Differences among pipeline series
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Pipes are divided into two series: large outer diameter and small outer diameter! But apart from the difference in outer diameter, what are the differences in inner diameter and wall thickness? After checking SH3405, no information was found regarding pipes with a smaller outer diameter. I hope everyone can explain it! ! :)
Nominal diameter Outer diameter mm HG20553 ISO4200 GB/T17395 Series I SH3405 JIS ASME B36.10 Series A Series B 3/8 10 17.1 14 17.2 17.2 17 17.3 17.1 1/2 15 21.3 18 21.3 21.3 22 21.7 21.3 3/4 20 26.7 25 26.9 26.9 27 27.2 26.7 1 25 33.4 32 33.7 33.7 34 34 33.4 1 1/4 32 42.2 38 42.4 42.4 42 42.7 42.2 1 1/2 40 48.3 45 48.3 48.3 48 48.6 48.3 2 50 60.3 57 60.3 60.3 60 60.5 60.3 2 1/2 65 73 76 76.1 76.1 76 76.3 73 3 80 88.9 89 88.9 88.9 89 89.1 88.9 4 100 114.3 108 114.3 114.3 114 114.3 114.3 5 125 141.3 133 139.7 139.7 140 139.8 141.3 6 150 168.3 159 168.3 168.3 168 165.2 168.3 8 200 219.1 219 219.1 219.1 219 216.3 219.1 10 250 273 273 273 273 273 267.4 273 12 300 323.8 325 323.9 323.9 325 318.5 323.8 Hope this is helpful to you
ASME standards are all based on the outer diameter for piping systems; petroleum standards follow ASME, while smaller pipes are not covered by these standards
The terms \"large outer diameter\" and \"small outer diameter\" are conventional expressions. For steel pipes, there are two different outer diameters for the same nominal diameter, and these correspond to different manufacturing standards. Seamless steel pipes have various standards related to their small outer diameter, such as GB8163; welded steel pipes, on the other hand, have standards related to their large outer diameter, such as GB3091. To make a precise distinction, it is necessary to compare these standards.
When China’s petrochemical industry was established, it imported equipment from the former Soviet Union, all of which belonged to the small outer diameter series (i.e., Series B in the current European system). Since the 1990s, when China began to introduce large-scale ethylene plants, the ASMI standards from the United States were adopted. It was found that these standards differed from those in use domestically at that time; pipes with the same nominal diameter had different outer diameters, which led to the classification of them into large outer diameter and small outer diameter series. At that time, the only standard available in China was one with a small outer diameter, namely the standard set by the Ministry of Machinery. Since Sinopec introduced a large number of ethylene production facilities, in order to localize the production of pipes and fittings as soon as possible, Sinopec adopted the ASMI standard as a basis, using it largely in the development of its own standards. Therefore, this standard only includes a large outer diameter series, with no small outer diameter series.