Effect of pipeline CO2 partial pressure on the selection of corrosion allowance
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At what CO2 partial pressure does it cause corrosion in carbon steel pipes? Generally, how should the corrosion allowance be selected within this range? It indicates that the pipe material is A106 Gr. B.
The partial pressure of CO2 should have no effect on the corrosion of carbon steel, and it can generally be ignored. The corrosion margin is generally taken as 1.5 mm or 1.6 mm.
Maybe I didn’t express myself clearly enough; I’m sorry. The medium in the pipeline is natural gas coming from the wellhead, which is wet gas.
Tell me the detailed parameters, and I can use InterCorr’s corrosion prediction software to help you analyze it.
Email contact: guochao.liu@honeywell.com
Natural gas generally contains a certain amount of carbon dioxide and water vapor; in some cases, it also contains hydrogen sulfide and sulfur dioxide. All of these substances have a corrosive effect on pipelines. To calculate the corrosion allowance for pipelines, it is necessary to know the composition of the natural gas, the design pressure and service life of the pipeline, as well as the gas temperature. If the gas contains no hydrogen sulfide or sulfur dioxide, or if their concentration is below 1 ppm, the corrosion allowance for the pipeline can be set at 1.5 to 2. Of course, the API standards require a more stringent approach when determining the corrosion allowance for pipelines!
First, it is necessary to determine the molar partial pressure to know whether corrosion will occur in the pipeline, and only then can the corrosion allowance be considered
At 15–20°C, with a CO2 concentration of 30 mol%, an operating pressure of 5.2 MPa, and wet natural gas (water dew point ≤ -10°C), what are the approximate corrosion rates for 16Mn, 20#, and 304? :lol