What is used to prevent negative pressure or overpressurization in the event of an outflow valve failure?

The use of pressure relief valves is crucial in maintaining safe cabin pressure levels, particularly in the event of an outflow valve failure. These valves are designed to automatically open and vent excess pressure from the cabin when it exceeds a predetermined limit. This ensures that the cabin does not experience overpressurization, which could lead to structural damage or compromised safety of the aircraft.

In the scenario where the outflow valve fails, pressure relief valves act as a safety mechanism. They help maintain the cabin pressure within safe operational limits, thereby preventing both negative pressure situations and excessive pressures that could arise from mechanical failures or malfunctions within the pressurization system. This is essential for the safety and comfort of both the crew and any passengers onboard.

While safety valve systems, automatic cabin temperature regulators, and manual cabin pressure controllers play important roles in aircraft systems, they do not specifically address the direct issue of preventing negative pressure or dealing with overpressurization consequences in the way that pressure relief valves do.