OOO "Research Institute of Transneft" has improved the method of manufacturing the design of a vertical steel tank (RVS) through the use of new welding technology in the construction, reconstruction and repair of the tank. A patent of the Russian Federation has been obtained for the invention. This was announced by the company.
The development is designed to increase the operational reliability and durability of the RVS: it allows you to obtain high-quality, defect-free welded joints in the root layers of the seam during arc welding of the junctions of the tank wall with its bottom.
The technology proposed by the Transneft Research Institute involves welding butt joints by applying at least three welded rollers - root, filling and lining, while each subsequent welded roller overlaps the previous one by at least 70%.
Improving the quality of welded joints, among other things, is ensured by choosing the optimal welding arc pressure at various welding stages, ensuring the required temperature conditions: preheating the edge of the tank wall ends to a temperature of 150 to 160 ° C before applying the root roller and cooling the welded joint to a temperature of 50 ° C using thermal insulation belts after applying facing roller.
This welding technology of the coupling unit of the tank bottom with its wall is applicable in the construction, reconstruction and repair of low-carbon and low-alloy steels with a temporary tear resistance from 335 to 588 MPa and carbon equivalent (Seqv) from 0.28% to 0.46%.
According to the results of the conducted production tests, as well as ultrasonic inspection (ultrasonic inspection) of the welded joint, the proposed welding technology has confirmed its effectiveness. The non-destructive testing by the UZK method, which became possible after the application of the specified welding technology, showed the complete penetration of the technological gap between the welded elements of the tank structure, the absence of welding defects, as well as mechanical damage and cracks.
The application of the proposed method provides a high-quality welded joint. There are no welding defects such as "non-welding", "undercutting", "non-fusing edges". The resulting seam metal is characterized by high metallurgical quality and high mechanical (viscous and plastic) properties.
LLC "Scientific Research Institute of Pipeline Transport" It was established on September 3, 2009, and since November 12, 2014 it has been renamed OOO "Research Institute of Transneft". The Institute is entrusted with the function of the Registrar of the data bank on the protectable results of intellectual activity of the organizations of the Transneft system. Transneft Research Institute LLC is also entrusted with the functions of ensuring the conduct of energy surveys (energy audit) and the development of Energy saving and Energy Efficiency Improvement Programs for the facilities of the trunk pipelines of Transneft PJSC (until June 30, 2016 - Transneft Joint Stock Company for Oil Transportation).
