Calculation method for openings on the head
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How to calculate the opening on the head of this structure? The height of the necked butt welding flange is 75mm. Open N3 port, butterfly head THA2200x10 Q345R, design pressure 0.6MPa, temperature 350 degrees.
The stress on the transition section of the head is relatively complex, so it is not good to open it at this position. If the length of the cylinder can be increased, it is better to place it on the cylinder. Sometimes smaller nozzles are opened in this way. I personally think that the longest opening slope is used as the outer diameter of the pipe, and the opening is perpendicular to the curved surface for reinforcement.
It is best to use stress analysis method for calculation.
This opening calculation converts the N3 opening into a large diameter opening. Others are fine, but N3 openings may not be counted.
This opening bending moment will play a large role and only stress analysis can be used.
This is the first time I have seen such a perverted takeover.
After thinking about it, I guess there is only stress analysis. If I haven't calculated it carefully, I can try using the long axis of the hole as the diameter of the hole. However, from the picture, the hole will be very large and may exceed the calculation range.
The ratio of the long and short axes of the opening should be greater than 2, and the equal area method is not applicable. The large opening analysis method in 150 is not applicable to the head. SW head openings are only normal and parallel to the axis. You can only use finite element Ansys and then perform stress assessment.
There is no place for inappropriate reinforcements.
This calculation method does exist, but it is not a domestic standard. In ASME Volume VIII, Div 2, Section 4.5, there is a calculation method as shown in the figure, but there are also some size restrictions. The specific poster can refer to it. If you really meet the prerequisites and plan to adopt it, you must also apply to * * The State Administration for Market Regulation provides a compliance statement that this method meets my country's basic safety requirements. In addition, why not make a longitudinal pipe parallel to the axis and lead it up first, and then bend it at 90 degrees to the transverse direction?