Sealing rings for the ends of heat-insulated pipe units

Claim 2

An elastomeric sealing ring for sealing the end of a heat-insulated pipe unit of the kind having a pipe surrounded by a layer of heat-insulating material in turn enclosed in an outer jacket of fluid impervious material, the ring being of generally U-shaped cross-section, comprising a relatively thin radially disposed base part, an inner tubular flange projecting axially in one direction from the inner margin of one main surface of the base part and having a cylindrical inner surface for engaging the outer surface of the respective projecting pipe end part of the pipe unit, an outer tubular flange projecting in said one direction from the outer margin of said one main surface of the base part coaxially with respect to said inner tubular flange the thickness of said flanges at their junction with the base part being greater than the thickness of said base part, said base part and said outer tubular flange being formed with a parallel-sided annular groove for receiving the respective jacket end part of the pipe unit, said annular groove extending axially from the opposite main surface of said base part for a substantial distance into the interior of the outer tubular flange, so that said outer tubular flange has an inner portion extending inside said annular groove in said one direction away from said base part and integrally connected, at that end of the outer tubular flange which is remote from said base part, with an outer portion extending outside said annular groove in the opposite direction back towards said base part.

Claim 3

A sealing ring as claimed in claim 1, wherein the end of said outer portion of said outer tubular flange which is nearer to the base part is thickened so as to provide an externally projecting rim part.

Claim 4

A sealing ring as claimed in claim 1 in which the cross-sectional thickness of said relatively thin base part of said U-cross-section sealing ring is less than the mean thickness of the inner tubular flange and the radial extent of said base part exceeds by several times the radial extent of said annular groove.

Claim 5

A sealing ring as claimed in claim 1 in which said base part is thinner and thereby more flexible than the adjoining parts of the inner and outer tubular flanges.

Claim 6

In a heat-insulated pipe unit of the kind which comprises a pipe, at least one layer of heat-insulating foam material surrounding said pipe over the greater part of the length of said pipe and an outer jacket of fluid-impervious protective material, the end parts of the pipe projecting beyond the corresponding ends of the foam material and the ends of the jacket projecting likewise but for a shorter distance, so that annular recesses are provided in the ends of the pipe unit, the improvement composed by said pipe unit having at least one end thereof sealed by an elastomeric sealing ring of generally U-shaped cross-section located at least partly within the annular recess in the respective end of said pipe unit, said sealing ring comprising a relatively thin radially disposed base part, a radially inner tubular flange projecting axially from the inner margin of one main surface of the base part and having a cylindrical inner surface tightly engaged around the outer surface of the respective projecting pipe end part and an outer tubular flange projecting in the same direction as said inner flange from the outer margin of said one main surface of the base part coaxially with respect to said inner tubular flange the thickness of said flanges at their junction with the base part being greater than the thickness of said base part, said base part and said outer tubular flange being formed with a parallel-sided annular groove extending axially from the other main surface of said base part for a substantial distance into the interior of the outer tubular flange so that said outer tubular flange has an inner portion extending inside said annular groove in the direction away from said base part and integrally connected, at that end of the outer tubular flange which is remote from said base part, with an outer portion extending outside said annular groove in the direction towards said base part, said outer portion being tightly engaged around the outer surface of the respective projecting jacket end part of said pipe unit.

