New fire system tie-in to existing plant fire water tank

[fdomin]

Hi all,

In a project we are dealing with, our client wants to eliminate the fire water tank from a future natural gas compressor station. They are planning to use the existing gas plant fire water tank, located 900 meters away and 20 meters below the compressor station grade. A new 14" pipe is required to deliver the 2000 gpm to the required 150 psig at the station.
The current tank volume is adequate for the new fire scenario and independent new fire water and jockey pumps would be installed, making a tie-in to the existing fire water pumps suction header.
Does NFPA allow a system like this one? I have been reading NFPA 20, 22 and 24 but cannot find any objection, but feedback from experienced fire system designer would be very valuable.

Another question regarding this system is about the fire water pump controller pressure switch. We should correct the set point to take into account the hydrostatic pressure, is this possible? A pressure transmitter located at the station could be used instead?

Regards,

 

[mk3223]

It's okay to extend the existing firewater system to the new compressor station once it can supply adequate firewater flow and head. One design to consider is to ensure the firewater supply from the loop piping. The pressure control should be close to the Compressor station to ensure the head pressure of the firewater supply as needed.