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Engineering Standard
SAES-B-068 23 November 2017
Electrical Area Classification
Document Responsibility: Loss Prevention Standards Committee

Contents
1 Scope ................................................................ 3
2 Conflicts and Deviations ................................... 3
3 References........................................................ 3
4 Modifications to API RP 505
(Reaffirmed, August 2013) ................................ 5
Revision Summary................................................. 17

Previous Issue: 14 August 2014 Next Planned Update: 23 November 2020

Page 1 of 18
Contact: Ghamdi, Salem S. (ghamss1i) on phone +966-13-8729642

©Saudi Aramco 2017. All rights reserved.

Document Responsibility: Loss Prevention Standards Committee SAES-B-068
Issue Date: 23 November 2017
Next Planned Update: 23 November 2020 Electrical Area Classification

API RP 505 Page

Title Remarks
Section No. No.
Section 1 Scope Modified 1
Section 2 References Modified 2
Section 3 Acronyms and Abbreviated Definitions Modified 4
Section 4 Basic Conditions for a Fire or Explosion No Change 8
Section 5 Flammable and Combustible Liquids, Gases, and Vapors Modified 8
Section 6 Classification Criteria Modified 10
Section 7 Extent of a Classified Location Modified 20
Recommendations for Determining Degree and
Section 8 Modified 21
Extent of Classified Locations – Common Applications
Recommendations for Determining Degree and
Section 9 Modified 36
Extent of Classified Locations in Petroleum Refineries
Recommendations for Determining Degree and Extent
Section 10 of Classified Locations at Drilling Rigs and Production Modified 44
Facilities on Land and on Marine Fixed Platforms
Recommendations for Determining Degree and Extent
Section 11 of Classified Locations on Mobile Offshore Drilling Units Deleted 67
(Modus)
Recommendations for Determining Degree and Extent of
Section 12 Classified Locations at Drilling Rigs and Production Facilities Modified 85
on Floating Production Units
Section 13 Reserved for Future Use Deleted 89
Recommendations for Determining Degree and Extent of
Section 14 Classified Locations at Petroleum Pipeline Transportation Modified 89
Facilities
Sample Calculation to Achieve Adequate Ventilation of an
Appendix A No Change 105
Enclosed Area by Natural Means Using Equations 1 and 2
Calculation of Minimum Air Introduction Rate to Achieve
Appendix B No Change 107
Adequate Ventilation Using Fugitive Emissions
Preferred Symbols for Denoting Class I, Zone 0, Zone 1,
Appendix C No Change 109
and Zone 2 Hazardous (Classified) Areas (IEC 79-10, Mod)
Informative Annex – An Alternate Method for Area
Appendix D No Change 111
Classification
Appendix E Procedure for Classifying Locations No Change 119
Annex F Informative. Alternate Ventilation Criteria (IEC 79-10, Mod) No Change 121
Figures Modified 17-125
Tables Modified 10-116

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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
Issue Date: 23 November 2017
Next Planned Update: 23 November 2020 Electrical Area Classification

1 Scope

The API RP 505 - 2013 in its entirety, with all amendments, errata, and supplements
thereto, shall constitute the Electrical Area Classification methodology adopted by Saudi
Aramco except as modified by this standard. The provisions of this standard, hereinafter
referred to as “this code,” shall apply to classify hazardous areas for the purpose of
selecting the appropriate electrical equipment to be installed in that classified area.

Where this standard is supplemented by or is in conflict with specialized requirements

for offshore platforms covered in SAES-B-009 and for bulk plants/air fueling
operations, in SAES-B-070; those standards shall govern.

The electrical classification of areas containing combustible dust (Class II) and easily
ignitable fibers (Class III) atmospheres per NFPA 70 shall be developed with the
concurrence of the Saudi Aramco Chief Fire Prevention Engineer (SA CFPE).

For electrical area classification of low-to-moderate size or batch chemical process

plants involving flammable liquids, gases, or vapors, NFPA 497 can be followed (refer
to table 5.8.4 of NFPA 497, 2017 edition, for the size determination). For non-
industrial installations, such as Laboratories, the relevant NFPA standard can be used.
For continuous or large chemical process plants, API RP 505 shall be used.

