Methods of using compression collars for coupling a tube to a tube fitting

A method for sealing a tube to a tube fitting, the method comprising:

• radially expanding a compression collar from a constricted state to an expanded state, wherein the compression collar is resiliently flexible, tubular and comprises a throughway extending through the compression collar;
• positioning the throughway of the compression collar over at least a portion of the tube and the tube fitting;
• allowing the compression collar to resiliently rebound to compress the tube against the tube fitting;
• and
• applying a first type of radiation to the compression collar while or after the compression collar resiliently rebounds to the constricted state to further seal the tube to the tube fitting and sterilize the compression collar and seal.