Foam Suppression Systems for Diesel Generator

Discussion created by msamadhin on Nov 2, 2016

I have been trying to get the experts at NFPA to answer a few simple questions, but keep getting referred back to standards which offer little beneficial information.  Please can someone with any knowledge of diesel generators and diesel storage systems give me some advice.  Here are the questions:


  1. NFPA 16 requires that foam suppressions systems be housed in a separate room from the room being protected.
  2. I have a large diesel generator installation (almost 4 MW) in a development.  I am storing the main bulk fuel (which is larger than 660 usgal) in a separate room with a day tank in the generator room.
  3. The fuel is Diesel.
  4. Questions:
    1. Can AFFF be used as a Foam/water system to protect these rooms - both the tank room and the generator room?
    2. Can I put the foam system within the generator room?
    3. Can I put the foam system within the bulk fuel storage room?
    4. How do you calculate the application area for the sizing of the AFFF system?  Is this the entire floor area of the room or is it the area where diesel is allowed to pond in the event of a fire, meaning, can I subtract the footprint of the diesel generators from the overall room footprint?  Can I subtract the tank foot print from the room area for the tank room?
    5. What is the application density - some references indicate 0.1 usgpm/sq ft whereas one of the standards indicate a minimum of 0.16 usgpm/sq ft?
    6. NFPA 110 indicates that a Pre-action system be used.  Is this only for a water based system or should the foam system also be preaction?