A comprehensive plan of attack can prevent physical and financial disaster.
There are many reasons why a fire sprinkler system fails to control a fire.
If fire water supply is not available at the minimum pressure and volume for which the system is designed, one has to hope for the best and wait for the fire department to arrive. During a field investigation of a building up for an expansion, I normally check the existing life safety systems to verify what I have to work with. Verifying fire alarm status and fire water flow data is part of that investigation.
One recent visit involved checking exterior hydrant status and taking flow data. However, the hydrant on the building fire water main seized. I checked inlet and outlet pressures to the fire pump inside the building. The static pressure was 70 psi. I then began opening valves to the exterior pump test outlet to trigger the fire pump operation. The fire pump kicked on, the pump inlet pressure gauge went to zero and the pump outlet pressure was about 10 psi.
This pump was installed to operate at a minimum inlet pressure of 20 psi with a minimum flow of at least 450 gpm. There was no way it was going to do that. I began normal shutdown and reset of the pump and valves. Alarms went off in my head about why the pressure dropped to zero.