A pressure vessel for containing liquids and/or gases under pressure, said pressure vessel comprising: a polymeric liner comprising a hollow body having a cylindrical wall extending from a first end to an opposing end of said liner, said cylindrical wall having an inner surface and an outer surface, said hollow body including a corrugated section having circumferential corrugations providing alternating ridges (140, 140') and valleys arranged from one end to an opposing end of said corrugated section, each of said corrugations comprising a curved mountain region having a ridge (140, 140'), a curved valley between adjacent spaced apart mountain regions, and a side wall (228, 228') joining each successive mountain region and valley, said outer surface of said ridge (140, 140') defining an outer diameter of the corrugated section, air space between said outer surface of adjacent side walls (228, 228') defining an annular cavity, a distance between successive ridges (140, 140') defines a period of said corrugations, a distance between said inner surface and said outer surface of said liner at said ridge (140, 140') defines a mountain wall thickness (Tm), a distance between said inner surface and said outer surface of said liner at a midpoint of said valley defines a valley wall thickness (Tv), and a radial distance between said outer surface at said ridge (140, 140') and said outer surface at said valley defines an amplitude of said corrugations; and an outer composite shell comprising resin and fiber surrounding an outer periphery of said liner; characterized in that: wherein said mountain wall thickness Tm is greater than said valley wall thickness Tv and said amplitude A is between about 0.65 times said period T and about 0.75 times said period T of said corrugations. a polymeric liner comprising a hollow body having a cylindrical wall extending from a first end to an opposing end of said liner, said cylindrical wall having an inner surface and an outer surface, said hollow body including a corrugated section having circumferential corrugations providing alternating ridges (140, 140') and valleys arranged from one end to an opposing end of said corrugated section, each of said corrugations comprising a curved mountain region having a ridge (140, 140'), a curved valley between adjacent spaced apart mountain regions, and a side wall (228, 228') joining each successive mountain region and valley, said outer surface of said ridge (140, 140') defining an outer diameter of the corrugated section, air space between said outer surface of adjacent side walls (228, 228') defining an annular cavity, a distance between successive ridges (140, 140') defines a period of said corrugations, a distance between said inner surface and said outer surface of said liner at said ridge (140, 140') defines a mountain wall thickness (Tm), a distance between said inner surface and said outer surface of said liner at a midpoint of said valley defines a valley wall thickness (Tv), and a radial distance between said outer surface at said ridge (140, 140') and said outer surface at said valley defines an amplitude of said corrugations; and an outer composite shell comprising resin and fiber surrounding an outer periphery of said liner; characterized in that: wherein said mountain wall thickness Tm is greater than said valley wall thickness Tv and said amplitude A is between about 0.65 times said period T and about 0.75 times said period T of said corrugations.