A pressure vessel for storage and transportation of CNG comprises a body, which defines an internal volume in which the CNG is stored and transported. An inlet is provided through which the CNG can be loaded into the internal volume of the vessel. At the end of said inlet there is a CNG expansion section through which the CNG expands into the vessel when loaded. The pressure vessel further comprises a CNG loading appendage for injecting the CNG at a point inside the internal volume of the vessel, thereby increasing the space between the expansion point of the CNG and the walls of the vessel.