When does the fuel recirculation stop?

Fuel recirculation in the A320 aircraft occurs to ensure that the fuel remains at a suitable temperature and is adequately distributed throughout the tanks. The correct answer, which states that recirculation stops when the wing tank pumps are off, highlights an important operational aspect of the fuel management system.

When the wing tank pumps are deactivated, the circulation of fuel to and from those tanks ceases. This is crucial because the pumps are responsible for pulling fuel from the tanks for engine use or for maintaining the selected fuel distribution. When they are turned off, the system prioritizes managing fuel flow differently, leading to a halt in recirculation activities related to those specific tanks.

In the context of the other options, recirculation approaches would not inherently be dependent solely on filling the center tank, pressure thresholds, or fuel quantity reaching a specific level. For example, fuel management considerations may involve operational safety alongside system efficiencies. Thus, the operation of the pumps is a definitive factor in determining whether recirculation is actively occurring or not.