Max firewater demand scenario
Max firewater demand scenario
(OP)
I am new to fire area. I learnt that the capacity of firewater supply system (or station) for a petrochemical plant should be equal to the maximum firewater demand scenario only. There is no need to cover 2 or 3 scenarios at the same time.
Can anyone tell me relevant NFPA chapter for the above sentences.
Can anyone tell me relevant NFPA chapter for the above sentences.





RE: Max firewater demand scenario
RE: Max firewater demand scenario
Years ago, a gas and diesel tank farm I consulted for was annexed by the local city. The local county had required next to nothing for fire protection (a single 750 gpm well pump and a loop of 4" pipe with wharf head hydrants), but the City had other ideas. I worked closely with the city's fire department to establish the design criteria for the new fire protection system. The fire engineer I worked with showed me some forensic studies for fires at other tank farms. As I recall, these studies indicated that, in the absence of a foam system, a fire flow on the order of 10,000 gpm to 15,000 gpm was required to suppress the worst of the fires. With a foam system, about half that was required. Unfortunately, the nearest city main was almost two miles away. There was a small semi-rural water company about 3/4 mile away to the edge, but that system was barely able to supply it's maximum fire of 1500 gpm. In the end, we agreed on two 2500-gpm diesel-driven well pumps feeding loops of 12-inch pipes, and a foam injection system. I had modeled the water company's system and determined that the well and piping upgrades that would have been required to enable that system to serve the tank farm were better and cheaper placed at the tank farm.
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RE: Max firewater demand scenario
While stookeyfpe's statement is true, the NFPA has codes for specific installations and equipment used by petrochemical plants. Before you start digging for these codes, you should read the Fire Protection Handbook in which specific subjects are covered. For example there are sections such as Chemical Processing Equipment, Storage and Handling of Chemicals, Automated Process Equipment, controls of electrostatic ignitions, Flammable and Combustible liquids and the list is endless for your petrochemical plant. You also have OSHA regulations such as Process Safety Management. You can also contact your fire insurance carrier since insurance companies have guidelines for the quantity (in gpm)of water, duration (in minutes or hours) of the water supply, requirement on the number of fire hydrants, installation of chemical extinguishing system, number of portable fire extinguishers.
RE: Max firewater demand scenario
Link
They have a lot of good information on this topic.
7-46 Chemical Processing Reactors and Reactions
7-47 Physical Operations in Chemical Processing Plants
7-14 Fire Protection for Chemical Plants
3-26 Fire Protection Water Demand for Nonstorage Sprinklered Properties
7-42 Evaluating Vapor Cloud Explosions Using A Flame Acceleration Method
RE: Max firewater demand scenario
“To minimum firewater supply capacity, the governing fire water rate for the Project has been determined by splitting the area in subdivisions for which the maximum extent of any single fire has been established. Each subdivision is separated from all others by a minimum of 15m clear space.”
Can anyone provide me reference or concept for “15m clear space”. How to determine a typical clear space if 15m is not suitable.