A coupling body provided with a first supply conduit for receiving a first fuel fluid and a first discharge conduit for discharging the first fuel fluid, said first supply conduit in the coupling body being connected to the first discharge conduit in order to form a first fluid connection for the first fuel fluid from the first supply conduit to the first discharge conduit, wherein the coupling body is provided with a receiving chamber, wherein the first supply conduit is connected to the receiving chamber, the first discharge conduit is connected to the receiving chamber, and a coupling member is arranged in the receiving chamber, wherein the coupling member and the receiving chamber cooperate in order to form the first fluid connection, wherein the coupling body is provided with a second supply conduit for receiving the first or a second fuel fluid and with a second discharge conduit for discharging the first and/or the second fuel fluid, wherein the second supply conduit is connected to the receiving chamber, the second discharge conduit is connected to the receiving chamber, and wherein the coupling member and the receiving chamber cooperate in order to form a second fluid connection, wherein the second fluid connection connects the second supply conduit and the second discharge conduit to one another, wherein the first and second discharge conduit can be connected to a common connection with a fuel discharge line and wherein the coupling body is provided with a mixing chamber which is arranged directly upstream from said common connection.