What is the relationship between the outer diameter of seamless steel pipes and their nominal diameter?
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How is the outer diameter of seamless steel pipes according to GB/T 17395 standard correlated with the nominal diameter? For example, what is the nominal diameter of a steel pipe with an outer diameter of 180?
How does this correspond? This standard should apply to all seamless steel pipes, regardless of whether they are used for fluids or not. For steel pipes used in fluids, ASME B36.10M can be referred to; the national standard is unknown.
Indeed, this is the outer diameter of all seamless steel pipes; for many series, it’s not possible to determine their nominal diameter, as the term \"nominal diameter\" refers to a concept in pipeline design rather than a parameter specific to steel pipes. Therefore, I can only preliminarily conclude that if no corresponding nominal diameter can be found, it is likely that these pipes are used as structural seamless pipes
However, in API standards, there are also steel pipes for fluids that are not classified based on nominal diameter. In fact, once the nominal diameter is known, there are standard products available for the corresponding fittings, so no customization is needed.
Do you use pipes with a diameter of DN175 frequently? Is it difficult to find valves suitable for them? There are very few pipe design standards and valves available for DN175
This post was last edited by Thank goodness you're here on 2015-12-18 11:23. I’ve never heard of that size. It is usually DN150 or DN200. Additionally, for sizes below 14", the actual outer diameter is not a multiple of 25.4, which is the nominal diameter.
I usually refer to SH3405 when checking the nominal diameter and outer diameter. . .
As a personal suggestion, you could reverse the correspondence – that is, use the nominal outer diameter to determine the diameter, because for some pipes, unfortunately, there is no nominal diameter available for reference :)
That’s right; the production of steel pipes is defined by their dimensional specifications. The nominal diameter is a parameter used in pipe design, but there isn’t always a one-to-one correspondence between the two, as steel pipes are not only used for piping purposes but also for structural applications. Only pipes used in piping applications have the concept of nominal diameter