In order to ensure the quality of pressure cooker products, the state has implemented a licensing system for pressure cooker products, and in 1992 and 1994, new mandatory standards for aluminum pressure cookers and stainless steel pressure cookers were formulated respectively. These two national standards mainly specify the four major performances of nominal working pressure, safety pressure, failure pressure and safety of opening and closing. In addition, the national standard also specifies the sealing performance, anti blocking safety and hygiene requirements of pressure cookers.