How long should wait after the ball tank is welded before heat treatment is carried out? ? ?

There’s no rule specifying this, but after welding, non-destructive testing must definitely be carried out first; heat treatment can only proceed once the non-destructive testing results are satisfactory.

Speaking of heat treatment after welding, it should be a full-scale heat treatment. GB150 requires that such treatment be carried out after all welding work on the spherical tank has been completed and after non-destructive testing has given satisfactory results. Generally, for the welds formed by welding the upper and lower halves in our factory, the timing of non-destructive testing is determined based on the material of the spherical shell: for Q345R, testing is usually carried out 24 hours after welding; for Q370R, it is 36 hours later; for other chromium-molybdenum steels, it is 48 hours later. The specific timing for non-destructive testing is specified in the technical contract drawn up by the design institute. By the same logic, the timing for on-site non-destructive testing can also be determined using this as a guide. Once non-destructive testing shows satisfactory results, heat treatment can proceed