System, apparatus and method for opening a heat-bonded connection (32) formed between two hollow, flexible thermoplastic conduits (20, 22). A pressure difference is created between the inside of at least one of the conduits (20, 22) and the ambient atmosphere sufficient to cause expansion of a wall of the tubing conduit (38) in the vicinity of a frangible portion at least partially blocking the connection to disrupt the frangible portion and reduce the blocking.