150 for the 24th, required root and cover weld heights.
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For version 24, the required allowance for welds A and B is as specified in Table 3 (Note: if the calculated value obtained by multiplying the percentage by the thickness is less than 1.5 mm, 1.5 mm shall be used). This requirement was not present in the older versions; it seems that the requirements have been relaxed. Calculatively, the allowance height for thicknesses up to 10 mm is 0–1.5 mm. For welds produced by type I submerged arc automatic welding, where there is no artificial notch, should they still be considered as type I notches? If they are to be regarded as such, then how should the weld’s remaining height be calculated – based on a single-sided notch or a double-sided notch?
According to the new standard (version 24), when the calculated weld bead height is less than 1.5 mm, it should be taken as 1.5 mm. For material thicknesses of 10 mm or less, the weld bead height should be between 0 and 1.5 mm. For welds produced by Type I submerged arc automatic welding, if no artificial notch is created, they are generally not considered to be of Type I notch type. The calculation of the weld excess height should be based on a crack-free Type I weld, and it is usually calculated as for a single-sided weld. .
I also have doubts about calculating the remaining height for this Type I groove, but there is no authoritative explanation; I simply specify 0–1.5 in the process specifications