The present invention relates to a system for transporting and storing a liquid and for transporting said liquid from the container to a destination outside of the container. The system comprises a container with a neck portion, a cap assembly secured on the neck portion and a coupler assembly configured to be mechanically coupled to the cap assembly for a liquid connection to and/or from the container, comprising a male probe to be connected to a female part of the cap assembly. The female part has an essentially cylindrical body defining an axial bore extending from an insert opening for the male probe to an opposed plug opening for a plug which serves to close off the bore fluid-tight. According to the invention, a seal cover is provided over the bore, essentially parallel to the plug, which serves to close off the bore airtight.