In 1921, Chetwood Smith had this to say in the American Water Works Association Journal, “I have seen over 35 explosions from overheating water. The force of these explosions — no one can realize who has not seen them. A 30-gallon range boiler raised to a temperature of 290° F has as much energy as 1.5 pounds of nitroglycerine when the explosion occurs, and I think very few people realize the force of the energy they are storing up.”
In the early 1900s, water heaters and boilers were exploding on a weekly basis, often taking lives and causing extensive property damage. Just one year later, Smith patented the first temperature and pressure relief valve: https://bit.ly/3rTJ6El.