Fire water Piping 1

[geovar]

There is a small NGL fractionation pLant we are designing and building. The Client at the last minute asks for a Fire water ring and Protection.Now this is a pain and cost a lot which we are trying to avoid commiting.
I would appreciate any guidelines on
What are the criteria for requirement of a Fire water system including any code that specifies criteria on size of plant and capacity .

Thanks
George V

 

[bimr]

The insurance industry will provide you with the requirements. You should contact your clients underwriter for recommendations.

 

[1969grad]

There are several NFPA specifications which address fire water systems requirements. It seems to me from your message that you will need a storage reservoir holding 4 hours of water usage, a 500 min gpm pump, jockey pump and a piping loop with several hydrants.

In the bigger picture you should have already addressed plant layout, equipment spacing, site drainage, etc. as it pertains to minimizing plant damage long ago.

 

[TD2K]

If you have a release of NGL, how do you plan to fight the possible fire?

Right now, your only option is to back away and let it burn itself out. As others have suggested, the insurance people may be less than eager to accept this risk.

 

[geovar]

Thanks

 

[Guidoo]

I agree that the insurance has to be involved in whether you should have a fixed firewater system or not.

However, I do not say that a small NGL plant always should have a fixed firewater system or that there are any NFPA specifications that prescribe you to do so (as 1969grad suggests). Anyway, the size of your firewater pump is determined by your largest fire scenario, so you cannot say that it should be 500 gpm.

I know for sure that there exist NGL extraction plants that do not have a fixed firewater system (in the US).

TD2K asked "If you have a release of NGL, how do you plan to fight the possible fire?"

Note that extinguishing an NGL fire is normally not a good idea, the NGL (mainly a mixture of ethane and propane) will evaporate and if the resulting vapor cloud ignites, you can get an explosion. The firewater (if present) is normally used to keep equipment close to the fire cool, not to extinguish the fire. Cooling equipment is done to prevent equipment rupture because of the weakening of steel at elevated temperatures. However, this can also be prevented by applying fireproofing.

Bottom line is that you should have a good fire and explosion protection strategy in place, in order to ensure that the risks involved remain in the tolerable region. This involves things like layout, fire and gas detection, drainage, passive fire protection (fireproofing) and active fire protection. This strategy normally includes a fixed firewater system, but if this is not practical (e.g. because of the small size of the plant, or because of scarcity of water in the area), you may consider not to have such a system. But again, first you have to convince the insurer that you took sufficient measures to make sure the risks are acceptable.