Explosion proof and fire proof

Waiting for someone else to go first.

My understanding is that explosion proof means that it will contain any likely internal explosion without venting hot material to the outside. It's used in explosive atmospheres for obvious safety reasons.

Fireproof (actually fire resistant) means that the contents will not be significantly damaged by an external fire. (This is the one I'm not sure of but, hey, someone had to go first.)

Maybe OP writer meant something like this?

"I just want to know the difference[s] of between explosion[ proof] and fire proof, [that is, in terms of] specific differences. [I need to know] Bbecause, base on theits instrument data sheet indicating [one instrument base option is characterized as] explosion proof other[and another option] is [characterized as] fire proof[.] pPlease help me ... because it's my responsibility to verify [qualify and/or validate] the supply [?? - supplied?/power supply?/supplier of?/ratings of?/...? the] instrument base [to be chosen from those shown] on the [vendor's] data sheet."

Response:

Thank you, and Gwen, too, for daring to go first. Whoever OT-graded #1's (Guest's) response (possibly OP writer as well)...I'm not sure (s)he understood its significance. Obviously, both terms are relative...there must be some criteria by which to measure any thing's "proofness" to fire or explosion. Guest's asking (now) about standards, however, is a step in the right direction.

I would offer, that Guest's first step should be an inquiry addressed to the vendor (the data sheet publisher). In order to pass legal muster, the vendor would need to have (tested and) written to one or more applicable standards—in fact I'm surprised that Guest did not find it/them, footnoted, on the data sheet—and is arguably in the best position to offer advice regarding Guest's specific application.

As to the two terms, while claiming no expertise, I have been given to understand that in the case of storage containers/vaults, the term "safe" can only be used legally if the container contents are fully protected from any effects of any reasonably foreseeable fire event; "fire resistant," on the other hand, would allow for some, exposure-time-based, effects (e.g., charring) of the contents, in which case a term like money/strong box could be legally applied. (A practical offshoot: if a vendor or retailer offers a "safe" (so indicated on shelf tag or product package), and if the product, itself, does not also show a "fireproof" certification, then (1) it is not legally a safe and (2) it is unlawfully offered for sale under a false pretense.

About my editing of "verify" in favor of "qualify/validate" in the opening rewrite...

Verify was edited because verify, by definition, would entail Guest (himself) actually undertaking the performance of (potentially) destructive testing on the base(s)...a repetition of the vendor's testing (in oder to legally make the claims) which I am dubious that Guest's employer would be willing to authorize.

I would also offer that Guest's study might need to encompass the grading (consumer, commercial, military, hospital, manned, unmanned, etc.) and environments (terrestrial, marine, sheltered, unsheltered, etc.) for which the candidate instrument is characterized.

Can you please be more specific?

What kind of equipment is it?

What are the requirements set upfront before selecting the instruments?

Do you have to comply to NEMA, IEC, EN or other electrical codes?

The world of explosion prevention is confusing, the IEC ex approach is a good one to get through the confusion. but If you are within the US: request the authority having jurisdiction for an approval to use the equipment, solved and as they took the decision they took the risk.

Please create yourself a user name, give it some geographical info and if needed we can help in the background.

You guys have the technology! Yeap you got it sometimes is kind of a mistery because as you know some called -'Explosion Proof'- and or -'Fire Proof'- and also -'Spark Proof'- but sounds like it have to content the heat anyway somehow in order to avoid further damage around I believe. Smart answers all I agree absolutly. Also will be nice to hang couples of a -No Smoke- signs around just in case, you know how it is sometimes. Good to install a nice ventilation exhaust units too to keep fumes build up in the area and ' Flame/Fuse Safety Close Valves' for the worst case scenario to shut-off material flow to hazardous areas as well 'just in case'. Allset Buddy's, have fun and not rush into nothing. Lock and Tag before anything else and...

Keep it Cool,

MC

An explosion proof encloser will contain and dissipate the heat and pressure from an internal explosion.It dissipates the heat by creating a very long path for the pressure to exit: around all of the threads.Look closely at the threads of an explosion proof enclosure and you will be able to see the path hot gas has to follow.

As far as fireproof,I am not certain, but if the name implies funtion, then it will resist the spread of fire for a certain period of time,usually rated in hours.Wires passing thru a firewall must have a firestop of a certain rating, and be sealed with an approved firestop caulking.

hope this is helpful.

