Function of safety valve: During cooking, the pressure in the pot is too high because the exhaust pipe of the pressure limiting valve is blocked. At this time, the pressure is discharged through the safety valve to ensure the safety of the pressure cooker.
Extended data:
Principles and diagrams
The heavy hammer is also used, except that the heavy hammer is hung on the crossbar, the fulcrum of the rod is at the far left, and the exhaust hole of the boiler is in the middle. When the pressure is too high, the steam will jack up the crossbar together with the heavy hammer, and the exhaust pressure in the boiler will temporarily drop. And the limit pressure can be changed by adjusting the distance between the weight and the left end.
Only safety valves and pressure-bearing equipment are not absolutely safe. In order to be sure, people adopt double insurance. Usually, safety meters are also installed on pressure equipment. It is made of fusible metal sheet.
When the safety valve fails due to failure, excessive pressure will flush the safety disc to prevent accidents. If the water in the pot is evaporated, the temperature in the pot will rise, which will melt the metal sheet and play a safe role. In industrial production, many pressure vessels are equipped with explosion-proof discs, which are similar to the safety discs on pressure cookers.
When the pressure exceeds a certain value, the bursting disc will self-destruct to ensure the safety of the container. The safety valve is a reusable device, and it will work whenever the pressure exceeds a certain value. When the pressure drops, the safety valve resets. However, the safety disk and explosion-proof disk will be damaged after work and need to be replaced with new ones.
Baidu encyclopedia-pressure cooker safety valve