Bulk Storage Tank Farm

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I'm having trouble understanding Table 515.3 Tank-aboveground.
In a large storage area (100' x 1000') with several tanks the dike height is only 5'.

What classification would inside the dike wall be?:-?
 
Look at API-RP500 and maybe even NFPA 30. I'd recommend you get these on your shelf for aiding your design efforts.

The NEC isn't very good for some industrial applications.

cf
 
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You need to know the gases present and if they are so under normal operating conditions or totally contained ,,,,,,,,,,,the parameters for Area Classification are normally established by an Electrical & Process Engr collectively,an Instrument Engr.is sometimes present as well and this all gets client buy in,,,,,,,,,,,at least that has been my experience,,,different strokes for different folks, but API-RP500 is the governing doc as a rule.

dick
 
hardworkingstiff said:
Most likely a C1D1 location.
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Division 1 isn't too likely.

I thought Table 515.3 was pretty clear; but it may only be from familiarity.

From Table 515.3 with respect to a dike:
Tank ? aboveground

Division 1 ? inside dike where dike height is greater than the distance from the tank to the dike for more than 50 percent of the tank circumference

Shell, ends, or roof and dike area

Division 2 within 3.0 m (10 ft) from ? tank; also, area inside dike to level of top of tank
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If the distance from tank to dike is greater than the 5? dike height mentioned in the OP, the dike will not create a Division 1 location. Otherwise, it is Division 2 inside the dike. Note there may be other Division 1 locations inside the dike caused by other geometry of the system (like a pit) but the dike alone does not cause the Division 1.

This all assumes heavier-than-air, Class I (note the "Roman" one) Flammable material.
 
I agree with Robert B. but things do cause different scenarios,,,you as the contractor are not responsible for determimning Area Classification.

dick
 
Agree with posts 6 & 7, but am offering a heads up - industry is going to start getting tight since BP and an incident here in Alaska at pump station 9 on the TAPS. The pipeline, in it's automated state, chose poorly on a valve functionality, resulting in oil escaping a tank, and a response into overdrive. The event was overblown by the news media, and presstitutes swarmed, what does this mean? That anything to do with oil and dikes, will be in hyperdrive, write your contingencies, into your contracts with capital CYA direction!
 
Rockyd said:
Agree with posts 6 & 7, but am offering a heads up - industry is going to start getting tight since BP and an incident here in Alaska at pump station 9 on the TAPS. The pipeline, in it's automated state, chose poorly on a valve functionality, resulting in oil escaping a tank, and a response into overdrive. The event was overblown by the news media, and presstitutes swarmed, what does this mean? That anything to do with oil and dikes, will be in hyperdrive, write your contingencies, into your contracts with capital CYA direction!
Click to expand...
I can certainly see how containment may be an issue; how is electrical area classification affected (or perceived to be affected)?
 
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