STANDARDS / HAZARDOUS AREA STANDARDS ::
 
 
 
Europe/IEC/CENELEC/NEC505 Continuous Hazard >1000hrs/yr
 
Intermittent Hazard 10-1000hrs/yr
 
Hazard under abnormal conditions 0.1-10hrs/yr
North America/NEC500-503
 
Zone 0(Zone 20 dust)
 
Zone 1(Zone 21 dust)
 
Zone 2(Zone 22 dust)
Safety Categories - Vapours
 
Division 1(gases&dusts)
 
Division 1(gases&dusts)
 
Division 2(gases&dusts)
Safety Categories - Dusts
 
G1 G2 G3
  D1 D2 D3
 
Hazard Category ::
 
 
If your company is planning an expansion, retro-fit, grass roots facilities, or simply modifying a process unit, and the process hazard analysis (PHA) indicates you need a safety instrumented system (SIS) as a protective layer, then you need to comply with ANSI/ISA S84.01. Why? Because in February 1996, the "Application of Safety Instrumented Systems for the Process Industries" was approved and will be enforceable under OSHA 29 CFR Part 1910. There are at least five (5) references in this Federal Register that state "...accepted engineering standards and practices". For example :
 
  APPARATUS
 
CLASSIFICATION
 
 
Hazardous Substances

 
Europe NEC 505
 
North America NEC 500-503
 
Ignition Energy
Methane

 
Group I(mines)
 
Class I, Group D
 
>260 microJoules
Gases and Vapours
Acetylene
Hydrogen
Ethyl
Propane
 
-
Group IIC
Group IIC or IIB
Group IIB
Group IIA
 
-
Class I, Group A
Class I, Group B
Class I, Group C
Class I, Group D
 
>20 microJoules
>20 microJoules
>60 microJoules
>180 microJoules
Dusts
Metal Dust
Coal Dust
Grain Dust
-
In Preparation
In Preparation
In Preparation
 
-
Class II, Group E
Class II, Group F
Class II, Group G
 
^ More ^
^ Easily ^
^ Ignited ^
Fibres and Flyings
Wood, paper or cotton fibre processing

 
-
Not Classified
-
Class III
-
-
 
Temperature Classification ::
 
 
MAXIMUM TEMP. SURFACE    

-
Deg. C
 

-
Deg. F
 

EUROPE IEC79-8 T CLASS
EN 50 014

 

NORTH AMERICA
NEC 500-3(d)

 

450

842

T1

T1

300

572

T2

T2

280

536

T2

T2 A

260

500

T2

T2 B

230

446

T2

T2 C

215

419

T2

T2 D

200

392

T3

T3

180

356

T3

T3 A

165

329

T3

T3 B

160

320

T3

T3 C

135

275

T4

T4

120

248

T4

T4 A

100

212

T5

T5

85

185

T6

T6

 
Methods of Explosion Protection ::
 
 
European Practice Zone ATEX Cat. CENELEC EN IEC 60079 American Practice Division General Characteristics
Category 1G     50284 -26     Permits combined methods of protection
General Requirements     50014 0     Basic electrical requirements
Oil-immersion Ex"o" 1, 2 2, 3 50015 -6 Oil-immersion 1, 2 Suitable for transformers and where there are moving parts.
Pressurisation Ex"p" 1, 2 2, 3 50016 -2 Purging 1, 2 Suitable for cabinets, motors, analysers or working area. Requires specific alarm systems.
Powder-filling Ex"q" 1, 2 2, 3 50017 -5 Not Recognised   Suitable for weighing machines and where there are non-moving parts.
Flameproof Ex"d" 1, 2 2, 3 50018 -1 Explosion- proof (1), 2 Suitable for dc motors. Relatively easy to be applied but with specific mechanical requirements.
Increased Safety Ex"e" 1, 2 2, 3 50019 -7 Not Recognised   Suitable for non sparking apparatus during normal operation. (Terminals, connectors, lamp sockets, induction motors etc.)
Intrinsic Safety Ex"ia" 0, 1, 2 1, 2, 3 50020 -11 Intrinsic Safety 1, 2 Suitable for process instruments. Low energy, safe with 2 faults.
Intrinsic Safety Ex"ib" 1, 2 2, 3 50020 -11 Not Recognised   Suitable for displays. Low energy, safe with 1 fault.
Intrinsically safe systems     50039 -25     Considers combination of intrinsically safe apparatus
Type "n" 2 3 50021 -15 Non-Incendive 2 Alternative to standard types of protection.
Encapsulation Ex"m" 1, 2 2, 3 50028 -18 Not Recognised   Suitable for solenoid valves and small circuits and windings.
Special Ex"s" (0), 1, 2       See NEC Section 90-4 For apparatus for which safety can be demonstrated, but not according to any standard method.
 

 Ana Sayfa