For long-distance pipelines transporting brine at a pressure of 6 MPa, what type of pipeline material is suitable?
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It was also considered to use carbon steel with anti-corrosion measures; for long distances, the pressure can be managed adequately with carbon steel that has been treated for corrosion resistance, but dealing with welds and valves poses significant problems, as corrosion at those areas is quite severe. After further investigation, and taking into account experience from other projects, for media in the plant area that are subject to acid and alkali corrosion, fiberglass-reinforced plastic pipes and steel-reinforced PE pipes are generally used; these two types of pipes are also commonly employed in long-distance, low-pressure areas in flat regions. For this project, long-distance brine transport pipelines with a length of 60–70 km are being used; the design pressure for these pipelines is 6 MPa. The terrain is complex and uneven, and in some areas the soil contains high levels of moisture, while in other areas rock drilling is required. At present, non-metallic materials such as fiberglass pipes and steel-reinforced PE pipes are being considered, and according to the manufacturers, these materials can withstand pressures of 7–8 MPa. Regarding fiberglass-reinforced plastic pipes, I think that although they can meet the pressure requirements, their toughness is not very good; steel-reinforced PE pipes also have similar issues. I don’t have much experience in materials, and I’ve only recently started working with long-distance pipelines. I would appreciate it if everyone could provide some analysis; thank you~
By the way, the diameter design is DN200~250
10CrMoAl should be a suitable choice; aluminum oxide forms a passivation film that provides corrosion resistance, while the combination of Cr, Mo, and Al effectively prevents pitting corrosion caused by chloride ions.
First of all, thank you for your reply. 10CrMoAl is a steel alloy that offers good resistance to seawater corrosion. I checked some relevant information; this type of steel is suitable for use in seawater. Long-distance pipelines are generally buried underground, where the oxygen content in the soil is very low, making it impossible to form an effective oxide film (Al2O3). Moreover, the soil contains almost no chromium (Cr) or molybdenum (Mo) ions, which are needed to replenish the areas of the steel that have been corroded. Perhaps this type of steel is not very suitable for this project. Thank you!
My suggestion is to use nylon pipes; steel-reinforced nylon pipes or pure nylon pipes will all meet the required pressure standards, as well as withstanding lateral and longitudinal tensile forces. They also offer excellent corrosion resistance and acid-alkali resistance
Can PPH pipes be used? Is there any?
I think when using non-metallic pipes, it’s necessary to line the surrounding area with sand. I’m not sure whether your long-distance pipeline passes through any fault planes
If you are considering alloy materials, feel free to consult me!