How to reduce the wear of acid and alkali resistant chemical pipes

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How to reduce the wear of acid-alkali resistant chemical pipes
In the chemical industry, acid-alkali resistant chemical pipes are the link between various production links, and the stability and durability of their performance are directly related to production efficiency and safety. However, due to the complexity of chemical media and the harshness of operating conditions, acid-alkali resistant chemical pipes often face serious wear problems, which not only shortens the service life of the pipes, but also may cause production accidents. Therefore, how to effectively reduce the wear of acid-alkali resistant chemical pipes has become an urgent problem for chemical companies. This article will discuss in depth how to reduce the wear of acid-alkali resistant chemical pipes from the aspects of corrosion classification, wear causes, preventive measures and innovative repair methods.

1. Classification and wear causes of chemical pipeline corrosion
The corrosion phenomenon in the chemical industry is complex and diverse. It can be divided into metal corrosion and non-metal corrosion according to the type of material; it can be divided into comprehensive corrosion and local corrosion according to the surface morphology. Local corrosion includes pinhole corrosion, stress corrosion cracking, crevice corrosion, galvanic corrosion, wear corrosion, etc.; metal corrosion can be divided into physical corrosion, chemical corrosion and electrochemical corrosion according to the mechanism. Acid-alkali resistant chemical pipelines are mainly faced with chemical corrosion and electrochemical corrosion, and these two corrosion modes are particularly prominent in acid-base environments.

The wear of acid- and alkali-resistant chemical pipelines is mainly caused by the following factors:

Medium characteristics: Chemical media often contain corrosive components, such as acid, alkali, salt, etc. These components will react chemically with the pipeline material, causing corrosion on the pipeline surface. At the same time, the faster the flow rate of the medium, the stronger the scouring effect, and the more serious the wear on the pipeline surface.
Material selection: If the pipeline material is not resistant to acid and alkali corrosion, or the corrosion resistance of the material does not match the medium, the corrosion and wear of the pipeline will be accelerated. In addition, the roughness of the pipeline surface will also affect its corrosion resistance. The rougher the surface, the more susceptible it is to attack by corrosive media.
Operating conditions: High temperature and high pressure operating conditions will aggravate the corrosion and wear of the pipeline. For every 10°C increase in temperature, the corrosion rate may increase by 1 to 3 times. At the same time, pressure fluctuations in the pipeline may also cause fatigue damage to the pipeline material.
Construction quality: The welding quality and coating quality during the pipeline construction process will also affect its corrosion resistance. Welding defects may cause stress concentration, accelerate the corrosion and rupture of the pipeline; poor coating quality cannot effectively isolate the corrosive medium and reduce the corrosion resistance of the pipeline.
2. Measures to reduce the wear of acid-alkali resistant chemical pipes
For the wear problem of acid-alkali resistant chemical pipes, measures can be taken from the following aspects:

Reasonable material selection: Select appropriate pipe materials according to the characteristics of the medium and operating conditions. For highly corrosive media, alloy steel, stainless steel or plastic pipes with excellent corrosion resistance should be selected. At the same time, the temperature and pressure resistance of the material should be considered to ensure that the pipe does not deform or rupture during long-term use.
Optimize structural design: Rationally design the structure of the pipe to reduce the scouring effect of the fluid on the pipe. For example, in places where the direction of the fluid suddenly changes, such as elbows and tees, set guide plates or change the direction of the pipe to reduce the flow rate and scouring force. In addition, the wear resistance of the pipe can be improved by increasing the wall thickness of the pipe and using double-layer pipes.
Strengthen the protection of anti-corrosion coating: Applying anti-corrosion coating on the surface of the pipe can effectively isolate the contact between the corrosive medium and the pipe material and extend the service life of the pipe. When selecting anti-corrosion coating, its corrosion resistance, adhesion and wear resistance should be considered. Commonly used anti-corrosion coatings include epoxy resin, polyurethane, glass flakes, etc. During the construction process, the coating should be ensured to be uniform and free of defects to improve its anti-corrosion effect.
Strictly control the operating conditions: During the operation, the temperature, pressure and flow rate of the medium should be strictly controlled to avoid exceeding the bearing range of the pipeline material. At the same time, the pipeline should be inspected and maintained regularly to promptly detect and deal with potential corrosion and wear problems.
Adopt innovative repair methods: For pipelines that have been worn, innovative repair methods can be used for repair. For example, using high-performance materials such as KNM22 chemical acid-resistant glue to coat and repair the worn parts can effectively restore the corrosion resistance and wear resistance of the pipeline. In addition, surface engineering technologies such as thermal spraying and surfacing can be used to strengthen the pipeline to improve its wear resistance and corrosion resistance.
3. Practical application of innovative repair methods
Taking KNM22 chemical acid-resistant glue to repair acid-resistant and alkali-resistant chemical pipelines as an example, the specific steps are as follows:

Inspection and preparation: First, inspect the pipeline to determine the wear location and degree. Then, perform surface treatment on the worn parts to remove impurities such as rust and oil stains to ensure that the coating is well bonded to the substrate.
Configuration and coating: KNM22 chemical acid-resistant glue is configured in a certain proportion, stirred evenly and applied to the worn parts of the pipeline. During the coating process, attention should be paid to scraping and pressing to ensure uniform coating thickness and no bubbles.
Curing and inspection: After the coating is applied, it is cured. The curing time depends on the ambient temperature and humidity. After the curing is completed, the coating is inspected to ensure that it is of qualified quality and has no defects. If necessary, a second coating can be performed to achieve the required thickness.
In addition to KNM22 chemical acid-resistant glue, other innovative repair methods can also be used, such as polypropylene spiral protective sleeves. This protective sleeve has the characteristics of high wear resistance, oil resistance, corrosion resistance, arbitrary bending and free cutting, and is suitable for the protection of easily worn parts such as hydraulic oil pipes in pickling lines.

IV. Conclusion
Reducing the wear of acid and alkali resistant chemical pipelines is a systematic project that requires multiple aspects such as material selection, design, construction, operation and maintenance. By rationally selecting materials, optimizing structural design, strengthening anti-corrosion coating protection, strictly controlling operating conditions, and adopting innovative repair methods, the service life of acid- and alkali-resistant chemical pipelines can be effectively extended, and production efficiency and safety can be improved. In the future, with the continuous emergence of new materials and new technologies, the wear resistance and corrosion resistance of acid- and alkali-resistant chemical pipelines will be further improved, providing a strong guarantee for the sustainable development of the chemical industry.