2 Conflicts and Deviations

Any conflicts between this document and other applicable Mandatory Saudi Aramco
Engineering Requirements (MSAERs) shall be addressed to the EK&RD Coordinator.

Any deviation from the requirements herein shall follow internal company procedure
SAEP-302.

3 References

The classification of hazardous areas covered by this standard shall comply with the
latest edition of the references listed below, unless otherwise noted.

3.1 Saudi Aramco References

Saudi Aramco Engineering Procedure

SAEP-302 Instructions for Obtaining a Waiver of a Mandatory
Saudi Aramco Engineering Requirement

Saudi Aramco Engineering Standards

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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
Issue Date: 23 November 2017
Next Planned Update: 23 November 2020 Electrical Area Classification

SAES-B-009 Fire Protection and Safety Requirement for

Offshore Production Facilities
SAES-B-070 Fire and Safety Requirements for Bulk Plants,
Air Fueling, and Sulfur Loading Facilities
SAES-J-510 Process Analyzer Systems
SAES-J-903 Intrinsically Safe Systems
SAES-K-002 Air Conditioner Systems for Essential Operating
Facilities
SAES-P-103 Direct Currents and UPS Systems
SAES-T-151 Communication DC Power System

3.2 Industry Codes and Standards

American Petroleum Institute

API RP 500 Recommended Practice for Classification of
Locations for Electrical Installations at Petroleum
Facilities Classified as Class I, Division 1, and
Division 2
API RP 505 Recommended Practice for Classification of
Locations for Electrical Installations at Petroleum
Facilities Classified as Class I, Zone 0, Zone1,
and Zone 2

National Fire Protection Association (NFPA)

NFPA Fire Protection Guide to Hazardous Materials
NFPA 30 Flammable and Combustible Liquids Code
NFPA 30A Motor Fuel Dispensing Facilities and Repair Garages
NFPA 59 Utility LP-Gas Plant Code
NFPA 70 National Electrical Code (NEC)
NFPA 496 Purged and Pressurized Enclosures for Electrical
Equipment
NFPA 497 Recommended Practice for the Classification of
Flammable Liquids, Gases, or Vapors and of
Hazardous (Classified) Locations for Electrical
Installations in Chemical Process Areas
NFPA 820 Fire Protection in Wastewater Treatment and
Collection Facilities

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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
Issue Date: 23 November 2017
Next Planned Update: 23 November 2020 Electrical Area Classification

4 Modifications to API RP 505 (Reaffirmed, August 2013)

The following part, section, and section numbers refer to the API RP 505 (August
2013), which is part of this SAES. The text of each paragraph below is an addition,
modification, exception, or deletion as noted.

SECTION 1 SCOPE

1.2.1.d Scope

(Modification) Classification for locations containing combustible dust

(Class II) and easily ignitable fibers or flyings (Class III) per NFPA 70
shall be developed with the concurrence of SA CFPE.

1.2.7 Floating Production Units (FPUs)

(Modification) Modify to remove references to FPUs, FPSs, FPSOs, and

SALMs and insert Single Point Mooring Buoys (SPMB) and Catenary
Anchor Leg Mooring (CALM) type buoys. For classification of other
types of Floating Production Units, contact SA CFPE.

SECTION 2 REFERENCES

2.2 Government Codes, Rules, and Regulations

(Deletion) Delete in its entirety.

SECTION 3 ACRONYMS AND ABBREVIATED DEFINITIONS

3.2.12 Combustible Liquid (Class II, IIIA, and IIIB)

(Modification) Delete in its entirety and repalce to read “ A combustible

liquid is a liquid that has a flashpoint greater than 54°C.”

(Addition) Combustible gases and vapors are those which can form
flammable or explosive mixtures with air.

3.2.23 Flammable Liquid (Class I Liquid)

(Modification) Delete in its entirety and replace to read “ A flammable

liquid is a liquid that has a flashpoint equal to or less than 54°C.

