Methods of using induction heating and moisture barriers to perform in-service pipeline maintenance

1 . A method of welding a tee fitting to a pipeline, comprising:

providing the pipeline, wherein the pipeline includes an upstream pipeline portion, a downstream pipeline portion, and the pipeline contains a product; and

providing a tee fitting, wherein the tee fitting includes two or more tee fitting pieces, including a first piece and a second piece, wherein the first piece includes a first piece nozzle including a first piece nozzle opening, a first piece bottom edge, a first piece upstream side edge, a first piece downstream side edge, and wherein the second piece includes a second piece top edge, a second piece upstream side edge, and a second piece downstream side edge, wherein the first piece bottom edge has a shape that fits or complements the second piece top edge; and

forming an upstream circumferential seam by bringing the first piece upstream side edge and the second piece upstream side edge into contact with the upstream pipeline portion, and forming a downstream circumferential seam by bringing the first piece downstream side edge and the second piece downstream side edge into contact with the downstream pipeline portion; and

forming a longitudinal seam by bringing the first piece bottom edge into contact with the second piece top edge; and

positioning a moisture absorbing material between the first piece nozzle opening and the pipeline; and

sealing the first piece nozzle opening with a nozzle moisture barrier; and

heating at least a portion of the first piece bottom edge and the second piece top edge to a longitudinal instillation temperature by induction heating; and

seam welding at least a portion of the longitudinal seam; and

forming an upstream moisture seal by covering the upstream circumferential seam with an upstream moisture barrier; or

forming a downstream moisture seal by covering the downstream circumferential seam with a downstream moisture barrier; or

any combination thereof.

2 . The method of claim 1 , further comprising;

removing the upstream moisture seal; and

heating the upstream circumferential seam by induction heating the first piece upstream edge, the second piece upstream edge, or both, to an upstream circumferential instillation temperature; and

circumferential welding the upstream circumferential seam; or

removing the downstream moisture seal; and

heating the downstream circumferential seam by induction heating the first piece downstream edge, the second piece downstream edge, or both, to a downstream circumferential instillation temperature; and

circumferential welding the downstream circumferential seam; or

tack welding the longitudinal seam before seam welding the longitudinal seam; or

any combination thereof.

3 . The method of claim 1 , wherein the pipeline has an internal diameter of about 30.5 cm to about 152.4 cm; or

wherein the product flows from an upstream direction to a downstream direction within the pipeline; or

wherein the product is flowing from an upstream direction to a downstream direction within the pipeline at a flow rate of from about 4.6 m/s to about 30.5 m/s; or

wherein the product has a product temperature, and the pipeline has a pipeline temperature below a weld proceed preheat requirement temperature; or

any combination thereof.

4 . The method of claim 1 ,

further comprising:

wherein seam welding the longitudinal seam, includes a first welding duration of from about 4 to about 12 hours, and then

removing the upstream moisture seal, the downstream moisture seal, or both, and then

seam welding the longitudinal seam for a second welding duration of from about 4 hours to about 12 hours; or

further comprising:

wherein seam welding the longitudinal seam, includes a first welding duration of from about 4 to about 12 hours, and then

removing the upstream moisture seal, the downstream moisture seal, or both, and then

seam welding the longitudinal seam for a second welding duration of from about 4 hours to about 12 hours, wherein the first welding duration and the second welding duration are separated by a cooling duration of about 4 hours to about 6 hours; or

wherein first seam welding duration, the second welding duration, and the cooling duration have an aggregate longitudinal seam welding duration of about 12 to about 26 hours; or

wherein seam welding the longitudinal seam, includes a first welding duration of from about 4 to about 12 hours, and then forming or re-forming the upstream moisture seal, the downstream moisture seal, or both, during a cooling duration, and then

removing the upstream moisture seal, the downstream moisture seal, or both, and then

seam welding the longitudinal seam for a second welding duration of from about 4 hours to about 12 hours; or

any combination thereof.

