FIELD: contact butt welding, namely methods and apparatuses for roller electric welding of shells of reservoirs, possibly at making tin shells, cans and other similar products. SUBSTANCE: method comprises steps of butt welding of lengthwise zones of shells by means of two electrodes having outer electrically conductive roller and inner electrically non-conductive roller; stationary mounting inner roller in such a way that it takes pressure effort at welding and forcing it to outer roller. EFFECT: improved design providing enhanced quality of welded joint. 14 cl, 16 dwg
