A tube fitting for connection to a tube includes a main body structure and a tube liner. The main body structure is configured to receive an end of the tube and fluidly connect the tube to another component. The tube liner is positioned at least partially within the main body structure and is configured to extend into the tube. The main body structure and the tube liner are configured such that, when the tube is fully inserted into the tube fitting, the end of the tube is positioned at a predetermined depth within the tube fitting, and the main body structure and the tube liner cooperate together to provide an audible indication to indicate that the tube has been fully inserted into the tube fitting.