Claim 7

In a heat-insulated pipe unit of the kind which comprises a pipe, at least one layer of heat-insulating foam material surrounding said pipe over the greater part of the length of said pipe and an outer jacket of fluid-impervious protective material, the end parts of the pipe projecting beyond the corresponding ends of the foam material and the ends of the jacket projecting likewise but for a shorter distance, so that annular recesses are provided in the ends of the pipe unit, the improvement composed by said pipe unit having at least one end thereof sealed by an elastomeric sealing ring of generally U-shaped cross-section located at least partly within the annular recess in the respective end of said pipe unit, said sealing ring comprising a relatively thin radially disposed base part, a radially inner tubular flange projecting axially from the inner margin of one main surface of the base part and having a cylindrical inner surface tightly engaged around the outer surface of the respective projecting pipe end part and an outer tubular flange projecting in the same direction as said inner flange from the outer margin of said one main surface of the base part coaxially with respect to said inner tubular flange the thickness of said flanges at their junction with the base part being greater than the thickness of said base part, said base part and said outer tubular flange being formed with a parallel-sided annular groove extending axially from the other main surface of said base part for a substantial distance into the interior of the outer tubular flange so that said outer tubular flange has an inner portion extending inside said annular groove in the direction away from said base part and integrally connected, at that end of the outer tubular flange which is remote from said base part, with an outer portion extending outside said annular groove in the direction towards said base part, said outer portion being tightly engaged around the outer surface of the respective projecting jacket end part of said pipe unit.

Claim 8

A pipe unit as claimed in claim 5, wherein the tight engagement of the inner surface of said inner tubular flange of the sealing ring around the outer surface of the respective projecting pipe end part and of the inner surface of the outer portion of the outer tubular flange around the outer surface of the respective projecting jacket end part is due to the dimensions of the sealing ring being such that, in the relaxed state thereof, each of said inner surfaces is of smaller diameter than the respective one of said outer surfaces.

Claim 9

A pipe unit as claimed in claim 5, wherein the sealing ring is additionally secured and sealed with respect to the corresponding projecting jacket end part by a clamping ring comprising the outer and inner portions of the outer tubular flange of the sealing ring against the outer and inner surfaces respectively of said projecting jacket end part.

Claim 10

A pipe unit as claimed in claim 5, wherein the sealing ring is additionally secured and sealed with respect to the corresponding projecting end part by the outer surface of the projecting jacket end part being formed with serrations engaging in the inner surface of the outer portion of the outer tubular flange of the sealing ring.

Claim 11

A pipe unit as claimed in claim 5, wherein the sealing ring is additionally secured and sealed with respect to the corresponding projecting jacket end part by the projecting jacket end part having a thickened end portion engaging in a corresponding enlargement of the base part of the annular groove in the sealing ring.

Claim 12

A sealed heat-insulated joint between two heat-insulated pipe units, each of which pipe units comprises a pipe, at least one layer of heat-insulating foam material surrounding said pipe over the greater part of the length of said pipe and an outer jacket of fluid-impervious protective material, the end parts of the pipe projecting beyond the corresponding ends of the foam material and the ends of the jacket projecting likewise but for a shorter distance, so that annular recesses are provided in the ends of the pipe unit, said two pipe units being connected end-to-end by jointing means between juxtaposed projecting pipe end parts thereof, each of said pipe units having the end thereof which is nearer to the jointing means sealed by a respective elastomeric sealing ring of generally U-shaped cross-section located at least partly within the annular recess in the respective end of said pipe unit, said sealing ring comprising a relatively thin radially disposed base part, a radially inner tubular flange projecting axially from the inner margin of one main surface of the base part and having a cylindrical inner surface tightly engaged around the outer surface of the respective projecting pipe end part and an outer tubular flange projecting in the same direction as said inner flange from the outer margin of said one main surface of the base part coaxially with respect to said inner tubular flange the thickness of said flanges at their junction with the base part being greater than the thickness of said base part, said base part and said outer tubular flange being formed with a parallel-sided annular groove extending axially from the other main surface of said base part for a substantial distance into the interior of the outer tubular flange so that said outer tubular flange has an inner portion extending inside said annular groove in the direction away from said base part and integrally connected, at that end of the outer tubular flange which is remote from said base part, with an outer portion extending outside said annular groove in the direction towards said base part, said outer portion being tightly engaged around the outer surface of the respective projecting jacket end part of said pipe unit, the interconnected pipe end parts of the two pipe units being surrounded, at least in the region of said jointing means, by heat-insulating foam material and an outer cover of fluid-impervious material being provided over the outer surface of said heat-insulating foam material, over at least part of the outer surfaces of the outer tubular flanges of the sealing rings and over outer surface parts of the pipe unit jackets adjoining the sealing rings.

