Patent ID: 8474647

Claim:
A liner for a composite reinforced high pressure gas tank comprising: a metal tube that is seamless and integrally formed as a single unitary base piece, comprising: a cylindrical sidewall having a substantially constant diameter; a top end comprising: a top transition zone contoured to seamlessly transition between the cylindrical sidewall and the extended cylindrical neck, an extended cylindrical neck with an opening, and a substantially variable diameter narrowing along said top transition zone from the cylindrical sidewall to the extended cylindrical neck; and, a bottom end having a bottom transition zone contoured to seamlessly transition from said cylindrical sidewall to a distal end; a seamless top metal end cap integrally formed as a first single unitary overlay piece, said top metal end cap comprising an inner surface and an outer surface with solid metal therebetween, wherein the entire inner surface is in direct contact with the top end, wherein the top metal end cap overlays the top transition zone and a top portion of said cylindrical sidewall; and, a seamless bottom metal end cap integrally formed as a second single unitary overlay piece, said bottom metal end cap overlays the bottom end and a bottom portion of said cylindrical sidewall.