Ways To Improve The Service Life Of Control Valves（Regulating Valves）--- I

Ways to improve the service life of control valves（Regulating Valves）--- I

01. Large opening work can prolong service life of control valves.

Let the regulating valve work as far as possible from the beginning, such as 90%. In this way, damages such as cavitation and erosion occur on the head of the valve core.

As the spool is destroyed and the flow increases, the corresponding valve is closed again. This will continue to break and gradually close, so that the entire spool is fully utilized until the root and sealing surface of the spool are damaged and cannot be used.

At the same time, the large opening has a large throttle clearance and weakened erosion, which can increase the life of the valve by more than 1 to 5 times compared with the initial operation of the valve at the middle and small openings. If a chemical plant adopts this method, the service life of the valve is increased by 2 times.

02. Reduce pressure drop, increase working opening and increase lifespan

Reduce the pressure drop, that is, increase the system loss except for the regulating valve, and reduce the pressure drop distributed to the valve. In order to ensure the flow through the regulating valve, the opening of the regulating valve must be increased. At the same time, the pressure drop on the valve is reduced. The cavitation and erosion are also weakened.

The specific methods are as follows: install orifice throttling after the valve to consume pressure drop; close the manual valve in series on the pipeline until the regulating valve obtains a more ideal working opening. It is very simple, convenient and effective to use this method when the valve is selected at a small opening at the beginning.

03. Reducing the diameter and increasing the working opening to increase the lifespan

Increase the working opening by reducing the valve diameter.

The specific methods are: change a valve with a smaller diameter, such as DN32 to DN25; the valve body does not change, replace the valve core valve seat with a small valve seat diameter. For example, when a chemical plant is overhauled, the throttling piece dgl0 is replaced with dg8, and the service life is doubled.

04. The method of moving the damage position to increase the lifespan

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

05. Increase the throttling channel to increase the lifespan method

The simplest way to increase the throttling passage is to thicken the valve seat, so that the seat hole will grow to form a longer throttling passage.

On the one hand, the sudden expansion after the flow closed throttling can be delayed, and the damage position can be shifted away from the sealing surface; on the other hand, the throttling resistance is increased, the pressure recovery degree is reduced, and the steam Eclipse weakened.

Some design the valve seat hole to be stepped or waved to increase resistance and weaken cavitation. This method is often used when introducing high-pressure valves in the device and when improving old valves, and it is also very effective.