A device for welding plastic tubes includes a pair of tube holders each of which has a tube clamp which includes an upper jaw and a lower jaw. The jaws in both of the tube clamps of both tube holders have smooth tube contacting walls to permit the tubing to slip through either side when the tube holders and tubes are being moved from a loading station to a stripping station to increase the length of fluid free area in the clamped tubes. A cutting/welding station provides for cutting the tubes and welding them together.