Materials on clinical application in cardiosurgery of Soviet-made apparatus for extracorporeal circulation, models (formula: see text) and (formula: see text) are presented. Modification of these apparatus aimed at securing separate sterilization of its pumping units and setting them in place as a complete aggregate is described. This is achieved by providing the pumping assembly with articulated lock bolts and locating grips diametrically on the faceplate of the pump over which, to temporarily fix the cover with distributing valves and the pump's diaphragms, a rubber plait is hooked on.