be:
a) continuously ventilated at 2 20 air changes per hour, and
b) loss of ventilation must be alarmed in a manned space, and
c) combustible gas detection must be installed in accordance with section 6.5.2 .
or, If ventilated e20 air changes per hour, loss of ventilation is not alarmed, or
gas detectors are not installed, then the area is classified Zone O.
4. An area 1 meter (3 feet) around vent is classified Zone O.
5. All spaces are subject to the adjacent space requirements of section 12.5.
6. Cargo is defined as a flammable gas or vapor or flammable or combustible liquid with a flashpoint below 6Ot(14O0F)
Figure 90-Typical Floating Production Storage and Off loading Unit (FPSO)
(See Section 12.2.1)
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STDSAPIIPETRO RP 505-ENGL 1447 W 0732290 Ob09347 174 W
below or next to
a cargo tank.
(Note 5)
00000
Zone0 Zone 1
-- || ||| ||||| || ||| || |||| | || | | ||| | || | || |--- 231N... otecasbAaeTS):))xnhr p etdiaesa cnd salcceodr oroi msleeclnmisodanot ibn ogntrcoeutfu la ea vstotiqhhsnetuiuasebinsniin lptlfeoygii lem3 a ug pvdmttaeeris doosnni(d unctldt Oeeei cmleas o o)ttstu onefae i sntctbdpahtgt o riiabeon oveet neax eq ida2rm mute lht2aiahupietr0 esymma w tr Ztar eoebeeeioiren dn ac cnc t .taii lo hehnnarreags 2s arntosn admai gfetlilateeeacunsddknrk a pnZiasnlee og.r ardena hc essuco p nfo1uuacrr eicl,dfa e:laae s,nns dadic ñpn eerd widm ietehx mcseeopcvtte iaoNrs nwo r6niet.h q5H .uaa2ilzr l .efa ldard mboymu tsha ibsl ed oliqcuumid eonr tg foars pvreondtsu ction
or, If ventilated e20 air changes per hour, loss of ventilation is not alarmed, or
gas detectors are not installed, then the area is classified Zone O.
4. All spaces are subject to the adjacent space requirements of section 12.5.
5. Cargo is defined as a flammable gas or vapor or flammable or combustible liquid with a flashpoint below 6OoC(14O0F)
Figure 91-Typical Tension Leg Pla?form (TLP)
(See Section 12.3.1)
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I
(Note 2)
+
3m(10')
U
L I II Il
A I
(Note 2)
(Note 3)( Note 6) -- || ||| ||||| || ||| || |||| | || | | ||| | || | || |---
00D00
Zone O Zone 1
zone* Non Hazardous
Notes:
1. This area classified due to proximity to cargo tanks.
2. Areas more than 3m(l O') above the weatherdeck are undassified except as required by this document for production
and drilling equipment contained therein.
3. Space containing processing equipment or natural gas fueled prime mover with all flammable liquid or gas vents
extended to the outside of the area are classified Zone 1 if:
a) continuously ventilated at 2 20 air changes per hour, and
b) loss of ventilation must be alarmed in a manned space, and
c) combustible gas detedion must be installed in accordance with section 6.5.2 .
or, If ventilated e20 air changes per hour, loss of ventilation is not alarmed, or
gas detedon are not installed, then the area is classified Zone O.
4. Moonpool area is unclassified if it contains all welded closed piping or continuous metallic tubing systems without
valves flanges or similar devices, and is not within the hazardous area created by adjacent equipment.
5. All spaces are subject to the adjacent space requirements of section 12.5.
6. Cargo is defined as a flammable gas or vapor or flammable or combustible liquid with a flashpoint below 60°C(1400F)
Figure 92-Typical Spar, Caisson, or Similar Unit
(See Section 12.4.1)
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m
STD.API/PETRO RP 505-ENGL 1777 0732270 Ob00578 b31
Recommended Practice for
Classification of Locations for
Electrical Installations at
Petroleum Facilities Classified as
Class I, Zone O, Zone 1, and Zone 2
AFIPRI SRTE ECDOIMTIMOENN, NDOEVDE PMRBAECRT I1C9E9 75 05 -- || ||| ||||| || ||| || |||| | || | | ||| | || | || |---
American
Petroleum
Strategies for Today’s
Institute
Environmental Partnwsbip
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~~~~ ~
STD.API/PETRO RP SOS-ENGL 1777 O732270 Ob00579 578 W
*b-
Strategies br Today4
Environmental Partnership
One of the most significant long-term trends affecting the future vitality of the petro-
leum industry is the public’s concerns about the environment. Recognizing this trend, API
member companies have developed a positive, forward looking strategy called STEP:
Strategies for Today’s Environmental Partnership: This program aims to address public
concerns by improving industry’s environmental, health and safety performance; docu-
menting performance improvements; and communicating them to the public. The founda-
tion of STEP is the API Environmental, Health and Safety Mission and Guiding
Principles. API standards, by promoting the use of sound engineering and operational
practices, are an important means of implementing API’s STEP program.
