I have a question regarding the appearance of stainless steel pipes
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Our company is carrying out the construction of oxygen pipelines (the low-pressure pipelines prior to the compressors). The contractor supplies some of the materials, while our company purchases other materials. The material used is SUS304 stainless steel. The pipes supplied by the contractor have smooth inner and outer surfaces, whereas the stainless steel pipes purchased by our company have a matte finish on both the inside and outside; they look similar to carbon steel pipes that have just been descaled through shot blasting. I would like to ask everyone: why do stainless steel pipes made of the same SUS304 material have such different appearances?
Different manufacturers have varying element contents; some use 00Cr19Ni10 while others use 09Cr19Ni10； It is also possible that the steel is recycled, melted, and then molded.
The standards for pipes vary; the construction company may purchase sanitary pipes.
1. Check the material certificate of conformity； 2. Create a PMI to see the difference between the two. It’s estimated that what Party A bought is not authentic.
Sanitary-grade stainless steel pipes, commonly used in the food and pharmaceutical industries; both the inside and outside of the pipes are polished
Sanitary-grade stainless steel pipes, commonly used in the food and pharmaceutical industries; both the inside and outside of the pipes are polished
Use food-grade pipes, and pay attention to the wall thickness of the pipes
Just in terms of appearance, there can be different standards for surface treatment, meaning different levels of roughness. For the same pipe, its surface can be very rough or as smooth as a mirror.