How to extend the life of the regulating valve

Simply let the control valve work at the maximum opening degree, such as 90%, from the beginning. The maximum opening will cause corrosion damage to occur on the head of the valve core, such as cavitation, erosion and other damages occur on the head of the valve core. When the valve core is damaged, the flow of the medium will increase, and then gradually reduce the opening of the valve, so as to continue to destroy and gradually close, so that the entire valve core can be fully utilized until the root of the valve core and the sealing surface are damaged and cannot be used. until. At the same time, the throttling gap is large and the erosion is weakened, which increases the service life by more than 1 to 5 times compared with the valve working at normal way. In actual use, this method can prolong the life of the valve by 2 times.

2. Reduce the pressure difference distribution ratio S (the ratio of the pressure difference at both ends of the regulating valve to the system pressure drop), increase the working opening and prolong the life.

Reducing the S value means increasing the loss of the system except for the regulating valve and reducing the pressure drop distributed to the valve. In order to ensure that the flow passes through the regulating valve, the opening of the regulating valve must be increased. The cavitation and erosion are also weakened. The specific methods are as follows: setting an orifice plate behind the valve to throttle the pressure drop; closing the manual valve in series on the pipeline until the regulating valve obtains an ideal working opening. It is very simple, convenient and effective to use this method when the large-diameter valve is initially selected for small opening.

3. Reduce the caliber and increase the working opening to prolong the life method

By reducing the diameter of the valve to increase the working opening, the specific method is to replace a valve with a smaller diameter, such as DN32 to DN25; if the valve body does not change, replace the valve core valve seat with a small valve seat diameter, such as During the overhaul of a chemical industry, the throttling part dg10mm was replaced with dg8mm, and the service life was doubled.

4. Transfer the damaged position to prolong the life method

Move the severely damaged place to a secondary position to protect the sealing surface and throttling surface of the valve core and seat.