YB7 series back pressure valve is also called pump protection valve, used in general control system can not be applied to the working conditions, it as a special pressure control valve, often matched with automatic recirculation, used in pump protection system. Back pressure valves are also used in a large number of other control valve systems. Back pressure valves control the upstream pressure to the pressure value set by the factory process or the pressure value required by the system, preventing vaporization and cavitation. Careful matching of the process conditions between the automatic recirculation valve and the back pressure valve ensures that the pump is optimally protected and guarantees long-term stable and safe operation of the system.