Column design transition section
Thread Content
I am a college graduate who has been working in the design and manufacturing of pressure vessels for two years. In my work, I have seen that on the drawings of towers designed by our company’s seniors, some have a transitional section at the junction between the skirt base and the tower body, while others do not； Moreover, for two different towers with the same diameter, the length of the transition section is also different – why is that? Please ask for guidance!
Generally, it is the case where the main body of the tower and the skirt are made of different types of steel, or when the temperature gradient is too large
It must be that the material of the skirt of this tower is different from that of the tower’s head; since the materials are different, welding can affect the properties of the material in the tower head. Therefore, a transition section made of the same material as that of the head is necessary to ensure that the properties of the head material remain unchanged after welding. If the head is made of 0Cr18Ni9 and the skirt is made of Q235-B, and there is no transition zone, the corrosion-resistant alloying elements at the weld site of the head will be diluted after welding, which can lead to localized corrosion of the head during use. At the same time, tower standards specify requirements for the length of the transition section: for towers with a design temperature of t > 250°C or -20°C to 250°C, the transition section must be at least 300 mm long. Dear colleague, I wonder if you’re satisfied with my answer?
What was said on the third floor makes a lot of sense; I’ve also learned that as well, thank you. But you mentioned that there are requirements in the standards for towers – could you tell me which standards those are? This post was last edited by llx123 on 2009-2-10 17:17]
SH3098-2000 or HG20652-1998
Can the head be made of Q345R and the tower body of Q35B without a transition section?