3.2.27 Gases, Heavier-than-Air

(Modification) Delete in its entirety and replace to read “ Is a gas/vapor

with a density under release conditions that is equal to or greater than
75% of that of air at atmospheric pressure and 15°C.”
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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
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3.2.28 Gases, Lighter-than-Air

(Modification) Delete inits entirety and replace to read “Is a gas/vapor

with a density under release conditions that is less than 75% of that of air
at atmospheric pressure and 15°C.”

3.2.52 Unclassified Location

(Addition) Is a location which is completely outside Class I, Zone 0,

Zone 1 and Zone 2 classified locations.

Also in the “Unclassified location” category are those enclosed spaces,

not containing a release source, in Class I, Zone 0, Zone 1, Zone 2
locations, that are pressurized or purged by inert gas or by air taken from
non-classified locations by systems that comply with type “X” or type
“Z” purging, respectively, per NFPA 496.

3.2.56a Adequately Ventilated Outdoor Location

(Addition) Is any space which is open and free from obstruction to the
natural passage of air through it, vertically or horizontally. Such locations
may be roofed over and/or closed on one side.

3.2.58 Volitile Flammable Liquid

(Modification) Delete in its entirety and replace to read “ Is defined as

any of the following: a flammable liquid, a combustible liquid at a
temperature within 8°C of its flashpoint or at a temperature equal to or
above its flashpoint.”

SECTION 5 FLAMMABLE AND COMBUSTIBLE LIQUIDS, GASES, AND

VAPORS

5.2.1 General

(Modification) Delete in its entirety and replace with the modified

definitions provided in 3.2.12 and 3.2.23.

5.5.5a Mixtures of Gases of Different Densities

(Addition) Add to append the following at the end: “For a gas or mixture
of gases composed entirely of lighter-than-air gases, the extent of the
classified location shall satisfy the requirements for lighter-than-air vapors.

Where a mixture is composed of lighter-than-air and heavier-than-air

gases and the mixture density is less than 75% of the density of air at

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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
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standard conditions, the extent of the classified area shall satisfy the
requirements for lighter-than-air vapors.

Where the mixture has a density equal to or greater than 75% of air at
standard conditions, it shall be considered as a heavier-than-air vapor for
area classification purposes.”

5.5.5b Mixtures of Gases or Vapors of Different Ignition Temperatures

(Addition) Add to append at the end: “Where a mixture of gases or

vapors is composed of gases/vapors of different ignition temperatures,
designation of the ignition temperature of the mixture shall be by any
one of the following methods:

5.5.5b.1 The ignition temperature of that gas/vapor in the mixture having the
lowest individual ignition temperature per NFPA Fire Protection Guide
to Hazardous Materials.

5.5.5.b.2 The ignition temperature of the mixture as determined by a test specified

in the Fire Protection Guide to Hazardous Materials.

5.5.5.b.3 The ignition temperature as determined by calculations that have been

reviewed and accepted by the SA CFPE, Dhahran.”

5.5.5c Mixtures of Gases of Different Groups

(Addition) Add to append the following at the end: “Where a mixture

contains gases of different Groups, the area classification shall satisfy the
requirements for every Group for which the aggregate volume of gas
constitutes 25% or more of the mixture composition. For example,
where hydrogen sulfide is present in hydrocarbons, the mixture shall be
considered Group IIA if the H2S constitutes less than 25% of the mixture
by volume, but is Group IIB if 25% or more.”

5.5.6 Gas Group Reclassification

(Modification) In Table 1, change “Group A” and “Group B” to “Group

IIC.”

SECTION 6 CLASSIFICATION CRITERIA

6.5.7 Classification restrictions

(Modification) Delete in is entirety and replace with the following:

For new facilities and extensions/additions to existing facilities, locations

shall be classified using the Class I/Zone/Group method.
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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
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Extensions/additions to existing facilities already classified by the

“Division” method can be classified by the same method with
concurrence from SA CFPE. The following guidelines should be used
when converting an existing Division/Group classification to a
Zone/Group classification.

Gas Group Reclassification

a) Change “Group A” and “Group B” to “Group IIC”.
b) Change “Group C” to “Group IIB”.
c) Change “Group D” to “Group IIA”.

