a machine for automatically sealing the end of various sized lengths of plastic tubing and for filling same has a clamshell clamp for straightening and firmly positioning the tubing , a carriage with an alignment ring which is lowered over the end of the tubing , a heat probe with a separate drive for insertion into the tube end to heat it , and a plurality of plows having depending guide legs which are simultaneously advanced radially inward against the heated tube end to collapse it and hold it as it cools , thereby creating a weld seal . an abrading arm assembly is mounted to the carriage and has an abrading brush or roller which may be rotated upon insertion into the tube end to roughen the inner surface of the tube end to enhance the weld seal . the tube straightener and the alignment ring positively align the pipe and the heat probe . a filler arm assembly is mounted to the carriage and may be extended to align with the tubing . a valve and cylinder in the filler arm automatically control the flow of the desired filler material into the tubing . the heat probe is of a modular construction with a quick release to facilitate its rapid removal and replacement for maintenance , or to change the operating temperature of the apparatus to suit tubing manufactured from different types of plastics . controls are provided to time the various operations and are fully adjustable to adapt the apparatus for different applications .