What type of valve body provides the best regulation function?

Butterfly valves can only be used for rough adjustment! After all, the opening angle of a butterfly valve, as well as the flow rate it can handle, require complex calculations!

Butterfly valves have poor flow characteristics; they are mainly used for opening and closing, and are not suitable for use in control systems. If the flow rate and pressure are not very high, it is advisable to use a straight-stroke single-seat control valve; its diameter can be reduced to within DN400. This type of valve is designed specifically for regulating flow rates, and it offers excellent flow characteristics, which are far better than those of butterfly valves used for regulation.

I think a 600-size pipe is too large; with such a big valve, even the slightest opening or closing will result in significant changes in flow rate, making it difficult to make fine adjustments. If precise control is needed, it would be better to install a separate circuit, such as one with sizes of 108/159/219, and just add a control valve – this might be cheaper than buying a high-precision valve, and it would also yield better results

Based on your process medium, the pressures before and after the valve, as well as the maximum and minimum flow rates, find a reliable valve manufacturer such as Wu Zhong to customize the valve. Only with accurate data and a reliable manufacturer can the desired results be achieved.

Can several control valves be used in parallel to meet the flow requirement?

Control valves cannot be used with multiple valves connected in parallel, as this will severely affect the flow characteristics of the control valve and prevent it from performing its regulatory function. The diameter of the control valve should not be the same as that of the pipeline; rather, it must be determined after calculating based on the pressure and flow rate of the medium. Since the optimal operating range for control valves is 20% to 70%, if the pipe diameter is chosen too large, the control valve will operate within a narrow opening range, which significantly affects its control performance and can also cause noise.

For the question raised by the poster, you can send me the detailed parameters of the operating conditions on site; I will ask my colleagues in the technical department to calculate the CV value. If it’s possible to reduce the pipe diameter, tees can be installed at both ends of the pipe, with these tees connected to the control valve. This approach helps to reduce costs, and the flow rate can be controlled by using valves selected based on the parameters provided on site, thus meeting all the requirements. If a DN600 control valve is used, its price is relatively high, and it may not be precise enough for fine adjustments in flow rate. Specific parameters are needed: the type of medium, medium temperature, maximum flow rate, nominal flow rate, minimum flow rate, density or specific gravity, pressure before the valve, and pressure after the valve. Providing just these parameters will allow my colleagues in the technical department to calculate the CV value. If needed, you can send the parameters to my email at 2880268085@qq.com

Isn’t it common for there to be diameter changes before and after a control valve?

If the diameter of the pipe cannot be changed, is it possible to use other types of valves in series within the pipeline? In some pipelines, two valves are used in series: one is a shut-off valve that is inexpensive, and the other is a more expensive valve with regulating functions. It seems that most of what is used domestically are gate valves; there aren’t many true control valves, and their prices are quite high