Issues with the marking of HG/T20592 pipe flanges
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The last edit to this post was made by Panpan199081 on 2019-11-15 at 14:59. According to HG/T20592-1997, for the identification of flanges, the A series requires the letter (A) to be marked behind the flange; if no such mark is present, it is assumed to be the B series. In HG/T20592-2009, it’s the other way around: the B series requires the addition of (B), while the default for those without any marking is the A series. Original poster revised on 11/15/2019: After checking, the standard I downloaded was incorrect; the flange standards from version 97 and those from version 09 are identical in terms of their specifications. That is, A can be omitted, but B cannot. Such as WN100-4.0 and WN100 (B)-4.0. Reference link: http://www.docin.com/p-983565444.html (Docin.com – you can trust it)
2009 makes sense – the A series is used more often, so there’s no need to indicate it every time.
Just follow the new standards
This post was last edited by COLORZERO on 2019-11-11 at 16:24. Your version 97 is pirated; the original version is the same as the 2009 version. .
It was downloaded from the internet; sigh~ I’ve marked it all. Anyway, the standard only says that it’s optional, and it doesn’t say that marking it is wrong. Right? Considering the unit purchasing issue, and to prevent errors, I’ve marked them all. :lol