Method of forming a connection between two sealed condiutsusing radiant energy

A connection may be formed between sealed conduits in which each conduit carries an opaque, thermoplastic wall portion preferably having a melting range above essentially 200 DEG C., preferably with the opaque thermoplastic wall portions being carried on the conduit about their periphery by transparent wall portions of the conduit. The opaque wall portions of the conduits are brought together into facing contact, and then exposed to sufficient radiant energy to cause the opaque wall portions to fuse together, and to open an aperture through the fused wall portions. This provides sealed communication between the interiors of the conduits.