Firewater required for chemical plant?

[KLee777]

Not sure if this is the right forum, so I will cross-post.

Simple question, how do I determine how much firewater is required for a defined "event" in my plant? Say, if I assume the most hazardous event is that my storage spheres catch fire, where do I then get a "requirement" for how much water/ sq. ft is required to put it out? Can anyone point me in the right direction?

I know how to do this for buildings, but for plants...well, that's just different.

Appreciate any help, as usual.

Thanks,
Kelly

 

[cdafd]

do you have a code or standard you have to design to and what material are you trying to protect

 

[KLee777]

Sorry, I should have been more clear. Was in a hurry.

Knowing the design code is part of the problem. The plant will be located in Venezuela, and I have no knowledge (or guidance from my client) as to the design standards to be used. In general, on this project, we've been directed to use U.S. standards when no other standards are specified.

So I assume NFPA. However, I'm not aware that NFPA gives guidance on system demand, as this is dependent upon the particular hazard.

In the plant, we have large amounts of propylene and hydrogen. We have the propylene in spheres, stored at ~7.9 kg/cm2 (~112 psi) and 10 C (50°F). The hydrogen is stored at high pressure, 185 kg/cm2 (~2600 psi) in bullet tanks.

Hydrogen, Propane, and Propylene are everywhere in the process unit, but by far we have the largest amount in these storage tanks. Large hazard.

I need guidance on not only identifying the worst/most hazardous "event" in the plant, but also how much fire protection (other than client and NFPA 24 standards, which I've already employed) is required.

Thanks.

 

[cdafd]

Seek professional help

you are looking at the wrong resource for your answer

 

[stookeyfpe]

I suspect I would start with NFPA 15. You haven't explained your fire scenario.

You need to dig deeper in the design using NFPA 15. Have fun.

 

[LCREP]

Take a look at FM Data Sheets they are now free at

http://www.fmglobal.com/FMGlobalRegistration/default.aspx?action=new

The following will give you some things to consider:

7-42 GUIDELINES FOR EVALUATING THE EFFECTS OF VAPOR CLOUD EXPLOSIONS USING A TNT EQUIVALENCY METHOD

7-44 SPACING OF FACILITIES IN OUTDOOR CHEMICAL PLANTS

Data Sheet 1-20, Protection Against Fire Exposure

Data Sheet 7-55/12-28, Liquefied Petroleum Gas.

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