Explanation of NFPA 12 Nozzle Codes
GSI's Tom Wysocki has served on the NFPA technical committee for carbon dioxide fire extinguishing systems since 1977. He currently serves on the NFPA GFE technical committee which writes the standards (NFPA 12, 2001, and 12A) covering various gaseous fire extinguishing agents. As a senior member of these technical committees, he regularly receives questions on these standards. One of the most common questions is "How is the definition of nozzle orifice numbers - or codes for CO2 systems - to be applied?"
There is a great deal of misunderstanding of the code method used to size nozzles for CO2 systems. Mr. Wysocki has prepared a 16 minute video presentation which explains the meaning and application of the "NFPA 12 nozzle code." To watch this free video, please click on the image below. Your speakers should be "on" with volume set appropriately.