5 . The method of claim 2 , further comprising:

heating at least a portion of the first piece bottom edge, the second piece top edge, or any combination thereof, by induction heating from ambient temperature to about 121° C. to about 176° C. during a longitudinal preheating duration of about 10-30 minutes; or

heating at least a portion of the first piece upstream edge, the second piece upstream edge, or any combination thereof, by induction heating from ambient temperature to about 121° C. to about 176° C. during an upstream preheating duration of about 10-30 minutes; or

heating at least a portion of the first piece downstream edge, the second piece downstream edge, or any combination thereof, by induction heating from ambient temperature to about 121° C. to about 176° C. during a downstream preheating duration of about 10-30 minutes; or

wherein the longitudinal instillation temperature, the upstream circumferential instillation temperature, or the downstream circumferential instillation temperature, or any combination thereof, is from about 121° C. to about 176° C., wherein the longitudinal instillation temperature, the upstream circumferential instillation temperature, or the downstream circumferential instillation temperature is a surface temperature of a portion the first piece or the second piece, or any combination thereof; or

wherein the induction heating source is operated at a power of from about 15 kW to about 120 KW, at a frequency of 3 kHz to about 10 kHz or both; or

wherein the induction heating source includes a metal wire enclosed within a rubber tubing, and wherein water flows between the metal wire and an interior of the rubber tubing; or

any combination thereof.

6 . The method of claim 2 , further comprising;

reducing an amount of moisture under the tee fitting to mitigate the risk of hydrogen induced cracking in the upstream circumferential seam by forming or maintaining an upstream moisture seal during seam welding at least a portion of the longitudinal seam, circumferential welding the downstream circumferential seam, or both; or

reducing an amount of moisture under the tee fitting to mitigate the risk of hydrogen induced cracking in the downstream circumferential seam by forming or maintaining an downstream moisture seal during seam welding at least a portion of the longitudinal seam, circumferential welding the upstream circumferential seam, or both; or

any combination thereof.

7 . The method of claim 1 , wherein the moisture absorbing material includes a solid desiccant in an open container; or

wherein the moisture absorbing material includes a silica gel, a clay, calcium chloride, sodium chloride, potassium chloride, calcium sulfate, calcium oxide, or any combination or mixture thereof; or

wherein the moisture barrier includes a single homogenous film or membrane; or

wherein the moisture barrier includes a polymer film, a wax paper, a polyolefin film, a polyvinyl chloride film, a polyethylene film, a paraffin film, a polyvinylidene chloride film, a tape, or any combination thereof; or any combination thereof.

8 . A method of welding a tee fitting to a pipeline, comprising:

providing the pipeline, wherein the pipeline includes an upstream pipeline portion, a downstream pipeline portion, and the pipeline contains a product; and

providing a tee fitting, wherein the tee fitting includes 2 or more tee fitting pieces, including a first piece and a second piece, wherein the first piece includes a first piece bottom edge, a first piece upstream side edge, a first piece downstream side edge, and wherein the second piece includes a second piece top edge, a second piece upstream side edge, and a second piece downstream side edge, wherein the first piece bottom edge has a shape that fits or complements the second piece top edge; and

forming an upstream circumferential seam by bringing the first piece upstream side edge and the second piece upstream side edge into contact with the upstream pipeline portion, and forming a downstream circumferential seam by bringing the first piece downstream side edge and the second piece downstream side edge into contact with the downstream pipeline portion; and

forming a longitudinal seam by bringing the first piece bottom edge into contact with the second piece top edge; and

heating at least a portion of the first piece bottom edge and the second piece top edge to a longitudinal instillation temperature by induction heating; and

seam welding at least a portion of the longitudinal seam; and

forming an upstream moisture seal by covering the upstream circumferential seam with an upstream moisture barrier; or

forming a downstream moisture seal by covering the downstream circumferential seam with a downstream moisture barrier; or

any combination thereof.

