NFPA 30 Tank Separation Calculations

[jmk0407]

How does one calculate tank separation distances for groups of tanks larger than 2 tanks by 2 tanks in accordance with NFPA 30? Say if I have a grid of 3 tanks by 3 tanks, all floating roof, all with flammable liquids for the sake of this question. Is it one uniform tank distance calculated by summing every possible adjacent tank diameter combinations and dividing by 6? It seems like the number will be excessively large if I follow the methodology as described for 2 tanks by 2 tanks as explained in the NFPA 30 handbook. Thank you for your assistance.

 

[stookeyfpe]

The NFPA 30 technical committee issued a formal interpretation on this subject. See interpretation 30-08-1 to Section 22.4.2 based on the 2008 edition of the standard.

http://www.nfpa.org/Assets/files/AboutTheCodes/30/FI30-2012.pdf