A method for calculating the range of crimping stamped-welded tees pressures is proposed. The application of this technique at the stage of welded pipes final inspection allows to completely removing residual welding stresses by metal plastic deformation in the maximum stress concentration zones near the welded joints. The result of this procedure is increasing the pipeline systems durability and working resource.

An energy efficient Т-joint unit manufacturing technology has been developed for vertical steel tanks. This technology is based on the T-joint welding using unequal weld seams.

A mathematical model for assessing the vertical steel tanks durability under lowcycle loading is presented. А pulsating cycle for loading objects according to the «pouring – filling» scheme is considered. This model is based on the use the stress concentration efficiency factor. It describes the material fatigue curve with a stress concentration effect.