Area Classification
Area Classification
(OP)
I had someone at work ask me why we classify plants, processing facilities, etc for Class 1 Div 2, etc, where gas has the potential to leak, but yet, we don't classify our homes around gas stoves and gas water heaters.
Anyone have any thoughts on this.
Thanks
Anyone have any thoughts on this.
Thanks






RE: Area Classification
For the very same reason we don't area classify the works kitchen (containing gas cookers)...Risk / cost balance.
Alan
RE: Area Classification
RE: Area Classification
Further to my last comment, this applies basically when referenced to the Canadian Electrical Code. It is up to the engineer to determine what the classification of an area shall be. If she/he determines that it does not need to be classified, then the engineers classification shall apply. Conducting a fugitive emissions study is one way of accurately determining the classification of an area.
RE: Area Classification
I agree about using API code. What I was really looking for is why inside homes we don't classify equipment or surroundings such as gas stoves and gas water heaters. If you think about it, gas has more "leakage" potential there than it does at at process plant.
But what I told the guy at work, that it really comes down to what someone mentioned earlier.... RISK/COST basis.
RE: Area Classification
For example, percentages of accident involving a gas explosion in residential places may be much lower than those involving electricution or fires due to faulty electrical work.
Many code requirements in modern days are also dictated by Insurance companies which in turn are based on the claims they see.
Plus cost/risk factor is always there.
RE: Area Classification
RE: Area Classification
RE: Area Classification
http://www.come2meet.com/apec/cd/05%20Teh-Sheng%20Su%20-%20Presentations%20on%20Experience%20with%20Hazard%20Communication%20Part%202.ppt
for a high level presentation
RE: Area Classification
RE: Area Classification
The spirit of these documents is to keep an "electrical ignition" from occuring. Many areas with an open flame will be unclassified (for electrical) because the flame will ignite any gas before an electrical ignition can occur. (Like around the water heater in the basement.)Thus, no special electrical gear is required.
RE: Area Classification
I often get asked for explosion proof enclosures and motors on boilers, heaters, and other devices with open flames. Funny how it seldom occurs to some what problem you are really trying to solve by classifying an area, and using explosion proof equipment.
rmw
RE: Area Classification
does not make much sense when open flames are aboundent in the general fcinity does it?
RE: Area Classification
RE: Area Classification
"Adequately ventilated locations surrounding equipment that has continuous flame sources (eg. unprotected fired vessels and flare tips) need not be classified solely by reason of the fuel gas being considered as a source of release.
Note 1: it may be prudent to classify portions of these locations. For example electrical equipment may be exposed to flammable gas during a purge cycle of a fired heater or furnace.
Note 2: The lack of classification around unprotected fired vessels and flare tips does not imply the safe placement of fired vessels and flare tips in the proximity to other sources of release because unprotected fired vessels and flare tips arethemselves sources of ignition. The decision of whether or not it is safe to install the unprotected fired vessel or flare tip at the location is outside the scope of [RP 505]".
RE: Area Classification
RE: Area Classification