Electrical Area Reclassification

a) For Division 1 areas have the electrical area classification drawings
approved by the SA CFPE.
b) Change “Division 2” areas to “Zone 2” areas
Commentary Note:

For existing facilities that are not yet reclassified, P&CSD (Instrument Unit
Supervisor) and the SA CFPE or their representatives shall approve Zone
1 certified instrumentation within an existing Division 1 area. Zone 1
equipment may not be appropriate since Division 1 contains both Zone 1
and Zone 0 conditions. Only listed intrinsically safe equipment shall be
installed in Zone 0 conditions per SAES-J-903.

SECTION 7 EXTENT OF A CLASSIFIED LOCATION

7.1 General

(Addition) Area Classification Drawings shall be developed for all

facilities where flammable liquids, gases, or vapors are produced,
processed, stored or handled.

(Addition) These drawings shall be produced as part of any project

proposal, final design, and as-built issue of drawings for any capital or
maintenance project that creates or changes the extent of an electrically
classified location. Electrical area classification drawings shall be
submitted to the SA CFPE (Loss Prevention Department) and the
Electrical Engineering Division (Consulting Services Department) or
their representatives for review. The drawings shall, as a minimum,
show the following information:
a. The demarcation of the Zone 0, 1, 2 and unclassified areas, both
vertically and horizontally via plan, elevation, and section views.

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b. The relative density and Minimum Ignition Temperature of the

mixture of gases/vapors creating each classified location.
c. A list of sources of release.
d. The type of gas or vapor in each of the classified areas. This shall
be presented as the name(s) of the gas/vapor and by the Group IIA,
IIB, or IIC designations.

SECTION 8 RECOMMENDATIONS FOR DETERMINING DEGREE AND

EXTENT OF CLASSIFIED LOCATIONS - COMMON APPLICATIONS

8.1a General

(Modification) Modify to insert that where Figure 20, 21 or 22 is

referenced anywhere in this Standard, the “additional Zone 2 area” is
mandatory.

8.1b (Modification) Modify to insert that the pipeways at grade which are
bordered by elevated roads or dike walls, all of height 1 m or greater, on
two sides shall create electrically classified locations as follows:
- Nonclassified: When the minimum distance between the outer edge
of the pipeway and the closer wall is 30 m or greater.
- Class I, Zone 2: When the minimum width between dike walls or
roads is 30 m but the minimum distance between the outer edge of the
pipeway and the closer wall is less than 30 m.
- Class I, Zone 1: When the minimum width and length is less than 30
m.

8.1c (Modification) Modify to insert that in tank farm areas, pumps which are
located at the edge of a pipeway and which are bordered on the other
three sides by dikes or walls of
1 m height or more shall create classified locations as follows:
- Class I, Zone 1: When the linear dimension between opposite
walls is less than 30 m.
- Class I, Zone 2: When the linear dimension between opposite
walls is 30 m or greater.

8.1d (Modification) Modify to insert the following:

Laboratory hoods, ducting, and storage rooms shall be classified as

follows:
a) Enclosed space of fume hood: Class I, Zone 1.
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b) Exhaust ducting associated: Class I, Zone 1 with fume hoods.

c) Vent for exhaust ducting: Per requirements of paragraph 8.2.3.1
for vents.
d) Storage rooms for samples and chemicals: Per requirements of
paragraph 8.2.8.4.

8.2.2 Tank Cars and Tank Trucks

(Modification) Modify to insert an exception that for onshore Bulk

Plants, a diesel or molten sufur loading rack shall be non-classified (see
also section 8.2.8.2).

For onshore bulk plant or fuel terminal loading / unloading bays, the
general 3-dimensional area within truck loading rack curbs and between
grade and the canopy, shall be Class I, Zone 2 for the purposes of
installing fixed instrumentation and electrical equipment such as lighting
fixtures.

