Industries have several difficulties: fixed stationary systems and mobile systems (trucks, pickups equipped with CAFS, etc.) In both cases, the first topic to take into account would be the type of risk marked by the fuel, storage conditions, manufacturing processes, etc.
In tank storage, the following main topics have to be considered:
· if the system is sub-surface or over the fuel
· if there is a retention dike, so medium expansion foams are suggested
· if there are hydrocarbon and polar solvent tanks
Generally, if there is a mixed risk (hydrocarbons and polar solvents), a multipurpose foam (AR-AFFF or Fluorine Free) will be the right choice. The mixing ratio for the foam will be linked to the risk percentage:
· for a 90% hydrocarbon / 10% polar solvent combined risk, the right choice would be a 1x3 foam.
· for a 50% hydrocarbon / 50% polar solvent combined risk, the right choice would be a 3x3 foam.
In fixed systems, a compatibility test must be taken before filling foam tanks with different products.