Control Valve

Common Questions Related to the Control Valve

It is obvious that the valve industry is on its way to prosperity. And there is a wide range of types with various sizes and specifications to achieve a variety of demands. The control valve, as one of the particular kinds, has been widely used in many fields, affecting as an effective device to regular the flow. And it is certain that the device would come across some problems during its operating in terms of some specific types. Now, some common problems and their solutions related to the flow control valve are introduced in the following.

1) Why it is easy to oscillate for the two-seat valve with a small opening?

Generally speaking, the valve would be in good stability as the medium employed in the single-core belongs to the open-type flow. However, if the medium belongs to the closed-type flow, the stability of the valve would be greatly influenced. And for the two-seat valve, there are two spool valve seats. One is open and the other is closed. Thus, the closed one would greatly be influenced, not to say under the status of the small opening. As a result, it is unwise to employ the two-seat valve with a small opening.

2) Why not use a double seal valve to affect as a cut-off valve?

The double seal valve is popular resulting from the good case for its structure, allowing a large pressure difference. And the shortage is that the two sealing faces can not be in good contact, leading to a large leakage. Thus, it is unwise to regard it as a cut-off valve.

3) Why does it better to use a hard seal in the shut-off valve?

It should be mentioned that the shut-off valve requires that the lower leakage, the better. And soft-sealing is definitely with the least leakage which would be the best choice for the shut-off valve. However, the characteristics of poor reliability and wearing resistance greatly reduce its advantages. Thus, it is necessary to use hard sealing. Then, a material like an alloy with good wearing resistance would be a better choice.

Above all, there is something that needs to be kept in mind. Compared to the calculation, the selection should be much more important and much more complex, because the calculation is a simple formula, whose accuracy is closely related to the accuracy of the given parameters. However, the content of the selection is mass which would lead to inappropriate selection easily. If it does so, the waste of human, material, and financial resources would be caused, together with the dis-satisfactory of the reliability, operating life, and running quality.