[derekp7]

Pressure sensor that cuts off the electricity if pressure gets too high. No more electricity, no more heating, pressure drops. Another one I've seen on my mom's pressure cooker that she's had for probably 40 years or more, is a physical plug that will shoot out if the pressure gets too high and the release valve gets stuck. Of course, not sure what the potential damage from this plug would be (I've only ever seen it shoot into the pot when it was removed from the stove, and cooled too quickly). But better than the whole thing popping.

[akgerber]

The Instant Pot claims to have some sort of mechanism that will lower the cooking pot and break the seal in an overpressure situation: http://instantpot.us/benefits/safety-features/