flow and return going into one valve?

[CXR100]

my old collage tutor told me that you can cut a piece of 8mm and it will thread in itself because it is soft enough, true???????

 

[Unregistered]

Hi,

trying to to remove a radiator with combined flow and return valve. Have managed to bleed the radiator but having trouble removing it due to the pipe that runs the length of the radiator? Do I simply cut the tube to remove the rad? Don't want to cut it and then have a huge leak!!

Thanks