What mechanism is used to prevent a heavily loaded APU from exceeding its maximum Exhaust Gas Temperature (EGT)?

The load control valve is a critical component in managing the power output of the Auxiliary Power Unit (APU), particularly when it is heavily loaded. Its primary function is to regulate the amount of fuel delivered to the APU based on its operational conditions. When the APU experiences a heavy load that could potentially lead to an excessive increase in Exhaust Gas Temperature (EGT), the load control valve responds by limiting fuel flow.

By adjusting the fuel supply, the load control valve helps maintain the EGT within safe operational limits, preventing overheating that could cause damage to the APU. This mechanism is essential for ensuring the reliability and longevity of the APU under varying load conditions, particularly during periods of high demand when EGT is most likely to rise.

Other options, while related to the operation of the APU, do not directly regulate the EGT in the context described. For instance, the fuel control system encompasses various components involved in fuel management but specifically lacks the targeted functionality of the load control valve in EGT regulation. Temperature sensors monitor EGT but do not take action to mitigate temperature increases. The throttle limiter is more about controlling the maximum output rather than specifically addressing EGT concerns during different load scenarios.