9 . The method of claim 8 , further comprising;

removing the upstream moisture seal; and

heating the upstream circumferential seam by induction heating the first piece upstream edge, the second piece upstream edge, or both, to an upstream circumferential instillation temperature; and

circumferential welding the upstream circumferential seam; or

removing the downstream moisture seal; and

heating the downstream circumferential seam by induction heating the first piece downstream edge, the second piece downstream edge, or both, to a downstream circumferential instillation temperature; and

circumferential welding the downstream circumferential seam; or

tack welding the longitudinal seam before seam welding the longitudinal seam; or

any combination thereof.

10 . The method of claim 8 , wherein the pipeline has an internal diameter of about 30.5 cm to about 152.4 cm; or

wherein the product flows from an upstream direction to a downstream direction within the pipeline; or

wherein the product is flowing from an upstream direction to a downstream direction within the pipeline at a flow rate of from about 4.6 m/s to about 30.5 m/s; or

wherein the product has a product temperature, and the product temperature is below an ambient temperature; or

any combination thereof.

11 . The method of claim 8 ,

further comprising:

wherein seam welding the longitudinal seam, includes a first welding duration of from about 4 to about 12 hours, and then

removing the upstream moisture seal, the downstream moisture seal, or both, and then

seam welding the longitudinal seam for a second welding duration of from about 4 hours to about 12 hours; or

further comprising:

wherein seam welding the longitudinal seam, includes a first welding duration of from about 4 to about 12 hours, and then

removing the upstream moisture seal, the downstream moisture seal, or both, and then

seam welding the longitudinal seam for a second welding duration of from about 4 hours to about 12 hours, wherein the first welding duration and the second welding duration are separated by a cooling duration of about 4 hours to about 6 hours; or

wherein first seam welding duration, the second welding duration, and the cooling duration have an aggregate longitudinal seam welding duration of about 12 to about 26 hours; or

wherein seam welding the longitudinal seam, includes a first welding duration of from about 4 to about 12 hours, and then forming or re-forming the upstream moisture seal, the downstream moisture seal, or both, during a cooling duration, and then

removing the upstream moisture seal, the downstream moisture seal, or both, and then

seam welding the longitudinal seam for a second welding duration of from about 4 hours to about 12 hours; or

any combination thereof.

12 . The method of claim 9 , further comprising:

heating at least a portion of the first piece bottom edge, the second piece top edge, or any combination thereof, by induction heating from ambient temperature to about 121° C. to about 176° C. during a longitudinal preheating duration of about 10-30 minutes; or

heating at least a portion of the first piece upstream edge, the second piece upstream edge, or any combination thereof, by induction heating from ambient temperature to about 121° C. to about 176° C. during an upstream preheating duration of about 10-30 minutes; or

heating at least a portion of the first piece downstream edge, the second piece downstream edge, or any combination thereof, by induction heating from ambient temperature to about 121° C. to about 176° C. during a downstream preheating duration of about 10-30 minutes; or

wherein the longitudinal instillation temperature, the upstream circumferential instillation temperature, or the downstream circumferential instillation temperature, or any combination thereof, is from about 121° C. to about 176° C., wherein the longitudinal instillation temperature, the upstream circumferential instillation temperature, or the downstream circumferential instillation temperature is a surface temperature of a portion the first piece or the second piece, or any combination thereof; or

wherein the induction heating source is operated at a power of from about 15 kW to about 120 KW, at a frequency of 3 kHz to about 10 kHz or both; or

wherein the induction heating source includes a metal wire enclosed within a rubber tubing, and wherein water flows between the metal wire and an interior of the rubber tubing; or

any combination thereof.

13 . The method of claim 9 , further comprising;

reducing an amount of moisture under the tee fitting to mitigate the risk of hydrogen induced cracking in the upstream circumferential seam by forming or maintaining an upstream moisture seal during seam welding at least a portion of the longitudinal seam, circumferential welding the downstream circumferential seam, or both;

reducing an amount of moisture under the tee fitting to mitigate the risk of hydrogen induced cracking in the downstream circumferential seam by forming or maintaining a downstream moisture seal during seam welding at least a portion of the longitudinal seam, circumferential welding the upstream circumferential seam, or both; or

any combination thereof.