A coupling device for connecting two ends of respective tubular members, allow the opening and the closing of a first tubular member and the simultaneous engagement of the two tubular members, as to prevent pollution, includes: a first case housing a first end of a respective first tubular member, comprising closing means of said first end; a second case, wherein a flexible terminal section of a respective second tubular member is received, comprising means for driving a second end of said second tubular member from a retracted position to a engagement position into said first end and vice versa; and means for reversibly connecting said first and second cases at a respective coupling port thereof, defining a single sealed environment; wherein the engagement and the disengagement of said second end and the automatic mechanical activation and deactivation of said closing means for opening and closing said first end.