Determination of the minimum attenuation coefficient
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I would like to ask: According to GB/T16508.3, if the pitch between two adjacent holes in a hole row is not equal to the value calculated using Equation 23, it is not necessary to calculate the hole bridge reduction factor. How is the hole bridge reduction coefficient determined? In this case, if the calculated longitudinal reduction factor is 0.87, the welding joint factor is 1, and there are no values for transverse or diagonal reductions, what should be the minimum reduction factor? Should it be 1 or 0.87? Why calculate the actual attenuation coefficient even after the thickness of the pot shell is determined? What’s the use of it?
There’s no need to answer the question about the actual reduction factor; I’ve found the answer myself. I’m sorry – it’s my first time dealing with calculations related to the strength of boilers, so I asked many silly questions. Please forgive me.
If the pitch between adjacent holes in a hole row is not equal to the value calculated using Equation 23, it is not necessary to calculate the hole bridge reduction factor. In this case, there is no need to calculate the perforated bridge; in other words, it should be treated as having no pores. This point is particularly important for large pipes such as centralized downcomers, as such pipes usually require reinforced structures. However, according to this standard, two adjacent holes cannot be reinforced simultaneously, and the provisions of this standard do not apply in such cases; therefore, it is common to increase the hole spacing beyond the value calculated using Equation 23.