Lathe bevel pipe stub for weld practice

Hi everyone
To use lathe to machine a prep, the bevel, on the end of a short piece
of pipe for practicing pipe-welding - what is a secure way to grip it
in lathe?
Would hope to take the same pieces back to the lathe repeatedly - can
plasma-cut apart completed welds.
Took pieces of my 140mm dia by 10mm wall-thickness pipe (about 5~1/2"
dia by 3/8" wall-thk) to a lathe. But guy rightly nervous - smallish
3-jaw chuck wound outwards to grip pipe internally on outer steps on
chuck-jaws - but like "hanging on by fingernail ends" and pipe pieces
about 200mm (8") long.
Obviously, my mind can throw up ideas like - weld three small blocks
to the bore of the tube at the chuck end so that you can slide in a
near-internal-dia disk with a drawbar which goes right through the
headstock and pulls on the back of the spindle. Etc
What does anyone really do?
Rich Smith