What occurs to the gauge pressure in a kettle as it cools?

As a kettle cools, the temperature of the steam inside decreases, leading to a decrease in the steam pressure. When steam condenses back into water, it reduces the amount of gas in the kettle, creating a vacuum effect. This reduction in gas volume and pressure results in a situation where the pressure inside the kettle becomes lower than the atmospheric pressure outside, leading to a vacuum being formed.

This phenomenon is due to the relationship between temperature and pressure in gases, as described by the ideal gas law. When steam condenses, the volume of gas decreases, while the number of gas particles is also reduced, resulting in a lower pressure.

Understanding this process is crucial in steam equipment maintenance, as failing to account for this pressure change can lead to issues such as damage to the kettle or affecting the operation of associated equipment.