Yes you are exactly right. Please register & identify yourself and we all will make a good team.

Fireproof I believe is that its body material are fire retardant but then again the heat from the fire can damage the internals (say a solenoid/circuit) . In explosion proof if there is short circuit and catches fire that fire as you have written will diaaipate safely.

The application of explosion proof depends on the environment say a petroleum application or a missile making plant or where explosive is stored.

There is a lot of wrong interpretation in the world of explosion prevention.

The need is way more than petrolium companies and missile fabrication.

A simple grain storage is a very dangerous environment, not to speak of flour and sugar powder which can form really nasty explosive environments.

Simple chemical cleaing agents that are used to flush the pipework in food and beverage processing can also create flammable gasses; the normal operation of the plant is harmless but once a week they prepare for the weekend.

Do the datasheets say what standards these devices conform to ? If so you could look those up. Explosion proof and fire proof can both mean different things in different situations.

In any case are you starting from the right place ? Shouldn't you be starting from the actual requirements of your plant/application ?

Steve
MTL Instruments
www.mtlblog.com

Hi

Most of the new facilites will have

1) Area Classification drawing

2) Fire Hazardous Classification drwaing

Depending Upon the Zone , that is where you are placing your Instrument You will have to select the Certified Instrument/Cable (Mgo -SIO2)

Regards

Jose

As one reader stated, check with the manufacturer for their definitions and also check with your company to see if your company has any definitions. Hopefully the definitions will match, but sometimes they won't. A couple readers stated that explosion-proof meant that it would contain an internal explosion. This can be an extremely beneficial quality, however, most of the "explosion-proof" equipment that I have seen (labeled as such) simply meant that it could be used in an environment where an explosion was a hazard usually due to the use of accelerants, natural gas, or the presence of dust etc and it would never cause an explosion. This usually means that it will not cause or produce sparks. Which do you need; to contain an internal explosion due to the nature of the piece of equipment or to prevent a potential explosion due to a hazardous environment?

Fire-proof is usually a statement not that it won't be harmed by fire but that it will not burn which could potentially make the fire worse or allow the fire to become worse. If you are buying a safe "fire-proof" actually does mean that the contents will be unharmed. This may also be true of some pieces of equipment - up to some given temperature or heat load at least.

Bottom line - check definitions. These mean different things to different people and different types of equipment manufacturers - especially if language translation is involved. What your boss means when he uses those words may not be the same as when the manufacturer uses those words.

i want also to know what is the different in Materials of fire and explosion proof? example the instrument housing/casing materials

Explosion proof and fire proof are two different application to specify electrical enclosures

The explosion proof are based on the area classification identified by Electrical Engineer during design stage for electrical enclosure, mostly in hazardous area e.i. refinery, petrochem, and dust or powder producing manufacturing. Mostly, Class 2, Div 1, Grp B, C, D for Refinery and Petrochem. Remember, these are from the area classification design by Electrical Engineer.

Explosion proof electrical enclosure type are usually preventing accumulation or trapped volatile gas to electrical enclosure by means of seals and type of cable glands. that any spark or electrical arc ignite inside the enclosure prevent also by airtight covers with rubber rings by double hinged doors. The enclosure itself are made by casted metals or plactic (PVC, PE). Meaning this enclosure preventing explosion and fire coming from inside enclosure.

While, the fire proof enclosure are protecting inside devices from outside source fire or fire produced by explosion.

Explosion Proof enclosures are not designed to prevent flammable gas/air mixtures entering, they can't be as it is sometimes necessary for an enclosure to be opened for maintenance purposes in the presence of flammable gas (with all sources of power disconnected). However should an explosion subsequently take place, it will be contained within the enclosure and not allow hot gases or sparks to affect the surrounding enviroment.

Steve
MTL

www.mtlblog.com

The term that is often referred to in IEC standards is "Flameproof" (Zone system) which is along the same line of Explosion Proof (Division system) from the stand point of allowing a flame to escape from within the housing where the spark and potential gas may be present. The primary idea is that the ignition of a gas or dust must be contained inside of the housing. For transmitters there achieve this through the number of engaged threads for the sealing surface. so the main idea is that the overiding authority either NEC or IEC will deterimine the final wording of Explosion or Flame proof...

Hope this Helps

A slide from one of the presentations... shedding some light hopefully...