NFPA 30 Minimum Sprinkler Operating Pressure for Chemical Storage Area

[az5333]

Hi everyone. I am currently performing the hydraulics calculation as per NFPA 13 and NFPA 30, as the subject wet-sprinkler system is installed in an indoor liquid chemical storage area. While looking at the notes for NFPA 30 16.5.2.9.3, it says that the "sprinkler operating gauge pressure shall be a minimum 30 psi". Now my question is that are they referring to the static pressure at the sprinkler head or the stagnation (total) pressure at the sprinkler head? This is because the stagnation pressure in my case is almost twice the static pressure at that point. Any guidance is highly appreciated!

 

[MGXFP]

Usually that means the pressure at the fire sprinkler while water is flowing. Fire sprinklers only need 7 psi to operate which is the minimum pressure.

 

[TravisMack]

30 psi is the minimum pressure at the sprinkler for your application to provide the required minimum flows per the standard governing the project. Flow will be dependent on the k-factor chosen / permitted.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, a Ferguson Enterprise

http://www.mfpdesign.com