The issue of using a fixed tube sheet as a flange
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I would like to ask: when the fixed tube sheet also serves as a flange, is it acceptable to use carbon steel with a lining ring for the equipment flange, while using stainless steel for the tube sheet? Are the materials at both ends of the device’s studs different?
This post was last edited by SDHZZXM on 2016-12-30 at 15:54. It’s okay. The material at both ends of the device’s studs should be the same...
The materials at both ends of the device’s studs should not be the same… Does that mean it’s okay for them to be different?
The materials at both ends of the device’s studs should not be the same… Does that mean it’s okay for them to be different?
Sorry, it should be “should be consistent”; it has been edited accordingly.
It’s way too permissive. The studs do not come into contact with the medium, so carbon steel is sufficient
This design approach is very common in fixed-tube-sheet heat exchangers. Fasteners are generally not made of stainless steel, as using such material can lead to seizure. When the thickness of the tube sheet is considerable, and the material flowing in the shell side is not corrosive, the tube sheet is usually constructed from composite materials.
Did I not express myself clearly? The fasteners are made of carbon steel, the flanges used to secure the tube sheet are made of carbon steel with lining rings, while the tube sheet itself is made of stainless steel. What I mean is that instead of using stainless steel for the tube sheet, it would be better to use carbon steel to which stainless steel is welded on, right?