Method for coupling corrugated pipe segments

1. A method for coupling pipe segments comprising:

providing first and second thermoplastic corrugated pipe segments arranged to form a fluid flow path therethrough;

aligning ends of the first and second pipe segments adjacent one another to form a joint;

providing a coupling assembly comprising a thermoplastic sheet having a flexible weld rod comprising a thermoplastic material attached to an outer surface of the thermoplastic sheet;

circumferentially contacting the first and second thermoplastic pipe segments with the coupling assembly; and

applying an electrical current to the weld rod to cause the weld rod, sheet and pipe segments to fuse to one another and form a circumferential weld seam on each side of the joint.

2. The method of claim 1 , wherein the step of providing pipe segments further comprises providing a corrugated pipe segment having a smooth interior surface.

3. The method of claim 1 , wherein the step of providing a coupling assembly further comprises providing a plurality of corrugation alignment tabs attached to the sheet.

4. The method of claim 3 , wherein the corrugation alignment tabs are formed integral with the sheet.

5. The method of claim 1 , wherein the sheet, the weld rod and the pipe segments all comprise a same material.

6. The method of claim 5 , wherein the same material is high density polyethylene or polypropylene.

7. The method of claim 1 , further comprising the step of exerting a continuous force to maintain compression between the coupling assembly and the pipe segments during the step of applying an electrical current.

8. The method of claim 7 , wherein the step of exerting a continuous force to maintain compression is achieved by at least one strap wrapped around the coupling assembly.

9. The method of claim 1 , wherein the step of circumferentially contacting comprises wrapping the coupling assembly around an external surface of the pipe segments.

10. The method of claim 1 , wherein the step of circumferentially contacting comprises wrapping the coupling assembly about an internal surface of the pipe segments.

11. The method of claim 1 , wherein the step of circumferentially contacting further comprises covering at least one corrugation on each of the first and second pipe segments.

12. The method of claim 1 , wherein the weld rod is attached to the sheet by thermoforming.

13. The method of claim 1 , wherein the thickness of corrugation elements of the first and second pipe segments are each of about the same thickness as the sheet.

14. The method of claim 13 , wherein the thickness of corrugation elements of the first and second pipe segments and the sheet is about ⅛ inch.

15. The method of claim 1 , wherein the weld rod comprises an elongate thermoplastic material having at least one resistance wire embedded therein.

16. The method of claim 1 , wherein the steps of circumferentially contacting and applying are carried out while at least one of the pipe segments is situated within a trench.

17. A method for coupling pipe segments comprising:

providing first and second thermoplastic pipe segments arranged to form a fluid flow path therethrough;

aligning ends of the first and second pipe segments adjacent one another to form a joint;

providing a coupling assembly comprising a thermoplastic sheet having a flexible weld rod comprising a thermoplastic material attached to an outer surface of the thermoplastic sheet, the sheet having a thickness that is about the same as that of corrugation elements of each of the first and second pipe segments;

circumferentially contacting the first and second thermoplastic pipe segments with the coupling assembly by wrapping the coupling assembly about an internal surface of the first and second pipe segments such that the weld rod encircles the inner surface of the pipe segments on each side of the joint and the weld rod is in contact with the sheet and the internal surface of the pipe segments; and

while exerting a continuous force to maintain compression between the coupling assembly and the internal surface of the pipe segments, applying an electrical current to the weld rod to cause the weld rod, sheet and pipe segments to fuse to one another and form a circumferential weld seam on each side of the joint.

18. The method of claim 17 , wherein the continuous force to maintain compression is achieved by at least one strap wrapped around the coupling assembly.

19. A method for coupling pipe segments comprising:

providing first and second thermoplastic corrugated pipe segments arranged to form a fluid flow path therethrough;

aligning ends of the first and second pipe segments adjacent one another to form a joint;

providing a coupling assembly comprising a thermoplastic sheet having a flexible weld rod comprising a thermoplastic material attached thereto and further comprising a plurality of corrugation alignment tabs attached to the sheet, the sheet having a thickness that is about the same as that of corrugation elements of each of the first and second pipe segments;

circumferentially contacting the first and second thermoplastic pipe segments with the coupling assembly by wrapping the coupling assembly around an external surface of the first and second pipe segments such that the weld rod encircles the pipe segment on each side of the joint and the weld rod is in contact with the sheet and the external surface of the pipe segments and such that at least one corrugation alignment tab is disposed within a valley between adjacent corrugations of the first pipe segment and at least one corrugation alignment tab is disposed within a valley between adjacent corrugations of the second pipe segment; and

while exerting a continuous force to maintain compression between the coupling assembly and the external surface of the pipe segments, applying an electrical current to the weld rod to cause the weld rod, sheet and pipe segments to fuse to one another and form a circumferential weld seam on each side of the joint.

20. The method of claim 19 , wherein the corrugation alignment tabs are formed integral with the sheet.