Questions regarding the interpretation of GB/T17395-2008
Thread Content
This post was last edited by Canghai Yishengxiao on 2011-2-1 09:29. Today I reviewed the GB/T17395-2008 standard. Are the dimensions of series 2 pipes specified in this standard those corresponding to metric pipes (the series with smaller outer diameters)? However, common outer diameter sizes such as DN65, DN80, DN100, etc., which are used in metric pipes in regular design work, can only be found in series 1 and 3. What is the reason for this? Could it be that my interpretation is incorrect? I hope those who are familiar with this issue can provide some help
The preface to this standard states that it corresponds to ISO4200:1991 and so on; therefore, I wonder whether it can be understood that GB17395-2008 belongs to the \"large outer diameter series\". Moreover, the main text does not mention metric or imperial pipes at all, but only states that \"Series 1 is a general series and is the recommended series\"； Series 2 is a non-standard series…” In the GB17395-98 version, it is stated here as “First series, standardized steel pipes” ； The second series consists of steel pipes that are primarily non-standardized... Therefore, it’s natural that the owner would encounter problems when trying to find sizes in the smaller outer-diameter series! It’s just my personal understanding; I’m not sure if it’s correct, so I hope experts can give their insights...
Standard outer diameter for steel pipes: There are welded and seamless types; the series 123 you mentioned refers to the outer diameter of welded steel pipes, and it is different from ISO standards.
GB/T17395-2008 \"Dimensions, Shape, Weight and Allowable Deviations of Seamless Steel Tubes\" is a standard related to the dimensional specifications of seamless steel tubes. Currently, **the newly published standard series are generally in line with international standards. The first series of seamless steel tubes specified in GB/T17395-2008 corresponds to the internationally standard series, that is, the imperial system. The second and third series consist of either the metric system still used in China or special series. Among the nominal diameters of DN65, DN80, and DN100, the outer diameters for DN65 and DN80 in the first series are of the imperial system; they also fall under the domestic metric system. The outer diameter for DN100 in the first series is 114.3 mm, which corresponds to the imperial system, while the value under the domestic metric system is 108 mm, belonging to the third series specified in this standard. In the future, the selection of seamless pipes, both in terms of design and manufacturing, will gradually move towards the first series of dimensions specified in GB/T17395-2008. The original poster should do the same when designing layouts.