Diesel Fuel Storage - Hazardous from control system point of view?

[moeen]

Hi Gents

I am working on a fuel storage and dispensing facility. Initally the storage part was being done by others, and I have completed the design and coding of the dispesning side of it. However, it appears that I might also be now asked to contribute to the fuel storage side.
My question is whether the diesel fuel storage is to be treated as hazardous from control system point of view, and hence will need intrinsically safe barriers (among other things) or not? My understanding is that diesel is not readily flammable (flashpoint above 52 deg C) as petrol and some other fuels.
Thank you for your input.
Cheers.

 

[Tom Jenkins]

I would be very surprised if there wasn't an applicable building code or other statutory requirement that covers this. That would be the first place I'd go for info.

You are right that diesel isn't as flammable or volatile as gasoline. That doesn't mean it isn't still a hazard, and that doesn't mean the codes don't identify precautions that may be erring on the side of caution.

 

[James Mcquade]

Diesel fuel is still flammable - period!
once it catches on fire, get out of the way.
you also have to consider the gas fumes in the tank.

i would look at NEC70 - electrical code. sections 500 to 504 and 514.
500 - hazardous locations
501 - class 1 - flammable liquids
502 - class 2 - dusts
503 - fibers
504 - intrensically safe systems
514 - fuel dispensing systems

there may be others as well

the design engineer should have all this specified in the design.

have you thought of your backup components in case of failures? ask a lot of what if questions, no matter how stupid you think is is or a one in a million shot. if you think of it, plan for it to happen.

regards,
james

 

[Lancie1]

Mooen,

I once did the controls for a 5000 gallon diesel storage/dispensing tank. The only eletrically classified area (Class I Division 1) turned out to be a 5-feet (Divison 1, and 10-feet Division 2) radius around the exit end of the vent pipe. I did not install any electrical equipment in that area, so did not have to use any special equipment. The fuel was pumped out through a buried pipe, so there were no prolbems with fumes from open dispensing. A well-designed grounding system and lightning protection are recommended. I used Ufer grounding because the tank had large deep foundation piers and a thick spill-containment slab.