API ENVIRONMENTAL, HEALTH AND SAFETY MISSION
AND GUIDING PRINCIPLES
The members of the American Petroleum Institute are dedicated to continuous efforts to
improve the compatibility of our operations with the environment while economically
developing energy resources and supplying high quality products and services to consum-
ers. We recognize our responsibility to work with the public, the government, and others to
develop and to use natural resources in an environmentally sound manner while protecting
the health and safety of our employees and the public. To meet these responsibilities, API
members pledge to manage our businesses according to the following principles using
sound science to prioritize risks and to implement cost-effective management practices:
To recognize and to respond to community concerns about our raw materials, prod-
ucts and operations.
To operate our plants and facilities, and to handle our raw materials and products in a
manner that protects the environment, and the safety and health of our employees
and the public.
To make safety, health and environmental considerations a priority in our planning,
and our development of new products and processes.
To advise promptly, appropriate officials, employees, customers and the public of
information on significant industry-related safety, health and environmental hazards,
and to recommend protective measures.
To counsel customers, transporters and others in the safe use, transportation and dis-
posal of our raw materials, products and waste materials.
To economically develop and produce natural resources and to conserve those
resources by using energy efficiently.
To extend knowledge by conducting or supporting research on the safety, health and
environmental effects of our raw materials, products, processes and waste materials.
To commit to reduce overall emissions and waste generation.
To work with others to resolve problems created by handling and disposal of hazard-
ous substances from our operations.
To participate with government and others in creating responsible laws, regulations
and standards to safeguard the community, workplace and environment.
To promote these principles and practices by sharing experiences and offering assis-
tance to others who produce, handle, use, transport or dispose of similar raw materi-
als, petroleum products and wastes.
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m m
STD.API/PETRO RP 505-ENGL 1997 0732290 Ob00580 27T
Recommended Practice for
CECMPExaeplllneaaluotfcrsrsaaocttssitoruli nreiIfic an,iung caZd,m Da lPoi srIto tnnirFdiobeusaucn ttticOioao onni,l la DflZin aetdLpoit eaMiornoatsmrcekn eCea nts1itnlt agi,ao Dasten nspasidrft mfi eZoendrot naes 2 -- || ||| ||||| || ||| || |||| | || | | ||| | || | || |---
API RECOMMENDED PRACTICE 505
FIRST EDITION, NOVEMBER 1997
American
Petroleum
Institute
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STD.API/PETRO RP 505-ENGL 1777 9 0732270 Ob0058L L2b
SPECIAL NOTES
API publications necessarily address problems of a general nature. 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 to
warn and properly train and equip their employees, and others exposed, concerning health
and safety risks 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 or
supplier of that material, or the material safety data sheet.
-- || ||| ||||| || ||| || |||| | || | | ||| | || | || |--- ipiuscofonmityfcupvr gtcNubGepte hlrceDl leoyeiaeiods.cnteet v hhpiTaaapeveeitusrrahnierd saboriei gA. lntsln dalm iPS sy cn cpoubIo,aeonurA yr mtn nubiois Pntotaltlte aiageIh[nltci tlnti e sneyaactmdtreletna awaeiardenyonsrpnsi don dihsdb pan n aeeo woa eru, ontr adafi ep,anelon ssnldwg ec yr(atana- 2e. thr ttihoA0reieNentm e 2drarPsle ee)o imteIi qn vnl t6 aieuheapig8anexdnaeube2 wtrr uebfrie-t rx lfe8selnbioaidhtrt0cseecmyl o0ia aynt oiufu0tn nstoinblrh]dio drey o.eoe n r, Ainfa f en sAAf ina vhfeuscPPyrliac paeisttIIstn toeh, , ta fM godboi il1nvebre, oa 2t gmreeeugwne2 ns cyeauc0oo eonfegoff fLona aytrniA fcaortre s asmtnSfaPatu i rtrnatnlIeuresre fyeied dpettn wdeet,d,muge o rtu ibi,r, alnre i psDllN st t iw osph bcti.h nWgaaosiepte t rttdhurrie aa.oi,e,dpbn nd bapnrulWttduapi.uisbc enwtp bailaadgoialnntsc i irnthd caaoaoa iaa ntnttn miunt yto lgihddse oanti,ar aostn Moietbs gn.errrt eSh,e iape aavDttrcvrs,laki o.ose eteba dnurCwiytnys--s-.
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 API
standard. Questions concerning the interpretation of the content of this standard or com-
ments and questions concerning the procedures under which this standard was developed
should be directed in writing to the director of the Manufacturing, Distribution and Market-
ing Department, American Petroleum Institute, 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 practices. These standards are not intended to obviate the need for apply-
ing sound engineering judgment regarding when and where these standards should be
utilized. The formulation and publication of API standards is not intended in any way to
inhibit anyone from using any other practices.
Any manufacturer marking equipment or materials in conformance with the marking
requirements of an API standard is solely responsible for complying with all the applicable
requirements of that standard. API does not represent, warrant, or guarantee that such prod-
ucts do in fact conform to the applicable API standard.
