Codes that require and govern design of explosion proof rooms

[thomasfrotten]

Where do I find the requirements for an explosion proof room? I am familiar with the NFPA but have not come across what codes governs the design and construction of a bunker type room for the processing of a highly flammable chemical including design of blow out panels and walls.

Any help or road maps to where I should be looking or what type of engineering firm I should be contacting will help. So far im scratching dust and getting very little.

 

[pleckner]

Most E&C (engineering and construction) firms, the one I work for included, can help you with this. I don't know where you are located but you might try the Internation Building Codes (IBC) and Factory Mutual (FM).

 

[cdafd]

some design is in the fire code international or uniform

 

[cdafd]

nfpa will more than likely have more info than the fire code

 

[stookeyfpe]

Why are deflagration vents required for the process? I am not a proponent of these systems because for the vents to work, the volume of vapor must approach the stoichometric limit of the evaluated material. It is far safer (and less expensive in my mind) to spend the money on a reliable mechanical ventilation system if the process is housed indoors.

So what are the process variables including:

-- Materials being handled
-- Operating temperature and pressures
-- Vessel volumes and design
-- Room area and volume

Note that deflagration venting is not always required by NFPA 30 (assuming your dealing with flammable & combustible liquids) and the International Fire Code.

Also, is this process in the United States?

 

[cdafd]

Not an FPE but will be staying at a holiday inn tonight:


Stoichiometric - In terms of flammability limits of gas/air mixtures the stoichiometric mixture is the 'ideal' mixture that will produce a most complete combustion - ie; it is somewhere between the UEL (upper) and LEL (lower) explosive limits and an ignition at the stoichiometric point may result in the most severe deflagration, in relation to those near the upper and lower limits of flammability.

 

[thomasfrotten]

I am working with a highly flammable gas that is in an enclosed system, normal operation will never have fumes and or vapors. The internal system, will be the pure flammable gas, with no air or oxgen, so it will always be above the UEL.

I am using mechanical ventilation to ensure if I have a ruptured line, that the gas concentration in the room will never approach 25% of the LEL which is 4%.

I have done calculations to show that this concentration will never exist if the ventilation is on. I plan on interlocking the supply valve to a positve flow sensor in the duct so it will not be on if there is no ventilation.

I am classifying the room as Class I Div II for the gas.

From what I can tell I should be almost able to argue that this is a general industrial situation, yet in past jobs, that had at least one instance of a similar situation, that facility had blow out panels on the buildings the flammables existed.

I have started reading NFPA codes again and am finding more relevant information, but I definately apprectiate any and all feedback.

Some other details, this room is in the USA and will be modular type construction, and as I am in design phase, It can be what ever best suits the application and code.
Its a production unit that will be servicing a larger oil based production rig that will have operations personell walking around the unit. That is why im worring about blow up panels to release sound and pressure waves and protect people both in and outside of this unit.