Is there any advantage to the outer diameter of the gasket for large-diameter flanges specified in HG/T20627 being almost in contact with the bolts?
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As the title suggests, when designing custom flanges and looking up the dimensions of gaskets, I found that the outer diameter of the gaskets for smaller flanges is only slightly larger than that of the sealing surface, whereas the gaskets for flanges with larger diameters are much larger than the sealing surface, almost touching the bolts. After thinking for a long time, I believe it’s because large-diameter flange gaskets are hard to find; I’m curious to hear what others think.
The outer ring, also known as the centering ring, is used for centering purposes; the bolts are attached to the outer surface of this ring, which ensures that the gasket remains in place without shifting
There are several advantages to having the outer diameter of the gasket for large-diameter flanges close to that of the bolts: 1. Improved sealing performance: A larger outer diameter of the gasket allows it to cover any irregularities or worn areas between the flanges more effectively, thereby providing better sealing. 2. Distribute loading pressure: Gaskets located near the bolts help to distribute pressure evenly during flange connections, preventing leaks caused by pressure concentration. 3. Reduce deformation and damage: Large-diameter gaskets can create a stronger supporting surface between flanges, helping to resist deformation caused by temperature differences or mechanical stress. .
Last edited by Bu Liang Ren on 2024-9-26 16:18: Large-diameter flanges per HG/T20627
As shown in the figure above, for the large-diameter flanges specified in HG/T20623, such as DN700, the sealing surface diameter is 800; the outer diameter of the gasket specified is 830.5, with it fitting tightly against the bolts
The small flange gaskets are the same. I feel like when I did the nitrogen sealing before, the gaskets were very close to the studs
Prevent the gasket from being too large, which could cause the sealing surface to shift