Self-operated flow control valve can only be applied to constant flow of quality control system is not suitable for variable flow operation mode reasons: 1, will have a dynamic hydraulic imbalance. When the system takes the heat source as an active variable flow control, or who through other means to reduce the flow of the system, the pressure on the pipe network will be reduced, the heat network due to the pressure becomes smaller, the proximal user self-operated flow control valve automatic valve The core will open large, to maintain the original flow constant. Due to the special structure of the flow valve, the change of the flow rate causes the characteristic resistance value S of the pipe section to change, and the total characteristic resistance of the network also changes. The distribution proportion of the total flow in each pipe section also changes correspondingly. Near-end and far-end users can not change in proportion to the total traffic. The change of traffic is only the change of traffic of the remote user. This will inevitably result in the thermal network dynamic imbalance, far-end users reach the heat requirements. 2, when the user as required to independently adjust the indoor temperature, self-flow control valve, valve users need to increase the flow, due to the limitations of self-flow control valve, the flow increase; when the valve after the user needs to reduce traffic, the user Will interfere with each other, self-operated flow control valve has become only useless pump power consumption valve. 3, need to increase circulating water flow increase can not go up. Circulating pumps reduce the outdoor climate, the need to increase the amount of circulating water, the user flow due to self-flow control valve control, so that users can not increase traffic. Therefore, neither the user-based variable flow heat network or heat source-based heat flow can not be applied to the self-flow control valve. Self-flow control valve is only suitable for constant flow of mass adjustment system. At present, many heating companies choose to convert frequency, multi-pump, less pump, pump, pump to achieve variable flow operation, heat network hydraulic balance selection of self-flow control valve is wrong. Hot network with self-operated flow control valve can not be operated in variable flow mode. More Keyword Search: Control Valve