Detail

1. Structure and performance

       The role of self-operated flow control valve is to maintain the constant flow through the valve in the case of changes in the pressure difference between the inlet and outlet of the valve, so as to maintain the constant flow of the controlled object (such as a loop, a user, a device, etc.) in series with it. Self-operated flow control valve has more names, such as self-operated flow balance valve, fixed flow valve, self-balancing valve, dynamic flow balance valve Various types of self-operated flow control valves have different structures, but their working principles are similar.

2. Structure and working principleStructurally

       The self-operated flow control valve structure speaking, is a double valve combination, that is, it is composed of a manual regulating valve group and an automatic balancing valve group, as shown in Figure 1. The function of the manual regulating valve group is to set the flow rate, and the function of the automatic balancing valve group is to maintain the constant flow rate.

       The self-operated flow control valve for the manual control valve group, the flow G=P2-P3 type, Kv is the flow coefficient of the manual control valve port, and P2-P3 is the pressure difference on both sides of the manual control valve port. The size of Kv depends on the opening, the opening is fixed, Kv is a constant, so as long as P2-P3 is unchanged, the flow G is unchanged. The constancy of P2-P3 is controlled by the automatic balancing valve group. For example, the inlet and outlet pressure difference P1-P3 increases, then the automatic balancing valve group is turned down through the action of pressure sensing film and spring, so that P1-P2 increases , so as to maintain the 1 constant of P2-P3; On the contrary, P1-P3 is reduced, and the automatic balancing valve group is expanded, so that P1-P2 is reduced and P2-P3 is maintained constant.

       Each opening of the manual control valve group corresponds to a flow rate , and the relationship between the opening and flow rate is calibrated by the test bench test, and equipped with the opening display and locking device.

3.Performance and features

       1. The flow can be set according to the design or actual requirements, which can automatically eliminate the pressure difference fluctuation of the system and keep the flow unchanged;

       2, to overcome the uneven cold and heat of the system, improve the quality of heating (cooling);

       3. Completely solve the contradiction between large pressure difference at the near end and small pressure difference at the far end;

       4, reduce the system circulation water, reduce the system resistance;

       5, reduce the design workload, do not need to carry out tedious hydraulic balance calculation of the pipe network;

       6, reduce the difficulty of network adjustment, simplify the complex network adjustment work into a simple flow distribution;

       7. Eliminate the flow redistribution work when the heat source of the multi-heat source pipe network is switched;

       8. flow display values are randomly calibrated on the test bench, flow (m3/h).

4.Technical parameters

       1.medium temperature 0-150ºC 2, working pressure difference 20-600Kpa selection 1, can be selected according to the equal diameter of the pipeline

       2. Can be selected according to the maximum flow rate and the flow range of the valve.

5.Installation and commissioning

       1. the flow direction of the medium should be consistent with the flow direction of the valve body arrow;

       2. Set the flow rate according to the demand of its series pipeline after installation;

       3, check whether the pressure difference at both ends of the valve is in the working pressure difference range;

       4.as far as possible to avoid the valve in the minimum flow state work;

       5.there is no blowdown screw on the spring cover, should be regularly blowdown.

6.Implement standard 

       CJ 179-2003 "Self-operated Flow control Valve"