FIELD: transportation of gas. SUBSTANCE: process of quick change over of turbocompressor from parallel connection into off-line mode of operation at compressor station of gas main can be accompanied by rising mechanical action, especially, vibrations, on recirculation pipeline and additional risk of stalling-and-surging of compressor. Proposed invention relates to method and device aimed at decreasing vibration loads and increasing efficiency of prevention of stalling-and-surging of turbocompressor when the latter is changed over for off-line mode of operation by changing position of stalling-and-surging control line which is displaced at preset velocity from initial position into preset new position and decreasing braking velocity of turbocompressor at intersection by working point of stalling-and-surging control line before said line reaches its new position. At completion of change-over operation, control line is returned into initial position, and decrease of velocity of compressor stops when preset value of velocity is obtained. EFFECT: reduced vibration loads and stalling and surging of turbocompressor. 16 cl, 3 dwg