All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or
transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise,
without prior writtenp ermissionf rom the publishel: Contact the Publishel;
API Publishing Services, 1220 L Street, N.W, Washington, D.C. 20005.
Copyright O 1997 American Petroleum Institute
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STD-APIIPETRO RP 505-ENGL 1797 m 0732290 Ob00582 Ob2
FOREWORD
This Recommended Practice is under the joint jurisdiction of the API Exploration and
Production (E&P) Department Committee on Production Equipment Standards, the API
Manufacturing Distribution and Marketing (MDM) Department, Committee on Refinery
Equipment, and the Pipeline Operations Technical Committee. It is based upon a level of
knowledge gained through experience and through the successful application of this practice
in the refining, drilling and producing, and pipeline segments of the petroleum industry.
Recommended Practice 505 was prepared as a supplement to the 1996 Edition of the
National Electrical Code (NEC) Article 505, with a scope limited to those petroleum facility
locations classified as Class I, Zone O, Zone 1, and Zone 2. Efforts were coordinated with the
work of the ISA SP12 committee,, which concurrently normalized the International Electro-
technical Commission (IEC) Standard 79-10 that addresses the zone area classification
scheme in general. RP 505 will serve the petroleum industry, essentially as an supplement to
both ISA 12.24.01 (IEC 79-10 Mod) and NEC Article 505. RP 500 is presently referenced
by Article 500 of the NEC;i t is anticipated that the 1999 NEC will also reference RP505 in
Article 505.
API publications may be used by anyone desiring to do so. Every effort has been made by
the Institute to assure the accuracy and reliability of thedata contained in them; however, the
Institute makes no representation, warranty, or guarantee in connection with this publication
and hereby expressly disclaims any liability or responsibility for loss or damage resulting
from its use or for the violation of any federal, state or municipal regulation with which this
publication may conflict.
Suggested revisions are invited and should be submitted to the director of the Manufactur-
ing, Distribution and Marketing Department, American Petroleum Institute, 1220 L Street,
N.W., Washington, D.C. 20005.
iii
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STD.API/PETRO RP 505-ENGL 1997 D 0732290 0b005t33 TTq D
CONTENTS
w3e
1 SCOPE ............................................................... 1
1.1 Purpose ......................................................... 1
...........................................................
1.2 scope 1
2 REFERENCES ........................................................ 2
2.1 Industry Codes. Guides and Standards. ................................ 2
............................
2.2 Government Codes. Rules. and Regulations 3
3 ACRONYMS AND ABBREVIATED DEFIMTIONS ........................ 4
3.1 Acronyms ....................................................... 4
3.2 Definitions. ...................................................... 4
4 BASIC CONDITIONS FOR A FIRE OR EXPLOSION. ....................... 8
5 FLAMMABLE AND COMBUSTIBLE LIQUIDS. GASES. AND VAPORS ...... 8
6 5556C55666.........L142351342 A SSFGFNFGEZSIllloxoeaeFaaautnntnmmmIeireeCeoncmmm rrnDAtaea aaoaalsleT l fbbb o .s .EIlllif.Z.Oeeeg l..R eo HLnaN..cnnea.i.it egdCltgr..ei i hh.o(R.caCIt.ln.asEeyIo.el. Tr( Cm.V C-.(EET.. Eboo7.R.Chlud9..CaaIse.- .7tAn t1 i. .7G9il-.0b .e.A9-..r. l1.L. oe1Mi...0ri L0u... qG,o,.p .i. Muq.da.i.Minu.s.)d.og e..i.sod.ds. . o..d.) s..f. ...). ... .A................t......m.................o..........s.........p..........h.........e.........r.........i....c........ ...M....................i..x............t.....u..........r........e.........s........ ............................................................................................................... . . ...11111889990 1010 -- || ||| ||||| || ||| || |||| | || | | ||| | || | || |---
6.5 National Electrical Code Criteria .................................... 12
6.6 Ventilation ...................................................... 16
6.7 AdjacentAreas .................................................. 18
6.8 Use of Combustible Gas Detection Equipment ......................... 19
EXTENT OF A CLASSIFIED LOCATION ................................ 20
7.1 General ........................................................ 20
7.2 Outdoor Locations ............................................... 21
7.3 Enclosed Locations ............................................... 21
RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OF
CLASSIFIED LOCATIONS-COMMON APPLICATIONS ..................2 1
8.1 General ........................................................ 21
8.2 Recommendations for Areas Surrounding Specific Equipment ............ 21
RECOMMENDATIONS FOR DETERMINING DEGREE AND EXENT OF
CLASSIFIED LOCATIONS IN PETROLEUM REFINERIES ................. 36
9.1 Introduction. .................................................... 36
9.2 Recommendations ............................................... 36
10 RECOMMENDATIONS FOR DETERMINING DEGREE AND EXTENT OF
CLASSIFIED LOCATIONS AT DRILLING RIGS AND PRODUCTION
FACILITES ON LAND AND ON MARINE FIXED PLATFORMS. ........... 44
v
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