Certainly is. You could even put a threaded coupler on the end of the pipe then a threaded cap so you could screw/unscrew the main cap. Plain end caps will fit plenty snug simply pressed into place but can be tough to remove if you accidentally bump the end or drop it, forcing it even tighter onto the tube.
I do know I'd go the PVC route if I needed what you want.
home depot sells pre-cut 2 ft sections of pvc pipe here - they cost about the same as a 10 ft - like $3 for 1 1/4" if I remember correctly. unthreaded caps are like $.50 or $1