Firewater System - Self contained systems

[JonnyWill]

Hi all, Application. Offshore platform.
Fire hazards in the utility areas are generally limited.. but why is it; Firewater diesel, emergency generator, and main transformer rooms .... all have there own self contained protection system , why aren't these also not connected to the main firewater system? ...
Why do we need a self contained system?, similarly in the hull.. diesel handling area... also Self contained ..

Can anyone shed some light on this area....
Thanks in advance.

 

[cdafd]

Are these systems either clean agent, water mist, dry powder or some other extinguihing system besides fire sprinkler. If so it is more than likely to protect a certain hazard with the least amount of damage if the system discharges, so you do not take that piece of machinary out for some small fire.

 

[JonnyWill]

The self contained system which we are considering is: water mist for the above mentioned equipment .... but couldn't that still be supplied from the main firewater system?

 

[ELEcontrol3e]

JonnyWill

1) To manage hazards, often compartmentilization of fire areas are used to separate fire areas. For example according to ICC codes, desinging a building with a fire wall(structural continuous, parapet, 18" above roof,etc.) will separate the structure into two different buildings, so if one building/fire area requires a sprinkler system then the other might not. Then it follows that their fire suppression systems are usually isolated as well by the same design philosophy.

2)As you probably already know. In open deluge mist system upon detection a solenoid valve on the Nitrogen system will be activated and Nitrogen will be released through the regulator which will reduce the pressure on entering the watermist valves. A flow switch turns on and activates the switch for mist. So water from an integrated system can be a problem.

3)Plus I believe there are more stringent water quality requirements on mist systems, thus again a need for isolation.

 

[JonnyWill]

thanks for your help ..... ELControl3e