I worked in a kitchen store for a while but that was in the early 80s, they used to have people come in and demonstrate small appliances so they could sell more. One day a man came to do a pressure cooker demonstration and show everyone how safe the new models were then. He did this whole talk about the safety features and how they couldn’t explode. Then he would remove the top jiggler at pressure without releasing any pressure to show how safe they were! The crowd would get back as if they were ready to flee! It made a noise between a whistle and a moan but never even popped the rubber safety plug. He would keep right on talking. We sold a lot of pressure cookers after that demo.
One of my daughters left the kitchen while cooking beans in one of those safe pressure cookers and it got so much pressure it started screaming out the top, the jiggler stayed on. I ran to the stove and turned off the heat but that thing shot bean juice all over my kitchen! It didn’t explode but literally sprayed bean juice like a paint sprayer. It did not blow out the safety plug! Cleaned bean juice oh my what a mess and it would come back. I painted and still it gradually comes back (I should have primered it!) and I have to repaint the kitchen ceiling every couple of years to this day.
I didn’t know that could still happen. The classic story is of ceiling decorated with food.