A brief discussion on the corrosion and protection of underground pipelines
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Most underground pipelines are made of steel pipes, and their uses are diverse and varied. To ensure the safety and long-term durability of pipeline systems, effective corrosion prevention holds particular importance. There are various methods for protecting steel pipes: the choice depends on factors such as the pipe’s intended use, the level of environmental corrosion, and the required service life. Pipeline protection (including construction and installation) has become a specialized industry with a complete set of procedures, standards, and specific implementation methods. Here, only the basic ideas behind protection methods can be briefly introduced. 1. Selection of steel pipe types: Steel pipes vary in terms of material and manufacturing processes; for example, those made from corrosion-resistant steel exhibit significantly better corrosion resistance compared to ordinary steel pipes. Seamless steel pipes made of the same material exhibit significantly better corrosion resistance than welded steel pipes (whose welds are prone to corrosion). Depending on the environmental corrosion conditions, there is a choice of steel pipe types, while taking its cost-effectiveness into account as well. 2. Selection of wall thickness: The “thickness margin method” was commonly used in the past, which involved choosing pipes with thicker walls to provide a \"margin,\" thereby extending their service life. This method may be effective under conditions of uniform corrosion, but in reality, uniform corrosion does not occur in most cases. One cannot rely solely on the \"thickness margin method\"; it must be used in combination with other protective measures (such as coatings, etc.). 3. Coating protection: This is the most common method of protection for underground (underwater) metal pipelines. Organic coatings, inorganic coatings, metal coatings, cement-based coatings, etc., can be selected based on the corrosive environment. 4. Isolation, lining, and construction layer: various types of fiberglass, tape wrapping, plastic pipe sleeves, or construction using brick tiles, etc. 5. Cathodic protection: For metal (steel) pipes used in highly corrosive underground (underwater) environments, where high safety standards and a long service life are required, it is necessary to consider applying cathodic protection measures. 6. Other methods for protecting pipes from the inside and outside.
I think using an inorganic coating in combination with cathodic protection is a relatively reliable approach
Corrosion of buried pipes Underground pipe corrosion prevention requires a solid foundation in materials science, physics, chemistry, as well as various engineering applications. Firstly, based on the material of the buried pipes, they can be divided into metallic and non-metallic. Different material properties result in varying corrosion prevention methods for buried pipes. At the outset of this discussion post, it is clearly stated that in considering materials for buried pipes, we limit our options to metal materials first. Thus, the corrosion prevention of buried pipes is discussed step by step. It is followed by a long list of theoretical and practical specialties that need to be explored step by step. This topic is great; please give the moderator who posted it some encouragement.