Methods to improve the service life of control valve

Methods to improve the service life of control valve

Extended life method for large opening operation

Let the control valve work at the maximum opening as much as possible at the beginning, such as 90%. Thus, cavitation, erosion and other damages occur on the valve core head.

With the destruction of the valve element and the increase of the flow, the corresponding valve shall be closed a little more. In this way, the valve element will be continuously destroyed and gradually closed, so that the whole valve element can be fully utilized until the root and sealing surface of the valve element are damaged and can not be used.

At the same time, the throttle clearance is large and the erosion is weakened when the valve is operated with a large opening, which increases the service life by more than 1-5 times than when the valve is operated with a middle opening and a small opening at the beginning. If this method is adopted in a chemical plant, the service life of the valve is increased by 2 times.

Method of reducing s, increasing working opening and improving service life

Reduce s, that is, increase the loss of the system except for the control valve, so as to reduce the pressure drop distributed to the valve. In order to ensure that the flow passes through the control valve, the opening of the control valve must be increased. At the same time, the pressure drop on the valve decreases, so as to reduce cavitation and erosion.

Specific measures include:

Orifice plate is set behind the valve to throttle the consumption pressure drop;

Close the manual valve connected in series on the pipeline until the regulating valve obtains a better working opening.

It is very simple, convenient and effective to use this method when the valve is at small opening at the beginning.

Method of increasing throttle passage and improving service life

The simplest way to increase the throttle passage is to thicken the valve seat to make the valve seat hole grow and form a longer throttle passage.

On the one hand, it can delay the sudden expansion after the flow closing type throttling, and play the role of transferring the damage position and keeping it away from the sealing surface; On the other hand, it increases throttling resistance, reduces pressure recovery and reduces cavitation.

Some design the valve seat hole into a step type and a wave type in order to increase resistance and weaken cavitation. This method is often used on the high-pressure valve in the imported device and when the old valve is improved, and it is also very effective.

Method of reducing stroke to improve diaphragm life

For the two position regulating valve, when the action frequency is very frequent, the diaphragm will break quickly in the process of folding up and down, and the damage position is usually at the circumference of the tray.

The simplest and most effective way to improve the life of the diaphragm is to reduce the stroke. The reduced stroke value is 1 / 4 dg. For example, the standard stroke of dgl25 valve is 60mm, which can be reduced to 30mm, which is 50% shorter.