Corrosion exists in almost every fire sprinkler system installed. Some systems are always filled with water – wet pipe systems. Some systems have air in the pipes until the system is called to fill with water – dry pipe and pre-action systems. Both wet and dry systems have corrosion issues, but they are dramatically worse in dry systems.
The jet suddenly dips. Ding! The little seatbelt light comes on. The flight attendant’s voice lilts, “The Captain has turned on the fasten seat belts sign….” Rough flights, we’ve all been there. It’s a relief to be on the ground after one of those. Any landing that doesn’t end in a massive fireball always makes me think about how happy I am to have a good pilot at the yoke.
The ability for the gaseous agent to be retained in the protected room for an extended period of time is critical to the performance of any total flooding clean agent fire extinguishing system. NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems, requires that a minimum concentration of 85% of the adjusted minimum design concentration be held at the highest level of combustibles for a minimum period of 10 minutes. Those installing these systems are required to perform a Room Integrity Fan Test to assure the protected room will hold the agent for the required period of time.