Balanced trim control valves are usually divided into static balance valves, dynamic flow balance valves and dynamic differential pressure balance valves.
A. Static balancing valves are also called manual balancing valves, digital locking balancing valves, and butterfly balancing valves and so on. They change the opening of the valve core and seat to change the flow resistance of the valve in order to achieve the purpose of regulating the flow. Their function is to balance the flow of water according to the designed proportion, increase and decrease the branches at the same time in proportion, and still meet the current climate needs of part of the load flow. Quantity demand plays a role of heat balance.
B. Dynamic flow balance valve is also called self-operated flow control valve, self-operated balance valve, constant flow valve, automatic balance valve, etc. The self-operated flow control valve automatically changes the resistance coefficient according to the change of system working condition. Within a certain range of pressure difference, it can effectively control the flow through and maintain a constant value. That is, when the pressure difference between the front and the back of the valve increases, that the flow through the action of small automatic closure of the valve can keep the flow constant. On the contrary, when the pressure difference decreases, the valve opens automatically and the flow remains constant. However, when the pressure difference is smaller or larger than the normal working range of the valve, it can not provide additional pressure head after all. At this time, the flow of the valve to the full open or closed position is still lower or higher than the set flow.
C. Dynamic differential pressure balancing valve, also known as self-operated differential pressure control valve, differential pressure controller, voltage regulator synchronizer, differential pressure balancing valve, etc. It uses differential pressure to adjust the opening of the valve, and uses the change of pressure drop of the valve core to compensate for the change of pipeline resistance, so as to keep the differential pressure basically unchanged when the working condition changes. Its principle is within a certain flow rate range, and it can be effective. Controlling the pressure difference of the controlled system is constant, that is, when the pressure difference of the system increases, it can ensure that the pressure difference of the controlled system increases through the automatic closing action of the valve. On the contrary, when the pressure difference decreases, the valve opens automatically and the pressure difference remains constant.