What is a breather tube (Capillary Tube)?

A breather tube is a small hollow tube found in insulated glass units. The function of a breather tube is to allow air pressure to stabilize during transportation of skylights and windows. Because these tubes are hollow they must be crimped (closed) after or just before installation to keep moisture from forming between the panes of glass. If these breather tubes are not closed properly it could void the glass manufacturers’ warranty.