Pressure vessel and process for producing the same

A process for producing a pressure vessel characterised in forming, by a filament winding method or a tape winding method, a pressure resistant outer shell, around an inner shell capable of serving as a gas barrier, said outer shell is made of an CFRP comprising reinforcing carbon fibers having a strand tensile breaking strain of 2.0% or more and a resin and is 35 GPa or more in tensile modulus and 1.5% or more in tensile breaking strain,

• wherein
• the outer shell comprises a first layer of reinforcing fibers arranged, with reference to the axial direction of the pressure vessel, at an angle within a range from 10 degrees to ±15 degrees, a second layer of reinforcing fibers arranged at an angle within a range from ±85 degrees to ±100 degrees and a third layer of reinforcing fibers arranged at an angle within a range from ±40 degrees to ±60 degrees and wherein the volume ratio of reinforcing fibers in the first layer of reinforcing fibers arranged at an angle within a range from ±0 degrees to ±15 degrees to that in the second layer in the reinforcing fibers arranged at an angle within a range from ±85 degrees to ±100 degrees to that in the third layer of reinforcing fibers arranged at an angle within a range from ±40 degrees to ±60 degrees, with reference to the axial direction of the pressure vessel, is within a range of 1:1:5:0.2 to 1:2.5:1.2.