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ATEX ve AMERİKAN STANDARTLARINA GÖRE Ex İŞARETLEME |
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Europe/IEC/CENELEC/NEC505 |
Continuous Hazard
>1000hrs/yr
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Intermittent Hazard
10-1000hrs/yr
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Hazard under abnormal
conditions 0.1-10hrs/yr |
North
America/NEC500-503
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Zone 0(Zone 20 dust)
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Zone 1(Zone 21 dust)
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Zone 2(Zone 22 dust) |
Safety Categories -
Vapours
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Division
1(gases&dusts)
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Division 1(gases&dusts)
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Division 2(gases&dusts) |
Safety Categories -
Dusts
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G1 |
G2 |
G3 |
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D1 |
D2 |
D3 |
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Hazard Category
:: |
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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 : |
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Hazardous Substances |
APPARATUS |
CLASSIFICATION |
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Europe |
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 |
- |
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Temperature Classification
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MAXIMUM TEMPERATURE |
Deg. C
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IEC60079-0
T CLASS
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NORTH AMERICA
NEC 500-3(d)
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450 |
T1 |
T1 |
300 |
T2 |
T2 |
280 |
T2 |
T2 A |
260 |
T2 |
T2 B |
230 |
T2 |
T2 C |
215 |
T2 |
T2 D |
200 |
T3 |
T3 |
180 |
T3 |
T3 A |
165 |
T3 |
T3 B |
160 |
T3 |
T3 C |
135 |
T4 |
T4 |
120 |
T4 |
T4 A |
100 |
T5 |
T5 |
85 |
T6 |
T6 |
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Methods of Explosion
Protection :: |
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European Practice |
Zone
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ATEX
Cat. |
CENELEC EN |
IEC
60079 |
American Practice |
Division |
General Characteristics |
Category 1G |
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50284 |
-26 |
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Permits combined methods of
protection |
General Requirements |
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50014 |
0 |
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Basic electrical requirements
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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 |
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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.
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Increased Safety Ex"e" |
1, 2 |
2, 3 |
50019 |
-7 |
Not Recognised |
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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 |
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Suitable for displays. Low
energy, safe with 1 fault. |
Intrinsically safe systems |
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50039 |
-25 |
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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 |
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Suitable for solenoid valves
and small circuits and windings. |
Special Ex"s"
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(0), 1, 2 |
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See NEC Section 90-4 |
For apparatus for which safety
can be demonstrated, but not according to any standard method. |
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