Why can Dongling portable electric water cup be sealed to boil water? How did it happen?

Dongling portable electric water cup can really close the seal and boil water. Let me explain the principle. As we all know, when water boils in a meeting, water vapor will produce great pressure, and Watt's steam engine was invented in this way. In order to close the lid and seal the water, there must be technology to relieve the pressure. Dongling portable electric water cup has NTC temperature control protection, and the water will jump immediately when it is boiled to prevent the risk caused by continuous boiling. Secondly, the lid of Dongling drinking cup has a built-in breathable film, which automatically releases air pressure upward when boiling water. The inner wall of the cover is provided with a pressure relief valve port from which the air pressure is discharged. This way, the lid is closed and sealed to boil water. The advantage is that it does not need special care and is not afraid of falling ash and bacteria, which many kettles on the market can't do. In addition, Dongling portable electric water cup can be kept warm for 8 hours without electricity, and it is very practical to switch three temperature settings of 45℃/55℃/ 100℃ with one key. Only a cup the size of a mineral water bottle is also very portable.