Apparatus and methods are described including a blood pump that includes a frame and an inner lining, which has a flexural modulus of between 0.1GPa and 2 GPa and lines at least part of the frame. An impeller, which is configured to pump blood of a subject, is disposed within the frame. A pump-outlet tube, which has a flexural modulus of between 0.1 GPa and 0.8 GPa, is fixed over at least part of the frame, and is heat welded to the inner lining. Respective melting temperatures of the inner lining and the pump-outlet tube are within 20 ˚C of one another. Other applications are also described.