Jacketed pipeline system with pressurized gas to resist external stress

Claim 2

A pipeline system capable of withstanding an external pressure, comprising: a pipe; an outer pipe jacket surrounding and spaced from said pipe to define an annulus; insulation material located in said annulus so as to encase said pipe; and a volume of gas which is chemically inert with respect to said pipe, said pipe jacket, and said insulation material located in said annulus at a pressure greater than the external pressure on said jacket, said gas selected so that it will not condense at its pressure in the system while adding minimally to the thermal conductivity of the system.

Claim 3

The pipeline system of claim 1 further comprising a vapor barrier encasing and adhering to said insulation material to prevent said volume of gas from penetrating said insulation material and said pipe.

Claim 4

The pipeline system of claim 1 wherein said gas is supplied and maintained in said annulus at a selected pressure by a supply tank, a pressure regulator, and a gas flowmeter.

Claim 5

A pipeline system capable of withstanding an external pressure, comprising: a pipe; insulation material encasing said pipe; a vapor barrier encasing and adhering to said insulation material to prevent said volume of gas from penetrating said insulation material and said pipe; an outer pipe jacket surrounding and spaced from said pipe to define an annulus; and a volume of gas which is chemically inert with respect to said pipe, said pipe jacket, and said insulation material located in said annulus having a pressure greater than the external pressure incident at the exterior surface of said jacket, said gas elected so that it will not condense at its pressure in the system while adding minimally to the thermal conductivity of the system.

Claim 6

A pipeline system capable of withstanding an external pressure, comprising: a pipe; insulation material encasing said pipe; a vapor barrier encasing and adhering to said insulation material to prevent said volume of gas from penetrating said insulation material and said pipe; an outer pipe jacket surrounding and spaced from said pipe to define an annulus; and a volume of gas which is chemically inert with respect to said pipe, said pipe jacket, and said insulation material located in said annulus having a pressure greater than the external pressure incident at the exterior surface of said jacket, said gas elected so that it will not condense at its pressure in the system while adding minimally to the thermal conductivity of the system.

Claim 7

The pipeline system of claim 4 wherein said gas is supplied and maintained in said annulus at a selected pressure by a supply tank, a pressure regulator, and a gas flowmeter.