Let’s talk about the principle first: When there is soup in your pot, the pot is heated because the liquid turns into a gas when it evaporates, and the density of the gas is very small compared to water. Therefore, according to the conservation of mass and M=p*V (mass is equal to density times volume), it can be deduced that the volume of the gas will increase rapidly. At this time, because the pot is sealed, the volume cannot increase and begins to be compressed, so the air pressure in the pot is higher than the normal pressure (one atmosphere). The boiling point of water is related to the air pressure. The greater the air pressure, the higher the boiling point, and the lower the air pressure, the lower the boiling point. Therefore, the temperature of the soup in your pot is higher than 100 degrees (considering water, salt water can lower the boiling point. As for pepper aniseed and the like, I have not studied it, and it may have an impact). Therefore, it is easier to cook things using a pressure cooker.

The pressure cooker has a pressure regulating valve. When the air pressure is too high, there is a risk of explosion. The left and right sides of the high-pressure valve release a part of the gas to achieve the purpose of pressure relief when the air pressure is too high.

The only difference between a low-pressure cooker and a high-pressure cooker is that the weight of the pressure relief valves between them is different, so the gas pressure can be maintained at two different pressures, so the boiling point of water can be controlled.

The following is an excerpt of a low-pressure cooker introduction:

It can accurately control the steam pressure in the pot to work at 5kpa. After boiling, it only needs a small amount of heat energy to maintain the pot. 103℃, boiling state, the energy saving effect is very significant.

In fact, both principles are the same