What is the operation of the cabin pressure outflow valve and cabin pressure safety valve.?

Question

What is the operation of the cabin pressure outflow valve and cabin pressure safety valve.?

Answer 1

You need to be more specific in asking the question, however;

Outflow Valve is a valve that regulates the amount of air needed to be released (or on the other hand, to be kept inside) from the cabin in order to keep the cabin in a required amount of pressurization. A safeguard to protect the aircraft from being over-pressurized or under-pressurized is by employing safety valves.

When the differential pressure is too high and the outflow valve fails to rectify the situation, the safety valve opens, reducing the cabin pressure. Likewise, when on the ground, and the cabin pressure is lower then outside air pressure, the negative pressure valve will equalize the situation.