A system and method enable intelligent refuelling of a pressurised vessel. The method includes receiving a gas at a refuelling port, wherein the refuelling port is coupled to the pressure vessel; determining a temperature 5 of the pressure vessel; determining a pressure of the pressure vessel; directing the gas through a nozzle, wherein the pressure vessel and nozzle are thermally coupled such that Joule-Thomson expansion of a gas flowing through the nozzle cools an interior cavity of the pressure vessel; and controlling a shut-off valve according to an amount of gas in the pressure 10 vessel determined according to the temperature and pressure, wherein the shut-off valve is located between the refuelling port and the pressure vessel, for controlling a flow of gas between the refuelling port and the pressure vessel.