Explosion ratings 4

[macklinetc]

Can someone tell me what the codes and definitions are in Europe that are equivalent to the US NEC and specifically the Class 1 Division 2 and Class 1 Division 1 explosion classifications?
Thanks

 

[BECREZ]

Try IEC 79. There is a series within IEC 79 that discusses explosive areas for combustible gasses.

 

[dyn11]

Class 1 Div 1 includes Class 1 Zones 0 and Class 1 Zone 1
Class 1 Div 2 is Class 1 Zone 2

There are three zones: 0 , 1 and 2

 

[hazloc]

Class I div 1 is both explosion proof and intrinsic safety (I.S.)
Exp proof = Flame proof, so an explosion proof box rated as such from UL or FM would be marked by the Europeans as EEx d
The gas groups are:
Class I Div 1 A=C2H2 (ace.) is IIC by Europeans (it also includes Hydrogen when marked IIC)
Group B is Hydrogen = IIC by the Eur.
Group C is Ethylene = IIB by the Eur.
Group D is Propane = IIA by the Eur.

One of the tricks to watch for is the I.S. area
In Class I Div 1 you can use Exp proof or I.S. equip.
In the Zone system only I.S. equip can be used in Zone 0.
(there are other methods that can be used in a Zone 0 but it is tricky and very expensive)
The Zone 1 is Ex d or ib and so an explosion proof box can also be used.
The Zone 2 is Div 2.
Things will get alot more complicated as the (new approach) ATEX directive becomes affective in the end of June 03.
Equipment will have to marked cat 1, 2 or 3 (which was 0,1,2)
Hope this helps.

 

[GLC1]

hazloc
I am wanting to use some ATEX certified electrical heaters to heat natural gas. Customer is requesting NEC certification. Everyone tells me the ATEx is a higher level of certification is that correct.

 

[makpal]

I am not aware of ATEX certification but the testing authorities in Europe are :

Belgium: INIEX, Denmark: DEMKO, France: INERIS, LCIE.
Germany: PTB, BVS, Netherlands: KEMA, Norway: NEMKO,
Spain: LOM, UK: BASEEFA / EECS.

These are the certifying authority for the classified area equipments.

 

[peebee]

I don't believe there's any such thing as NEC certification.

 

[hazloc]

Hello
The NEC stands for the National Electrical Code and is published and owned by the NFPA.
Basically, the NEC is used by electrical installation personnel for rules of installations of equipment. For example, "NEC article 500" is used for hazardous location installations.

The NEC is for installation of equipment and ATEX is for manufacturing of hazardous equipment. Sort of like UL would approve equipment under some standards such as UL1203 or 913.
To say that ATEX equipment is superior would be very difficult to prove. For example an Ex d enclosure may only have 5 explosion tests done inside it where the UL Class I Div 1 piece would have had a minimum of 10 explosions. Flame paths and other tests are also different.

The major difference between an ATEX (Zone Classification only) approved piece of equipment and something approved for a Class I Div 1 piece is that the ATEX piece has to comply with all other directives that may apply to it such as EMC/EMI, low voltage, and the manufacture has a QA or ISO system in place, and has be tested by a Notified Body in Europe.
There are many things I have not mentioned here and of course there are execeptions to the rules.

Your customer may have meant that he/she wants the equipment to be installable as per the National electrical code (most likely Class/Div but possible Zone) and bear markings of an approval agency such as UL/CSA/Entela.

Because natural gas is involved, the area the equipment is going into would be a classified area so the equipment should be marked say Class I (gas vapours) , Div 1 or 2 ( whichever applies) group D.
If it was for Zone, then Ex "and then whatever method of protection is used" and IIA plus the T code.
After reading over what I wrote, I realize that I jumped around a lot so I hope it makes sense.

 

[peebee]

The IEEE IAS magazine this month had an interesting article on what was stated to be the first installation of zone-rated equipment in the US at a refinery in Alaska. It gave a very interesting and detailed description of the differences between traditional and zone-rated installations as well as the problems they encountered and might be helpful for you.

With traditional US XP installations, everything is enclosed in steel. Presumably this would be more durable, although corrosion can be a problem with flanged or threaded flame paths. Field modifications can be difficult to accomplish if existing equipment doesn't have spare hubs.

In Europe, plastic enclosures are used much more extensively.

 

[jack11]

I am looking for information on the requirements or thatthere is not requirement for explosion proofing control wiring to valves in a containment area that has tanks containing Class IIIA Flammable liquids. I am trying to find where in either the NFPA and/or the NEC codes provide some direction on this issue. Your assistance in this matter would be very much appreciated.
Glenn

 

[rbalex]

Jack11, you want NFPA 30 (Combustible Liquids Code) and 497 (Recommended Practice for Area Classification). Actually NFPA 497 is probably adequate since it refers to the appropriate NFPA 30 data. Class III combustible liquids do not create Classified locations in typical temperature ranges.

 

[jack11]

I want to thank you replying to my question. I looked up the code IEC-79 however I am still kind of confused. The NFPA and IEEE use diffent classifications. My real question is; do I need to use Explosion proof equipment/wiring in a tank farm that contains NFPA Class III A/B flammable liquids (Flash point greater than 140 F) in it? The liquid is Recycled Fuel Oils and they are in a containment bunded area with a side wall less than 36" and is outside in the open to the atmosphere.
Thanks

 

[rbalex]

"do I need to use Explosion proof equipment/wiring in a tank farm that contains NFPA Class III A/B flammable liquids (Flash point greater than 140 F) in it?"

No you don't; the area in not Classified under the conditions you have described..

If this is US domestic work IEC - 79 (now IEC-60079 series) doesn't apply at all. It is indeed very different from NFPA standards, despite the force-fit "Zone" system in NEC Article 505, it still quite different.