DBB valve is a special ball valve, it is composed of two balls, each ball has its own seat ring and operating mechanism. Both balls can be operated simultaneously or separately, enabling precise control of the fluid in the pipe. DBB valve is commonly used in situations where quick switching of pipe flow direction and fluid isolation. In the control of some important pipelines, the DBB valve can be used to improve the reliability and safety of the system. For example, if one valve fails, the other ball can continue to keep the pipe running properly. In addition, the DBB valve can also be used for the control of multi-fluid media, such as water, gas, liquid and steam. They are commonly used in areas such as liquid separation, water treatment, chemical processing, and oil and gas transmission. Because of its stability, durability and high control ability, the DBB valve has become one of the important tools of modern pipeline control.