Abstract: A liquid transport system has a number of access points, referred to generally as nodes, connected to an endless loop of piping such that liquid flowing in the system, to move the liquid from one node to another, flows in two generally discrete paths from a source node to a destination node. In general, any node can be associated with either a liquid source or a liquid destination. A source in a first liquid transfer can act as a destination in a subsequent liquid transfer, and vice versa. A single pigging system can be used to clean substantially the entirety of the liquid transport system among all sources and all destinations, except for leads from the nodes to the sources and/or destinations. The liquid transport system can be cleaned in place, thus to clean all of the piping which runs between the respective nodes in the liquid transport system.