DBB plug valve is a type of Double Block and Bleed (DBB) valve that combines the features of a block valve, a bleed valve, and an isolation valve into one compact unit. DBB plug valves are commonly used in the oil and gas industry, chemical processing plants, and other applications where flow diversion and distribution is required. This type of valve is designed with a tapered plug that rotates within a cylindrical chamber. When the plug is rotated, it can be used to control the flow of fluid through the chamber. In addition, DBB plug valves also allow for the sealing of both sides of the valve, effectively blocking fluid flow in both directions. This feature makes the valve ideal for use in applications where isolation is critical, including emergency shutdown and maintenance operations.