8.2.3.1 Process Equipment Vents and Drains

(Modification) Modify to replace Fig. 14 for the vents and insert for the
terminations of vents and drains of process equipment (this includes
vents and drains on all instrumentation impulse lines containing volatile
liquids or combustible gas) that have to be opened to the atmosphere as
part of the normal operation, to be classified as follows:
a) Figure 20 and 21, when the source is adequately ventilated and the
gas/vapor is heavier than air.
b) Figure 24, when the source is adequately ventilated and the
gas/vapor is lighter than air.
c) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.
d) Figure 25, when the source is inadequately ventilated and the
gas/vapor is lighter than air.
e) Vents and drains that are installed solely for hydrotest, steam-out,
and maintenance and that are plugged or blinded, shall not be
designated as release points.
f) Vents and drains to the atmosphere on fired equipment and other
equipment having a continuous source of ignition shall be
considered a release source.

8.2.3.4 Relief Valves and Rupture Disks

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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
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(Modification) Modify to exclude Fig. 18 for relief valves venting to

atmosphere. For all heavier than air cases, the “additional zone 2 area” is
mandatory. The classified area shall be determined by:
a) Figure 20, or Figure 21, when the source is adequately ventilated
and the gas/vapor is heavier than air.
b) Figure 24, when the source is adequately ventilated and the
gas/vapor is lighter than air.
c) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.
d) Figure 25, when the source is inadequately ventilated and the
gas/vapor is lighter than air.
e) The termination of a relief valve discharge, the associated weep
hole, and the bonnet vent shall each be a “source”.
f) A non-flowing pilot on a pilot-operated relief valve shall not be a
“source”.

8.2.4 Marine Terminal Handling Flammable Liquids

(Addition) Add to include offshore oil and product loading facility.

Commentary Note:

A comprehensive location classification for a marine terminal would

include classified locations due to other release points present on the
loading facility. For example, when water level changes may result in
vapors from cargo tank vents, ullage openings or sump vents to collect
underneath the berth deck, consideration should be given to classifying
underneath the deck as Zone 1. Most ships have elevated venting or
high velocity valves which should prevent ship source vapors from
being a continuous problem, but each facility should evaluate this
depending on its service and layout. This requirement and Figure 19
represent classification due only to ship venting, loading arms and
hoses. It does not consider other sources of vapors such as slop tank
vents, relief valves, or vapor recovery compressors.

8.2.6 Batteries

(Modification) Modify to insert that battery rooms that are adequately

ventilated according to requirements in SAES-P-103 and SAES-T-151 are
non-classified. For interiors of unventilated battery rooms, electrical area
classification shall be Class I, Zone 1, Group IIC. Refer to SAES-K-002
for further requirements.

8.2.8 Special Systems

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(Addition) Add to include that classified area shall be determined for

“Special Systems” as follows. The areas in the following systems shall
be classified with reference to the noted sections from NFPA. Areas
classified under the Division classification system should be reclassified
as Zone 0, Zone 1 and Zone 2. Where the referenced standard has not
been updated to zone classification, use API RP 505 with sound
engineering and safety design:

8.2.8.1 Aircraft Hangars: NFPA 70, Article 513

8.2.8.2 Bulk Storage Plants and Aircraft Fueling Systems: NFPA 70, Article 515

8.2.8.3 Commercial Garages Repair and Storage: NFPA 70, Article 511

8.2.8.4 Container and Portable Tank Storage: NFPA 30, Chapter 4

8.2.8.5 Gasoline Dispensing and Service Stations: NFPA 70, Article 514;
NFPA 30A, Chapter 6

8.2.8.6 Spray Application, Dipping, and Coating Processes: NFPA 70,

Article 516

8.2.8.7 Health Care Facilities: NFPA 70, Article 517

8.2.8.8 Facilities that store or handle of liquefied petroleum gas (LP-Gas):

NFPA 59, Chapter 1

8.2.8.9 Sewage Treatment Plants and Collection Facilities: NFPA 820

SECTION 9 RECOMMENDATIONS FOR DETERMINING DEGREE AND

EXTENT OF CLASSIFIED LOCATIONS IN PETROLEUM
REFINEREIES

9.2.3 Separators, Dissolved Air Floatation Units, and Biological Oxidation

Units

(Modification) Modify to include the following:

Drainage ditches, swales, and associated remote impounding basins

(located in unclassified areas) for process location surface drainage shall
create a Class I, Zone 2 location, as follows:
a) Within ditches and swales.

