That's why it has a safety valve. And trust me it works perfectly. Actually if you have an original you. Can use the edge of a knife or spatula to carefully pull the valve out a bit as it builds pressure. Then you can get a sense of what kinds of pressure you are dealing with and hopefully feel safe that the valve works. Just he super careful and don't keep you hand close. The type of valve is patented and can only be found on the original. Copies uses a different type of valve that you cannot actuate like this.