Clamont
Mechanical
- Dec 10, 2012
- 40
I would like to get some answers to some very basic questions with regards to NFPA 30 and the fire fighting requirements to comply to this standard.
1. It is my understanding that to comply to this standard it more or less comes down to the type of fire protection you have in place compared to the proximity of your tank(s) to outside surroundings. In some instances if your tank(s) is far enough away from property lines or public ways then you may not require ANY fire fighting to be compliant to the standard if you are storing Class II or III products (and Class I if under 190m3 volume). I know this seems very clearly spelt out in the standard and may be incredibly obvious but I am struggling to get my head around the fact that you can have no fire fighting capability and still be compliant to an NFPA standard.
2. If you do want to comply with NFPA 30 and you require a fire fighting system the design must be in accordance with the appropriate NFPA standard which for fixed spray system is NFPA 15. In this standard it stipulates for an atmospheric storage tank that the amount of water to allow for is 10.2 L/m2/min and the maximum height between horizontal cooling rings is limited to 3.7m. If designing to this standard it often work out that the volume of the water tank is equal or larger to the volume of the product tank dependent on the duration of spray that you design to. I have never seen an atmospheric storage tank with cooling rings spaced at 3.7m from one another and also never seen a tank farm with such large water reserves. All of the tanks I have seen generally just have the one cooling ring at the top of the tank. Are these tanks basically non-compliant to NFPA or am I missing something?
3. This brings me to my 3rd question. It states in the standard the water volume requirement per m2/min however if you have multiple tanks in a tank farm must you consider the water requirement for every single tank at the same time? This would require massive amounts of water however cannot see anything to imply otherwise.
4. It also does not stipulate the length of time that the water must be applied to the shell at this rate for. I have often heard a 2 hour coverage is required however cannot find it anywhere in the standard.
I look forward to insightful answers to the above seemingly very basic questions.
1. It is my understanding that to comply to this standard it more or less comes down to the type of fire protection you have in place compared to the proximity of your tank(s) to outside surroundings. In some instances if your tank(s) is far enough away from property lines or public ways then you may not require ANY fire fighting to be compliant to the standard if you are storing Class II or III products (and Class I if under 190m3 volume). I know this seems very clearly spelt out in the standard and may be incredibly obvious but I am struggling to get my head around the fact that you can have no fire fighting capability and still be compliant to an NFPA standard.
2. If you do want to comply with NFPA 30 and you require a fire fighting system the design must be in accordance with the appropriate NFPA standard which for fixed spray system is NFPA 15. In this standard it stipulates for an atmospheric storage tank that the amount of water to allow for is 10.2 L/m2/min and the maximum height between horizontal cooling rings is limited to 3.7m. If designing to this standard it often work out that the volume of the water tank is equal or larger to the volume of the product tank dependent on the duration of spray that you design to. I have never seen an atmospheric storage tank with cooling rings spaced at 3.7m from one another and also never seen a tank farm with such large water reserves. All of the tanks I have seen generally just have the one cooling ring at the top of the tank. Are these tanks basically non-compliant to NFPA or am I missing something?
3. This brings me to my 3rd question. It states in the standard the water volume requirement per m2/min however if you have multiple tanks in a tank farm must you consider the water requirement for every single tank at the same time? This would require massive amounts of water however cannot see anything to imply otherwise.
4. It also does not stipulate the length of time that the water must be applied to the shell at this rate for. I have often heard a 2 hour coverage is required however cannot find it anywhere in the standard.
I look forward to insightful answers to the above seemingly very basic questions.