Abstract: A radially compressible heating element is located about concentric overlapped heat fusible elements temporarily mounted upon a mandrel to form an annular seal between the heat fusible elements upon energization of the heating element.

Abstract: A weight monitor includes a first part for attachment to a pedestal or other support member and a second part for suspending a blood collection bag to be filled by a flow of blood from a donor. A trough shaped spring interconnects the first and second parts and retains the second part in fixed positional relationship to the first part until the bending force imposed upon the spring by the filling blood collection bag exceeds a predetermined value at which point the spring flexes abruptly and the second part becomes positionally reoriented with respect to the first part. A clamp, associated with the fill tube of the blood collection bag, is actuated by the reorientation of the second part to terminate further flow of blood through the fill tube into the blood collection bag.