Application Method of Various Regulating Valves in Air Conditioning Water System

A. Design and arrangement principle of manual balancing valve

The manual balancing valve should be installed level by level, that is, the valve should be installed on the main pipe, stand pipe and branch pipe; branch balancing valve, vertical balancing valve and main balancing valve should be installed on each parallel branch pipe at the same time.

B. Auto balancing valve

Auto balancing valve is generally used in occasions where the flow is fixed. When designing the layout, the following principles should be paid attention to: It should be installed on the end devices such as fan coil units and air handling units; if the auto balancing valve is installed at the end of the system, it doesn't need to install auto balancing valves on the branch pipe and stand pipe; auto balancing valves should be installed on freezers or boiler outlets to avoid the overflowing of these equipment.

C. Self-operated differential pressure controller

It is a proportional differential pressure controller, which has a certain proportional differential pressure range to meet the needs of variable flow; when matched with manual balancing valves, the flow rate can be set accurately while the pressure difference is stabilized.

Self-operated differential pressure controllers are usually used with manual balancing valves, and the combination is called flow/differential pressure balancing valve group or flow/differential pressure regulator combination, which is usually also known as dynamic balancing valve group or automatic differential pressure balancing valve group. It is very accurate balancing equipment classified as auto balancing valve category. When each control valve is matched with this kind of valve, the valve weight is close to 1.

The comparison of the three application modes:

In the above three applications, from the perspective of equilibrium, the self-operated differential pressure controller is better than auto balancing valve, and the auto balancing valve is better than manual balancing valve. Especially self-operated differential pressure controllers, if each control valve in the system is linked to a self-operated differential pressure controller, it will be the best solution in terms of control, because the valve weight of the control valve is close to 1; from the perspective of cost performance, auto balancing valves are the most widely used.