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b) The space between grade elevation and 0.6 m above the top of
ditches and swales. This shall extend from the centerline of the
ditch or swale at this elevation to points 4.5 m from the edges of
the ditch or swale.
c) Within an impounding basin, up to the top of its dike.

Pits, sumps, open trenches, and any other below-grade locations in Class
I, Zone 2 locations shall be classified as Class I, Zone 1.

9.2.3.1 (Modification) Modify to include the following:

Oily water sewer systems shall be classified as follows:

Class I, Zone 0 locations shall be:

a) Within manholes.
b) Within catch basins.
c) Within lift stations and sumps.
d) Within all underground piping.
e) Within all vents.
f) Within .5 m of the termination of vents from the following:
manholes, lift stations, sumps, underground piping systems per
Figure 14 b).

Class I, Zone 1 between 0.5 m and 1.5 m from the vents of the
following: manholes, lift stations, sumps, underground piping
systems.

Class I, Zone 1 within 1 m and Class I, Zone 2 between 1 m and 1.5

m from an access hatch to an enclosed lift station or sump.

Class I, Zone 2 within 1.5 m and 3 m from the vents of the

following: manholes, lift stations, sumps, underground piping
systems.

Class I, Zone 2 within 1.5 m from a manhole, enclosed lift station or

enclosed sump.

As indicated on Figure 27 for unit separators, pre-separators, and

separators.

Sanitary sewer systems shall be classified as follows:

Class I, Zone 1
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a) Inside lift stations.

b) Space within 1.5 m of termination of vent from lift stations.
Refer to API RP 505, Figure 14 a).

Class I, Zone 2
a) Space between 1.5 m and 3 m of termination of vents from lift
stations.
b) 0.6 m from the edge and 0.6 m above the cover of a sanitary
sewer lift station.

SECTION 10 RECOMMENDATIONS FOR DETERMINING DEGREE AND

EXTENT OF CLASSIFIED LOCATIONS AT DRILLING RIGS AND
PRODUCTION FACILITIES ON LAND AND ON MARINE FIXED
PLATFORMS

10.1 General

(Modification) Modify to exclude mobile platforms.

10.3 Production Facilities

(Modification) Modify to exclude Beam Pumping Wells, Mechanically Driven,

Rotating, Subsurface Pumps, Hydraulic Subsurface Pumping Wells, and
Plunger Lift Wells, and Through Flow Line (TFL) tool launcher or
receiver.

10.5.2.1 (Deletion) Delete in its entirety.

10.5.2.2 (Deletion) Delete in its entirety.

10.5.2.4 (Deletion) Delete in its entirety.

10.5.2.6 (Deletion) Delete in its entirety.

10.6.3 Hydrocarbon Pressure Vessel

(Modification) Modify to insert for the manways and piping-to-vessel

connections on process equipment, and sealless canned motor pumps, the
classified area shall be determined by:
a) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.

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b) Figure 25, when the source is inadequately ventilated and the

gas/vapor is lighter than air.
c) When the source includes vents/drains/instrumentation impulse
lines containing volatile liquids or combustible gas, that have to be
opened to the atmosphere as part of normal operation and is
adequately ventilated, the Class I, Zone 2 area shall extend for 3 m
around it. This is for all gases/vapors, irrespective of whether they
are lighter than air or heavier than air.
d) Connections on adequately ventilated vessels and equipment
containing fuel gas at a maximum gauge operating pressure of 350
kPa (50 psig) shall not be considered release sources.
e) Connections on furnaces, fired boilers, fired heaters, incinerators,
and other equipment containing open flames shall not be
considered release sources.

10.6.6.2 (Deletion) Delete in its entirety.

10.9 Compressor or Pump Handling Flammable Liquids, Gases, or Vapors

(Modification) Modify to exclude Figs. 51 to 54. For packing glands or

seals on pumps and compressors the classified area shall be determnined
by:
a) Figure 20, Figure 21, when the source is adequately ventilated and
the gas/vapor is heavier than air.
b) Figure 24, when the source is adequately ventilated and the
gas/vapor is lighter than air.
c) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.
d) Figure 25, when the source is inadequately ventilated and the
gas/vapor is lighter than air.

