Allowable stress issue for saddle Q345R
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According to Table 1 of NB/T47042-2014, the allowable stress for the saddle material Q345R is either 200 or 170. In Table 15 of NB/T47065.1-2018, however, the allowable stress for Q345R is only 170. For the calculation of saddles with a design temperature of ≥-40～100°C, should the allowable stress be taken as 200 or 170?
When selecting the allowable stress, values from the latest standards or codes should generally be used. Therefore, you should refer to the more up-to-date NB/T 47065.1-2018 standard; for the calculation of saddles with a design temperature of ≥-40～100℃, the allowable stress should be set at 170. However, specific applications may require consideration of other factors such as actual operating conditions and safety factors; it is best to make a decision after discussing it with relevant engineers or project managers. .
If you look at the SW6 calculation sheet, you will find that it is based on 47042 for the calculations
When using SW6, the allowable stress specified by SW6 itself should be applied; when using 47065, 170 should be used