Self-operated differential pressure control valve is not applicable to the heat source as the main variable flow control system, when the system takes the heat source as the main variable flow control (inverter, reduce the number of circulating pump, change the smaller circulating pump, etc.) to reduce the system flow, the tube Network pressure will be reduced, heat network near the end of the user due to the pressure becomes smaller, differential pressure valve will automatically open the valve spool to maintain the original pressure is constant, the flow changes are only remote users, remote users serious lack of traffic . Near-end users and remote users can not be the same as the total flow changes and can not maintain the balance of hydraulic conditions, heat network dynamic hydrodynamic imbalance. On the contrary, the circulating pump reduces the outdoor temperature, the need to increase the circulating water, the user does not change the valve opening, the user pressure differential pressure control valve due to self-control, so that users can not increase traffic. Therefore, self-operated pressure control valve is not applicable to the heat source for the variable flow control system. Self-operated pressure control valve for users to take the initiative to change the flow of heat network operation. Heat network flow changes depending on the user's heat requirements, heat source changes and regulation of the user-based, the user needs how much heat, the heat source to provide how much calories. When the user indoor temperature reaches the design value, the indoor thermostat automatically shut down small, the user back pressure decreases, the differential pressure increases, the differential pressure valve will work with the thermostatic valve, automatically close the valve port to constant user pressure. Then the inverter based on perceived user needs, automatic adjustment frequency pump operation, so as to achieve variable flow energy-saving operation. Users to take the initiative to change the flow of a prerequisite, the user must install thermostatic valves and other self-control device, heat inlet to install self-contained pressure control valve can be achieved. Indoor installation of thermostatic valve, heat inlet to install self-contained pressure control valve, heat pump circulating pump frequency control. This user-driven variable flow variable flow mode of operation is the future direction of development, but also the most energy-efficient. This article Keywords: control valve