On fuel tankers, chemical tankers, and some dry cargo ships, Foam Suppression Systems are the most effective method against Class B (flammable liquid) fires. Foam covers the burning liquid, prevents vapor release, cuts off oxygen contact, and cools the liquid.
Low and High Expansion Foams
Foam systems in ship applications are classified according to expansion ratios:
- Low Expansion Foam: Generally used in deck foam systems of tankers. It covers the burning surface with a dense and heavy foam layer without being affected by wind. Applied with foam monitors or applicators.
- High Expansion Foam: Generally used for total flooding of enclosed volumes such as engine rooms, cargo holds, or Ro-Ro decks. It produces a very large volume of foam with a small amount of water and rapidly fills the environment, suffocating the fire.
System Components and Maintenance
A foam system basically consists of a foam concentrate tank, proportioner, water pump, and discharge nozzles. The quality of foam concentrate can deteriorate over time; therefore, according to IMO rules, samples must be taken periodically and subjected to laboratory testing (foam life, expansion ratio, sediment, etc.).
Teotek Marine provides end-to-end services from the design of foam systems on your ship to foam liquid supply and annual analyses. The selection of the correct foam type and proper calibration of the system makes a vital difference in the event of a fire.