Increasing service life of chuck unit of tank during cyclic loading

Performance of the tanks depends on the tightness of all their components and joints, quality thereofis formed during the construction phase. Analysis of the results of the VST (vertical steel tank) examination shows that a greater number of defects are concentrated in the chuck unit of the tank - the place where wall and bottom meet. The main issue that arises in the installation of vertical steel tanks is technological lack of penetration of the chuck unit, as well as excess of the clearance in the joint of the welded joint directly prior to welding, due to high threshold deviations in the foundation base dimensions and imperfect assembly operations. Additional tensile stresses resulting from elastic deformation of the bottom to ensure the required clearance in the welding lead to premature failure of the tank. It has been experimentally shown that with increasing clearance in the joint (with subsequent reduction to the rated value), the fatigue life of the chuck unit decreases. Various types of additional treatment allowing one to prolongservice life of the chuck unit.