When a low conductivity liquid, such as a hydrocarbon, flows through a metal pipe, an axial streaming current is generated and convected along the pipe into a collection vessel. Because the conductivity is so low, little upstream migration current occurs, and a potential difference arises between the pipe and the receiving vessel. This potential difference drives a return current along any electrical connection between the pipe and the vessel. Extensive measurements have been made of this ''flow electrification'', since it causes explosion hazards in the petroleum industry [1-6]. Likewise a large number of semi-empirical models are available for both laminar and turbulent flow [1-8]. To date, however, no self-consistent theory exists to explain the flow electrification phenomenon based on accepted electrochemical principles.