Groove shape for openings in flange covers
Thread Content
For N1 25/50 flanges, holes usually need to be made in the DN50 flange cover; the thickness of such flange covers is around 20 mm. I think a full penetration welding method should be used, that is, with double U-grooves and a root gap of 2 mm. However, some colleagues believe that it is not necessary to achieve full penetration for containers of this type; considering that welding might deform the small tubes, a groove design with double-sided 4x45° bevels is used instead. Do any of you work in equipment factories or design institutes? What are your thoughts?
It depends on a comprehensive consideration of the operating parameters of the specific container as well as the medium used. In the poster’s description, none of factors such as pressure, temperature, medium, material, or container type are mentioned, so it’s impossible to make a judgment.
If the properties of the medium are not extremely or highly hazardous and the equipment is not classified accordingly, it is not necessary for the weld to penetrate the entire cross-section, but it must still meet the requirements of relevant design standards.
For those governed by the fixed-volume gauge, a fully welded-through structure is required; therefore, for flange covers with high pressures or large diameters that have openings, we usually use a built-in fully welded-through structure
A container that does not fall into a specific category is not necessarily not a pressure vessel; it is still necessary to determine whether full penetration welding is required based on the operating conditions of that container and the standards applied.
Not classified; GB150, design pressure 0.3. The medium inside the container is explosive and poses poisoning risks.
As a preliminary judgment, it’s fine to follow your colleague’s advice.
For explosive media, in accordance with the requirements of solid volume regulations, a fully penetrated structure should be used.
Use an LWN flange directly in place of the pipe fitting, with a fully penetrative weld structure for the flange cover. Pay attention to having a craftsman’s spirit and producing high-quality equipment.
It is not governed by tolerance specifications; there is no requirement to use weld joints with full penetration across the entire cross-section.