10.14 (Deletion) Delete in its entirety.

10.15.1 Screwed Connections,Flanges, Fittings, Valves, Valve Stems, And

Check Valves

10.15.1.1 (Modification) exclude the section and insert the following:

For threaded fittings that are not seal-welded, the classified area shall be
determined by:
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a) Figure 20, Figure 21, when the source is adequately ventilated and
the gas/vapor is heavier than air.
b) Figure 24, when the source is adequately ventilated and the
gas/vapor is lighter than air.
c) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.
d) Figure 25, when the source is inadequately ventilated and the
gas/vapor is lighter than air.
e) Adequately ventilated threaded fittings that are not seal-welded
shall not be considered release sources when containing fuel gas
with a maximum gauge operating pressure of 350 kPa (50 psig).

10.15.1.3 (Modification) Modify to exclude the section and insert the following:

For flanges, fittings, and valve stems, the classified area shall be
determined by:
a) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.
b) Figure 25, when the source is inadequately ventilated and the
gas/vapor is lighter than air.
c) When the source is adequately ventilated, it shall not create a
classified location.

10.15.3 (Modification) Exclude the subsections and insert the following to

determine the classification of the atmospheric terminations of sample
stations:
a) Figure 20, Figure 21, when the source is adequately ventilated
and the gas/vapor is heavier than air.
b) Figure 24, when the source is adequately ventilated and the
gas/vapor is lighter than air.
c) Figure 22, when the source is inadequately ventilated and the
gas/vapor is heavier than air.
d) Figure 25, when the source is inadequately ventilated and the
gas/vapor is lighter than air.
e) When sampling frequency is equal to or greater than once a week,
the space within 1.5 m of the termination (the “source”) shall be
classified as Class I, Zone 0 in Figures 20, 21, 24, and 25.

10.16.3 (Modification) Update the section to include the following:

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Document Responsibility: Loss Prevention Standards Committee SAES-B-068
Issue Date: 23 November 2017
Next Planned Update: 23 November 2020 Electrical Area Classification

The interior of analyzer houses shall be classified as Class 1 Zone 1 and

group consistent with liquids or gases being handled. Ventilation and
other requirements for electrical equipment installed in analyzer shelters
may reduce the analyzer house interior classification to
Class I, Zone 2 provided that all features required by API RP 505 and
NFPA 70 for that classification are in the design. Other requirements for
specific electrical equipment installed in analyzer shelters are found in
SAES-J-510.

SECTION 12 RECOMMENDATIONS FOR DETERMINING DEGREE AND

EXTENT OF CLASSIFIED LOCATIONS AT DRILLING RIGS AND
PRODUCTION FACILITIES ON FLOATING PRODUCTION UNITS

(Modification) Modify to include the following:

Single Point Mooring Buoys (SPMB) are classified as Class I, Zone 2

locations to a distance 1.5 m vertically above the highest possible
hydrocarbon release source and horizontally to the outer edge of the
buoy. The inner chamber of Catenary Anchor Leg Mooring (CALM)
type buoys is classified as a Class I, Zone 0 location.

SECTION 13 RESERVED FOR FUTURE USE

(Deletion) Delete in its entirety.

SECTION 14 RECOMMENDATIONS FOR DETERMINING DEGREE AND

EXTENT OF CLASSIFIED LOCATIONS AT PETROLEUM
PIPELINE TRANSPORTATION FACILITIES

14.3.7 Storage Caverns

(Deletion) Delete in its entirety.

Revision Summary
14 August 2014 Revised the Next Planned Update, reaffirmed the content of the document, and reissued as
major revision.

23 November 2017 Major revision to update/reaffirm the contents of the document and align with the API RP
505, (Reaffirmed in August 2013). In this revision, guidelines on conversion to Zone from
Division for existing facilities and requirements for submitting Electrical Area Classification
drawings has also been added. Scope has also been modified to address electrical area
classification of low to modertae size or batch chemical process facilities.

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