Article 511 (Commercial Garages) and Diesel vehicles

[steve66]

Since diesel is not a flammable liquid, it appears that a garage that services only diesel vehicles would not need to have any areas classified as hazardous.

I think that's the case, because 511.3 only applies to areas "where flammable liquids or gaseous fuels are stored, handled, or transferred." That's in the first sentence of 511.3

Since 511.3 (D) is a sub-paragraph of 511.3, it would also only apply where vehicles having flammable liquids or gaseous fuels are serviced.

So my conclusion is that a garage that only services diesel vehicles would not have any areas classified as hazardous, even if they do major service work, and they have a service pit, and no special ventilation is provided.

Does anyone else see it the same way, or am I missing something?

Thanks

 

[rbalex]

I agree.

 

[ron]

Do you think any of the other liquids are flammable and are stored, handled, or transferred?

I'm not sure whether motor oil, brake fluid, battery acid, etc would be considered flammable

 

[steve66]

Do you think any of the other liquids are flammable and are stored, handled, or transferred?

I'm not sure whether motor oil, brake fluid, battery acid, etc would be considered flammable

NFPA 30 actually has a chart at the end. (Not sure if it has always been there, or if they recently added it.) I

I deleted the last two columns of the table, and I hope I'm not breaking any copy write laws by posting it.

But it doesn't look like there is any other class 1 liquids except washer fluid. And I believe there is a specific exception for washer fluid.

B.1? Fire Hazard Properties of Typical Flammable and Combustible Liquids Found at Motor Fuel Dispensing Facilities.
Table B.1 lists common liquids typically found at motor fuel dispensing facilities and repair garages and their relevant fire hazard properties.

Table B.1? Typical Flammable and Combustible Liquids Found at Motor Fuel Dispensing Facilities
Liquid	Flash Point (?F)	NFPA 30 Class
Antifreeze	230	IIIB
Brake fluid	300	IIIB
Chassis grease	400	IIIB
Crankcase drainings	?	IIIB
Diesel fuel #1	100	II
Diesel fuel #2	125	II
Diesel fuel #4	130	II
Gasoline	?40 to ?50	IB
Gear lubricant	395	IIIB
Kerosene (fuel oil #1)	100	II
Lithium-moly grease	380	IIIB
Lubricating oils	300 to 450	IIIB
Power steering fluid	350	IIIB
Transmission fluid
?Dexron II	395	IIIB
?Type F	380	IIIB
White grease	465	IIIB
Windshield washer fluid (methanol/water mixtures)
?100% methanol	54	IB
?50% methanol/50% water	80	IB
?29% methanol/71% water	102	II
?20% methanol/80% water	118	II
?5% methanol/95% water	206	IIIB

 

[mgookin]

How about a parts washing system? I've seen some pretty big ones and if this is a diesel only facility, I can guess there's nothing small in that shop.

I'm not trying to be an idiot. Just trying to look out for OP.

Also as always, run it by AHJ before you take your design to the bank. It's much easier to change it on paper than to change it on the Earth.

 

[kwired]

AHJ may want some method of assurance that equipment with other fuels are never serviced in said facility. Though if it is very rarely done there may not be any issue either. After all many people work on cars, motorcycles, lawn equipment, etc. in garages at home and we are not required to treat those garages as having any hazardous locations.

 

[rbalex]

I don't know about other engineers, but I wasn't issued a crystal ball with either my degree or my PE. I doubt AHJs get one either. Unless there is very good reason to believe an installation will have a different future occupancy, such as client desired flexibility, I don't design for someone's speculations. That is for the future designer to deal with. Believe me, I've been on the receiving end of that condition many times myself.

The OP adequately described/analyzed the situation. If incidental flammable materials are proximate to an installation, the whole world would be at least Division 2.

 

[steve66]

I have no idea about a parts washing location, but I wouldn't expect the cleaning solution to be a Class I liquid.

I was thinking about getting a letter from the owner that says gasoline vehicles won't be serviced, or if they are, the service will be minor service work like oil changes and tune ups. Not anything where they have to transfer gasoline. If they keep gasoline vehicles to minor repair, I can classify the pit, and the area 3' around the pit, and that basically meets code.

I think it would be prudent to do that, but I really don't think its necessary. This is a service garage for garbage trucks, and they are all diesel. Some employee may pull his car in at night and change the oil, but I don't think I have to design for that, because its not really the intended use of the building.

I think its similar to a hospital. A patient may occasionally get examined or treated in a corridor, but that doesn't mean the corridor has to be constructed to the same standards as an exam room.