The function is to measure and indicate the pressure in the pressure product. The pressure gauge transmits the pressure deformation to the pointer through the elastic deformation of the sensitive elements (Bourdon tube, bellows, bellows) in the watch, and then causes the pointer to rotate to display the pressure. If the pressure product does not have a pressure gauge, or the pressure gauge fails, the pressure of the pressure product cannot be expressed, thus directly endangering safety. A sensitive and accurate pressure gauge is installed on the pressure product, so that the operator can operate the pressure product correctly with the pressure gauge to ensure safe and economical operation. The pressure gauge can accurately indicate the level of steam pressure in the pressure product. The operator can adjust the heating degree of the product according to the indicated value of the pressure gauge to ensure the requirements of the gas department and the safe operation of the pressure product.