Claim 13

A sealed heat-insulated joint between two heat-insulated pipe units, each of which pipe units comprises a pipe, at least one layer of heat-insulating foam material surrounding said pipe over the greater part of the length of said pipe and an outer jacket of fluid-impervious protective material, the end parts of the pipe projecting beyond the corresponding ends of the foam material and the ends of the jacket projecting likewise but for a shorter distance, so that annular recesses are provided in the ends of the pipe unit, said two pipe units being connected end-to-end by jointing means between juxtaposed projecting pipe end parts thereof, each of said pipe units having the end thereof which is nearer to the jointing means sealed by a respective elastomeric sealing ring of generally U-shaped cross-section located at least partly within the annular recess in the respective end of said pipe unit, said sealing ring comprising a relatively thin radially disposed base part, a radially inner tubular flange projecting axially from the inner margin of one main surface of the base part and having a cylindrical inner surface tightly engaged around the outer surface of the respective projecting pipe end part and an outer tubular flange projecting in the same direction as said inner flange from the outer margin of said one main surface of the base part coaxially with respect to said inner tubular flange the thickness of said flanges at their junction with the base part being greater than the thickness of said base part, said base part and said outer tubular flange being formed with a parallel-sided annular groove extending axially from the other main surface of said base part for a substantial distance into the interior of the outer tubular flange so that said outer tubular flange has an inner portion extending inside said annular groove in the direction away from said base part and integrally connected, at that end of the outer tubular flange which is remote from said base part, with an outer portion extending outside said annular groove in the direction towards said base part, said outer portion being tightly engaged around the outer surface of the respective projecting jacket end part of said pipe unit, the interconnected pipe end parts of the two pipe units being surrounded, at least in the region of said jointing means, by heat-insulating foam material and an outer cover of fluid-impervious material being provided over the outer surface of said heat-insulating foam material, over at least part of the outer surfaces of the outer tubular flanges of the sealing rings and over outer surface parts of the pipe unit jackets adjoining the sealing rings.

Claim 14

A heat-insulated joint as claimed in claim 10, wherein end portions of the heat-insulating foam material surrounding the interconnected pipe ends parts of the two pipe units extend longitudinally over the outer surface parts of the outer tubular flanges of the sealing rings.

Claim 15

A heat-insulated joint as claimed in claim 10, wherein the end portions of the heat-insulating foam material surrounding the interconnected pipe end parts of the two pipe units projected into annular spaces defined by the inner and outer flanges of the sealing rings and each of said end portions has radially inner and outer surface parts engaging those ends of the inner and outer tubular flanges respectively of the corresponding sealing ring which are remote from the base part thereof, so as to limit axial movement of the sealing rings towards the jointing means.

Claim 16

A heat-insulated joint as claimed in claim 12, wherein said radially inner and outer surface parts of the end portions of said heat-insulating foam material are frusto-conical surface parts.

Claim 17

A heat-insulated joint as cliamed in claim 10, wherein said other main surface of the base part of each sealing ring is in contact with the proximate end surface of the heat-insulating foam material of the respective pipe unit and said one main surface of the base part of each sealing ring is in contact with the proximate end surface of the heat-insulating foam material surrounding the interconnected pipe end parts of the two pipe units.

Claim 18

A heat-insulated joint as claimed in claim 10, wherein said other main surface of the base part of each sealing ring is spaced from the proximate end surface of the heat-insulating foam material of the respective pipe unit and said one main surface of the base part of each sealing ring is spaced from the proximate end surface of the heat-insulating foam material surrounding the interconnected pipe end parts of the two pipe units.

Claim 19

A heat-insulated joint as claimed in claim 10, wherein the end parts of the outer cover are tightly secured to the respective pipe unit jackets by clamping rings fitted tightly around said end parts.

Claim 20

A heat-insulated joint as claimed in claim 10, wherein the end parts of the outer cover are tightly secured to the respective pipe unit jackets by tapes wound tightly round the said end parts of the outer cover and round axially adjoining outer surface parts of the respective pipe unit jackets.