I made an apple peel itself

Go to https://brilliant.org/StuffMadeHere/ try the tutor for free and get 20% off your annual premium subscription! SAFETY NOTICE This video depicts an experimental system involving high-pressure steam. Boilers and pressure vessels contain substantial stored energy and can cause severe injury or death if they fail or are operated improperly. Their construction and use may also be governed by engineering codes, inspection requirements, permits, and other regulations that vary by jurisdiction and application. This video is a record of an experiment, not a construction guide. Do not copy, reproduce, or operate equipment based on what is shown here. A hydrostatic test, a pressure relief valve, or an engineering background does not by itself make a homemade pressure system safe. Anyone working with pressurized steam should consult qualified pressure-equipment professionals and the applicable authorities before building or operating anything similar. SOURCES: Belleville washers: https://en.wikipedia.org/wiki/Belleville_washer