Oliynyk O. Increase of efficiency and safety of main gas pipelines repair by arc welding at exploitation conditions.

Dissertation is devoted to the questions of increase of efficiency of actions those provide safe performance of arc welding at in-service repair of main gas pipelines and repaired parts working capacity. The numerical technique of main gas pipelines defective parts failure risk estimation has been developed and principles of ranking of damages on degree of danger at in-service repair have been formulated. Influence of the factors those provide safety at welding repair of pipe wall thinning has been studied. Degree of influence of conditions of welding and main pipelines exploitation on risk of cold cracks formation in welded joints has been estimated. The conditions those provide the efficiency of the use of welded pressure-tight pipe sleeves of various designs at main gas pipelines in-service repair have been formulated. The system of the methodical actions that provides the efficiency and safety of welding repair at works on the main gas pipelines at exploitation conditions has been offered.