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Sprinkler and Firehose Minimum Pressure Question (?)

Question asked by fawzan58 on Jul 20, 2016
Latest reply on Jul 24, 2016 by psmith

I am looking at a building with 14 floors, plus a basement, a mezzanine, and a rooftop. Sprinkler system installed in accordance with NFPA 13, with 100-110 sprinkler heads in each floor. As I have mentioned the distribution of the sprinklers in respect to size and spacing are all in accordance with NFPA 13, and all the pipes are steel.

A firewater pump and a jocky pump have been installed. These serve both the sprinkler system and the fire hoses; there are two fire hoses in each floor with 30m in length and 1-inch in diameter.


The specifications of the firewater pump are:

  • - AURORA model 495
  • - Horizontal
  • - Flow rate of 1000 GPM
  • - Pressure 175 psi (12.1 bar)
  • - Speed 3500 RPM
  • - Motor power 150 HP
  • - Electrical 380v / 3ph / 60 Hz


The jocky pump is the same model with the following specifications:

  • - AURORA model 495
  • - Flow rate of 20 GPM
  • - Head Pressure 225 psi (12.1 bar)
  • - Speed 500 RPM
  • - Motor power 7.5 HP


The main Riser Line is 6 inches feeding both the sprinklers and fire hoses. May I ask your assistant of the required minimum pressure and flow rate for the sprinkler heads and the fire hose. Please direct me to calculate, if needed, or kindly provide me of the required minimum outcome pressure and flow rate for these pumps from the provided information to have adequate pressure for each floor. I have consulted NFPA 20, NFPA 22, NFPA 14, NFPA 5000, and NFPA 13.

Again, I extend me deepest appreciation for giving my question your kind attention.


Many thanks,

Abdullah Alfawzan