About the corrosion allowance of equipment
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May I ask what regulations or manuals describe the corrosion margin of the equipment? What conditions does the process major provide to the equipment major to determine the corrosion margin of the equipment?
This post was last posted by Bubble_ZPTK edited on 2019-2-11 16:41 API610 requirements for pumps 6.3.7 The pressure casing shall be designed with a corrosion allowance to meet the requirements of 6.1.1. Unless otherwise specified, the minimum corrosion allowance shall be 3 mm (0,12 in).
Without understanding the dynamic equipment, the corrosion margin for static equipment is the corrosion rate × expected life. If there is no corrosion rate, it is generally based on practical experience, the use of similar devices and equipment, or consulting the user.
I participated in a project to submit an equipment data sheet to the equipment major. The unified regulations issued by the institute require the corrosion margin of storage tanks to be implemented in accordance with the provisions of GB50341. However, I have searched through the specification and did not find the requirements for corrosion margin. Please help to clarify my doubts.
The provisions for corrosion allowance in the standard. It is generally determined based on the service life of the equipment and the corrosion rate of the medium on the material.
As 5# said, because there are many factors that affect corrosion, general specifications only give factors related to corrosion rate. The specific corrosion rate needs to be consulted in professional book specifications based on specific process parameters, or even measured through experiments. When it comes to specific projects, the specific values should be listed in the process documents. If not, you can consult Party A or the owner. Unless it is a common medium such as water, the value can be given according to the specification and the service life can be dealt with as appropriate.
HG/T20580 has some explanations, and the "Corrosion Data and Material Selection Manual" also has explanations. However, it is difficult to accurately determine the corrosion rate, especially for new processes and new media. Coupon tests are generally required to determine the corrosion rate. The C2 mentioned in terms of craftsmanship conditions is generally determined based on head-scratching.
I don’t understand your professional division of labor. Special media can only improve the corrosion margin through process! General common media and equipment professionals should also have a certain understanding and can be negotiated. In 50341, there is no specific value, but the corrosion margin of large storage tanks should not be too large! Can you tell me about the medium? I'll see if anyone knows about it.
Dear experts, do you have any more detailed courseware?
What the designer needs to know about this corrosion margin is that it should be roughly estimated based on the corrosion rate of uniform corrosion. The same medium has different corrosion rates under different pressures and temperatures, not to mention other complicated influencing factors. My opinion is that you don’t need to worry too much about the exact value, because there is no such value that can accurately leave the container to corrode according to the corrosion rate.
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