A method electrically separates two fluid lines across a structural boundary. Fluid is transported between a first channel through a first fluid line and a second channel through a second fluid line across the structural boundary formed by a structure. The first channel and the second channel are connected by a channel formed by a fitting. The fitting is comprised of a first component, a second component, and an isolator. The first fluid line and the second fluid line are electrically separated using the isolator in the fitting.