A coupling body having an opening and configured to receive a pipe in the opening. The coupling body is made of a metal material and the pipe is made of a different metal material to the metal material of the coupling body. An insulating sleeve lines at least a portion of an inner periphery of the coupling body adjacent the opening. The insulating sleeve is made of non-metallic material and is configured to serve as a physical non-metallic barrier between the metal material of the coupling and the different metal material of the pipe so the different metal material of the pipe does not contact the metallic material of the coupling body.