What are the differences between the flanges specified in the standards SHT 3406-2013 and HG/T 20615?
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May I ask: What are the differences between the flanges specified in the standards SHT 3406-2013 and HG/T 20615? For example, what is the difference between the necked butt-weld flange specified in SHT 3406-2013 and the necked butt-weld flange specified in HG/T 20615? Thank you! !
These two standards have compatible specifications; both are based on ASME B16.5 and SH/T3406, with diameters of DN600 or larger, while HG/T20615 allows for diameters up to DN600
The methods of indicating flange grades vary; in the SH standard it is denoted as PN 20, while in 615 it is referred to as class. However, these are mutually convertible, and the flange dimensions are generally the same, allowing for compatibility when necessary. However, it is still best to use flanges that meet uniform standards.
More or less; HGT20615 follows the American standards, while SHT3406 has more detailed grades, which however causes confusion in maintenance but saves material.
Thank you for your reply. Recently, I noticed that the flange bolt holes in standard SH/T3406 are shown in the drawings as counterbored holes. Could you please explain this?
Thank you for your reply. Recently, I noticed that the flange bolt holes in standard SH/T3406 are shown in the drawings as counterbored holes. Could you please explain this?
I hadn’t noticed that; I can’t help you with it :)
I later checked the standards carefully to see whether it was a fisheye hole; thanks anyway~