Abstract: The use of flexible foam material to provide ignition mitigation in fuel tanks is described. In one example, a system for ignition mitigation includes a number of foam blocks, wherein each foam block is pre-cut from a flexible foam material. Each foam block can have a unique profile corresponding to inner surfaces of a fuel tank at a particular sector within a compartment of the fuel tank. In other aspects, one or more of the foam blocks can include one or more upper cutouts to provide clearance for upper stiffeners in the fuel tank, one or more lower cutouts to provide clearance for lower stiffeners in the fuel tank, and one or more arcuate cutouts to provide clearance for a tank fuel pump. The foam blocks can be arranged in a stack corresponding to a sequential installation at respective sectors within the compartment of the fuel tank.

Abstract: A method utilizing quantities of flexible foam material inserted into a fuel tank, thereby providing ignition mitigation and minimizing the risk of explosion in the tank. The foam material is sculpted into a few, or a substantial quantity of foam blocks. In large-scale installations, the blocks are labeled according to exact placement within a stacking pattern that replicates the tank interior. The blocks are inserted by technicians through existing access ports until the tank is filled, excepting minimal planned void spaces. The foam material establishes ignition mitigation by acting as an ignition blocker, mechanically interfering with the compression wave created by a flame front in an explosion, and changing the vaporous mixture-above the fuel level in the tank. Upon completion of foam insertion, the fuel tank is filled with purging fluid, drained through a filter until no debris is found, and a new maximum fuel quantity recalibrated.