Pressure issues of vertically mounted lids with necked butt-welded manholes
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The last edit to this post was made by carson821021 on 2010-7-27 at 09:03. HG/T 21521-2005 states that this standard is applicable to pressures ranging from PN2.5 to 6.3 Mpa; however, the highest pressure listed in the table provided later is only 4.0 Mpa. Could someone please explain this?
Is the poster sure it’s the HG/T 21512-2005 standard?
I really haven’t taken a close look at the HG/T 21512-2005 standard
Reply to 2# 690840741: Haha, sorry, I mistyped it as HG/T 21521-2005
Indeed, there is no specification size of 6.3 Mpa in HG/T 21521-2005. I think it might be due to high stress; considering hole reinforcement, it is likely to be a forged reinforcement pipe (reinforcement rings are not suitable). In this case, the size of the fitting is not fixed and cannot be determined.