Triple pipe low temperature pipeline

Claim 2

A pipe section for use in a pipeline system comprising: a first pipe, a second pipe radiallyspaced from said first pipe in coaxial relation and connected therewith to define a first annulus therebetween, a third pipe connected in coaxial radially-spaced relation with said second pipe for restraining movement thereof and defining a second annulus therebetween, radial rib means connected between said first and second pipes and between said second and third pipes respectively, for interlocking said coaxial pipes to minimize thermal movement of said system and substantially eliminate axial differential thermal movement between said pipes, and insulation means disposed in said second annulus.

Claim 3

The pipe section of claim 1 wherein said rib means are connected to said first and second pipes and said second and third pipes respectively, at the end of said pipe section in axially spaced relationship.

Claim 4

The pipe section of claim 1 including intermediate rib means radially disposed between said first and second pipes, said intermediate rib means connected to at least one of said first and second coaxial pipes for preventing transverse radial buckling of said second pipe.

Claim 5

The pipe section of claim 3 wherein said intermediate rib means is connected at only one radial end thereof to said first pipe and at the opposite radial end thereof is in sliding relationship with said second pipe.

Claim 6

the pipe section of claim 1 including a concrete layer secured to an surrounding said third pipe.

Claim 7

A triple pipe counter flow system for use in a pipeline comprising: an inner pipe, a middle pipe and an outer casing all in coaxial relationship relative to each other, said middle pipe being radially spaced from said inner pipe and secured thereto by means of a first plurality of radial ribs for preventing relative axial movement between said pipes, said outer casing being radially spaced from said middle pipe and secured thereto by means of a second plurality of radial ribs for preventing relative axial movement therebetween, insulation means disposed in the radial spacing between said middle pipe and said outer casing, said first and second plurality of radial ribs being secured at opposite radial ends thereof to said pipes and said outer casing, thereby substantially eliminating differential axial thermal movement between said inner and middle pipes and said outer casing.

Claim 8

A triple pipe counter flow system for use in a pipeline comprising: an inner pipe, a middle pipe and an outer casing all in coaxial relationship relative to each other, said middle pipe being radially spaced from said inner pipe and secured thereto by means of a first plurality of radial ribs for preventing relative axial movement between said pipes, said outer casing being radially spaced from said middle pipe and secured thereto by means of a second plurality of radial ribs for preventing relative axial movement therebetween, insulation means disposed in the radial spacing between said middle pipe and said outer casing, said first and second plurality of radial ribs being secured at opposite radial ends thereof to said pipes and said outer casing, thereby substantially eliminating differential axial thermal movement between said inner and middle pipes and said outer casing.

Claim 9

The pipe system of claim 6 wherein said first and second plurality of radial ribs are peripherally spaced between said inner pipe and said middle pipe and between said middle pipe and said outer casing.

Claim 10

The pipe system of claim 6 including additional rib means between said middle pipe and said inner pipe for preventing radial buckling of said middle pipe.

Claim 11

The pipe system of claim 7 wherein each of said first and second radial ribs are located between adjacent ones of said second and first radial ribs, respectively.