The reasons and solutions for the poor sealing performance of electric single-seat regulating valve

As the core component of industrial automation control system, the stability and reliability of electric single-seat regulator has a direct impact on the safety and efficiency of the entire production process. At present, with the continuous improvement of the level of science and technology, various new materials and new processes are widely used in the field of regulating valves. Among the many performance indicators of the regulating valve, the sealing performance is particularly important, because it directly affects the leakage, control accuracy and service life of the valve. Due to the poor working environment of the electric single-seat regulating valve, it is easy to leak failure, which will cause safety accidents in serious cases, and then threaten the safety of people's lives and property. Therefore, it is of great significance to conduct in-depth research on the reasons for the poor sealing performance of the electric single-seat regulating valve and put forward effective solutions to ensure the smooth progress of industrial production.

Reasons for wear of sealing surface of electric single-seat regulating valve
1. Media erosion and particle wear
In the process of fluid transportation, solid particles or high-speed flowing fluids in the medium may cause erosion and wear on the sealing surface of the regulator, resulting in reduced sealing performance.
2. Mechanical fatigue caused by frequent opening and closing
In the frequent opening and closing process of the electric single-seat regulator, the sealing surface will be subjected to periodic mechanical stress, which is easy to cause mechanical fatigue over a long period of time, resulting in reduced sealing performance.
3. Sealing surface material does not match or quality problems
If the material of the sealing surface does not match the characteristics of the medium, or the sealing surface material itself has quality problems (such as insufficient hardness, poor toughness, etc.), it will accelerate the wear and damage of the sealing surface.
4. Errors caused by improper installation or long-term maintenance
Deviation in the installation process or long-term lack of necessary maintenance may lead to misalignment and loosening of the sealing surface of the regulator, which will affect its sealing performance.

