In modern industrial automation systems, target flow switch As an important flow monitoring device, it is widely used in various fluid control scenarios. However, many users often overlook a key issue during use— medium cleanliness . Medium cleanliness not only directly affects the measurement accuracy of the target flow switch, but also the service life of the equipment and the stability of the system. So, what are the specific requirements for the medium cleanliness of the target flow switch? How to effectively ensure the cleanliness of the medium? This article will discuss these issues in detail.

I. Working principle of target flow switch and its relationship with medium cleanliness

The target flow switch detects the impact force of the fluid on the target plate to determine the flow rate. Its core components are the target plate and the sensor. When the fluid passes through the pipe, the target plate will be impacted by the fluid, and the sensor will convert this force signal into an electrical signal to achieve flow monitoring. medium cleanliness plays a crucial role in this process.

If the medium contains solid particles, impurities, or sediments, these substances may adhere to the surface of the target plate, causing uneven force on the target plate, thereby affecting the measurement accuracy. In addition, impurities may also block the pipeline or damage the sensor, further affecting the normal operation of the equipment. Therefore, target flow switches have high requirements for medium cleanliness especially in high-precision measurement and long-term stable operation scenarios.

II. Medium cleanliness requirements for target flow switches

1. Solid particle size limit
   Target flow switches usually require that the size of solid particles in the medium does not exceed a certain range. Generally speaking, the particle diameter should be less than 1/10 of the pipe diameter. For example, in a DN50 pipe, the particle diameter should be less than 5mm. Particles that are too large will not only damage the target plate but may also block the pipe, affecting the accuracy of flow measurement.

2. Impurity concentration requirements
   The concentration of impurities in the medium is also an important indicator. High concentrations of impurities will increase the wear and tear of the target plate and shorten the service life of the equipment. Therefore, target flow switches usually require that the concentration of impurities in the medium be below a certain value, and the specific value needs to be determined according to the equipment model and application scenario.

3. Relationship between medium viscosity and cleanliness
   High-viscosity media are more likely to carry impurities, so when choosing a target flow switch, the viscosity characteristics of the medium need to be paid special attention to. For high-viscosity media, it is recommended to add a filter device to the system to ensure that the medium cleanliness meets the requirements.

4. Chemical compatibility
   Chemical substances in the medium may also affect the performance of the target flow switch. For example, corrosive media may damage the target plate or sensor, leading to measurement errors. Therefore, when choosing a target flow switch, it is necessary to ensure the chemical compatibility of the equipment material and the medium.

III. How to ensure medium cleanliness

1. Install a pre-filter
   Install upstream of the target flow switch pre-filter is one of the most effective ways to ensure medium cleanliness. The filter can intercept solid particles and impurities in the medium, preventing them from entering the flow switch. According to the characteristics of the medium, filters of different precisions can be selected, such as mesh filters, bag filters, or magnetic filters.

2. Regular cleaning and maintenance
   Even if a filter is installed, a small amount of impurities may still remain in the medium. Therefore, Regular cleaning and maintenance is the key to ensuring medium cleanliness. It is recommended to formulate a reasonable cleaning plan based on the equipment usage frequency and medium characteristics to ensure the cleanliness of the target plate and the inner wall of the pipe.

3. Choose the right installation location
   The installation location of the target flow switch will also affect the cleanliness of the medium. For example, installing the flow switch at the lowest point of the pipe may cause impurities to accumulate around the target plate. Therefore, it is recommended to install the flow switch in the horizontal or vertical section of the pipe to reduce the risk of impurity accumulation.

4. Use high-quality media
   Whenever possible, use high-quality media. For example, in hydraulic systems, using high-purity hydraulic oil can reduce the impact of impurities on the flow switch. In addition, regularly replacing the medium is also an effective method to ensure cleanliness.

5. Monitor medium cleanliness
   In some high-requirement application scenarios, you can install online cleanliness monitoring equipment to monitor the cleanliness of the medium in real time. When the cleanliness does not meet the standard, the system can automatically alarm or start the cleaning program to avoid the impact of impurities on the target flow switch.

IV. Case study: Application of target flow switch in industrial water treatment

In industrial water treatment systems, target flow switches are often used to monitor water flow. However, industrial water often contains impurities such as mud and rust, which can seriously affect the performance of the flow switch. To solve this problem, a water treatment plant installed an upstream target flow switch two-stage filter . The first-stage filter intercepts large-particle impurities, and the second-stage filter intercepts small-particle impurities. In addition, the plant also formulated a monthly cleaning maintenance plan to ensure that the medium cleanliness is always in an ideal state. Through the above measures, the measurement accuracy and service life of the target flow switch have been significantly improved.

V. Common problems and solutions

1. What if impurities adhere to the surface of the target plate?
   If impurities adhere to the target surface, the flow switch can be disassembled and the target plate cleaned with a soft cloth or a special cleaning agent. Note: Do not use hard objects to scrape, to avoid damaging the target surface.

2. What to do if the medium cleanliness does not meet the standard, resulting in measurement errors?
   If the medium cleanliness does not meet the standard, first check if the filter is working properly. If the filter is working properly, consider increasing the filter accuracy or replacing it with a higher quality medium.

3. How to determine if the medium cleanliness meets the standard?
   The cleanliness of the medium can be determined through visual inspection, laboratory analysis, or online monitoring equipment. If obvious impurities or sediments appear in the medium, it indicates that the cleanliness does not meet the standard.

From the above analysis, it can be seen that, medium cleanliness is one of the key factors affecting the performance of the target flow switch. Only by fully understanding the requirements of the medium cleanliness and taking effective measures to ensure cleanliness can the long-term stable operation of the target flow switch be ensured. It is hoped that the content of this article will provide valuable reference for a wide range of users.