A fuel cylinder, such as a high-pressure fluid storage tank, is provided with dual-inlet refilling capabilities. The storage tank may include a main body section with a first domed end portion and a second domed end portion disposed at opposite portions of the main body section. A first inlet assembly and a second inlet assembly are provided at the respective first domed end portion and the second domed end portion. Each inlet assembly is configured to provide fluid communication between a supply of a high-pressure fluid and an interior of the storage tank. Each inlet assembly may include a boss and a tank valve, with each tank valve being in fluid communication with the compressed fluid receptacle. During filling of the storage tank, the high-pressure fluid travels through a compressed fluid receptacle and enters the interior of the storage tank simultaneously through each of the first and second inlet assemblies.