How to test and evaluate the sealing performance of electric single-seat regulator
1. Leak test method
The common leak detection methods mainly include bubble detection and pressure drop detection. The bubble test method refers to the injection of liquid into a sealed container. When the measured fluid flows through the sealed container, the liquid will expand or contract, causing the liquid level to drop. Bubble testing evaluates leakage by applying specific pressure to the sealing surface and then observing whether bubbles appear. The purpose of the pressure attenuation test is to assess the severity of the leak by observing the pressure fluctuation in the sealed cavity.
2. Application of online monitoring technology
With the development of sensor technology, on-line monitoring technology is used more and more to evaluate the sealing performance of electric single-seat regulator. This paper introduces some commonly used valve leakage detection methods, and makes a comparative analysis and evaluation of them. This technology has the ability to detect valve leakage in real time, thus providing a scientific basis for the rapid implementation of maintenance programs.
3. The importance of regular inspection and maintenance plans
In order to ensure the sealing performance of the electric single-seat regulator, it is essential to develop and implement a regular inspection and maintenance program. Based on the use and maintenance experience of the valve in a nuclear power plant, this paper analyzes the main factors and related requirements affecting the tightness of the electric single-seat valve, and introduces the inspection contents, methods and matters needing attention. Through periodic inspections, we are able to identify and solve possible sealing problems in a timely manner, thereby avoiding further deterioration of the problem.
4. Performance evaluation criteria and indicators
In order to objectively evaluate the sealing performance of electric single-seat regulator, it is very important to establish clear performance evaluation criteria and indicators. In view of the practical problems existing in the operation of electric single-seat regulating valve, the corresponding performance evaluation method and performance index requirements are put forward, including sealing life and sealing, leakage and friction loss, flow characteristics and so on. These suggested standards and indicators should include leakage, sealing surface wear level and other dimensions.
The impact of medium corrosion on the sealing performance of electric single-seat regulating valve and countermeasures
1. Corrosion characteristics of different media to sealing materials
Different media have different corrosion characteristics for sealing materials. Therefore, when selecting sealing materials, the corrosion properties of the medium must be fully considered to ensure that the selected material has good corrosion resistance.
2. Application of anti-corrosion coating and surface treatment technology
The corrosion resistance of electric single-seat regulating valve can be effectively improved by applying anticorrosive coating on sealing surface or using special surface treatment technology. These coatings and technologies can form a protective film to prevent direct contact between the medium and the sealing surface, thereby slowing the rate of corrosion.
3. Choose a sealing material with stronger corrosion resistance
For more corrosive media, sealing materials with stronger corrosion resistance should be preferred, such as stainless steel, titanium alloy, etc. These materials have higher corrosion resistance and are better able to adapt to harsh working environments.
4. Media pretreatment and filtration to reduce corrosion factors
Pretreatment and filtration of media are also effective means to reduce corrosion factors. By removing harmful substances such as solid particles and chloride ions in the medium, the corrosive effect of the medium on the sealing surface can be reduced and the service life of the regulator can be extended.
How to correctly install and maintain to improve the sealing effect of the electric single-seat regulator
1. Preparations and precautions before installation
Before installing the electric single-seat regulating valve, the structural characteristics and use requirements of the valve should be fully understood to ensure that the installation environment meets the regulations. At the same time, it is also necessary to carry out the necessary inspection and cleaning of the valve to avoid impurities and dirt affecting the sealing performance.
2. Alignment and fastening requirements during installation
During the installation process, it should be ensured that the centering accuracy and fastening strength of the valve meet the requirements. Insufficient centering accuracy or too much tightening strength may lead to deviation or damage of the sealing surface, which will affect the sealing effect.
3. Daily maintenance and maintenance process
The development and implementation of daily maintenance and maintenance procedures is the key to ensure the sealing performance of electric single-seat regulator. This includes regular valve cleaning, inspection of sealing surface wear, replacement of wearing parts and other steps.
4. Suggestions for regular replacement of wearing parts and seals
Wearing parts and seals are easily worn parts in electric single-seat regulating valves. In order to ensure the sealing performance of the valve, these parts should be replaced regularly to avoid leakage problems caused by wear.
Electric single-seat control valve sealing material selection principles and replacement recommendations
1. Consider the selection of sealing materials
When selecting the sealing material of the electric single-seat regulating valve, it is necessary to deeply consider the characteristics of the medium, temperature and pressure and other factors. At the same time, the sealing structure and processing technology must also be considered. The performance and service life of sealing materials will be directly affected by these factors.
2. Development trend and application of new sealing materials
With the continuous progress in the field of materials science, electric single-seat regulator began to widely use more innovative sealing materials. At present, there have been some newly developed sealing materials in foreign countries to enter the market, such as metal matrix composite materials, ceramic base alloys and so on. These materials have improved resistance to corrosion, wear and high temperatures, making them more adaptable to a variety of complex operating environments.
3. Timing and steps of sealing material replacement
Once signs of wear, aging or damage to the sealing material are detected, replacement measures should be taken immediately. The newly installed seals should be tested and repaired regularly. During the process of replacing the sealing material, the operating procedures must be strictly followed to ensure that the replaced sealing material can show excellent sealing performance.
4. Verify and adjust the performance after replacement
After replacing the sealing material, it is necessary to fully verify and fine-tune the sealing performance of the electric single-seat regulator. This paper introduces a test device and test process suitable for the sealing test of electric single-seat regulating valve. We use leak detection and other means to ensure that the valve meets the established sealing standards, and adjust and improve it according to the specific situation.

There are many reasons for the poor sealing performance of electric single-seat regulating valves, including media erosion, frequent opening and closing, material mismatch, improper installation and media corrosion. In practical applications, electric single-seat regulating valves often leak, which seriously affects normal production. In order to ensure that the valve can work stably and extend its service life, we must adopt strong solutions and prevention measures for these problems. Based on the factors affecting its sealing performance, this paper analyzes the common leakage forms and their mechanisms of electric single-seat regulating valves, and puts forward the corresponding solutions and preventive measures. By carefully selecting the appropriate sealing material, strengthening the daily maintenance and maintenance, and regularly testing and evaluating the sealing performance, the sealing performance and service life of the electric single-seat regulating valve can be significantly improved. This paper mainly analyzes and discusses how to improve the tightness of electric single-seat regulating valve from the above aspects. At the same time, with the continuous progress of new sealing materials and technologies, the sealing performance of electric single-seat regulating valves is expected to be further enhanced and improved in the future.
References
[1] Common Structural Errors of straight-through Single-seat Regulating Valves
[2] Single seat control valve material selection Guide
[3] Prevention and Control of Quality Problems in Quality Management
[4] "The relationship between valve Selection and automatic control system performance"
Appendix
Interpretation of relevant terms

• Electric single-seat regulating valve: a valve that uses an electric actuator to drive the spool for flow regulation.
• Sealing performance: refers to the ability of the valve to prevent medium leakage when it is closed.
• Medium flushing: refers to the medium in the flow process of the valve sealing surface caused by the flushing effect.