Process and apparatus for repairing pipes
View Patent ↗A two-stage process for repairing pipes at elevated temperatures and at elevated pressure. The process comprises the steps of preparing and displacing a hose assembly within the pipeline needing repair. A pressure medium is then introduced into the hose assembly raising the first temperature to initiate and facilitate the cross-linking reaction, and then raising the temperature to a second temperature range and pressure to cure or harden the resin. Novel manifolds and access tubes which allow the practicing the process safely are also provided.
1. A process of lining a pipe, the process comprising the steps of:
a. isolating a segment of pipe requiring relining;
b. preparing a hose assembly, the hose assembly comprising a flexible liner impregnated within a resin;
c. introducing the hose assembly into the segment of pipe requiring relining;
d. expanding the hose assembly so that the hose assembly contacts an inner surface of the pipe by injecting a heated pressurized medium into the hose assembly;
e. elevating the temperature of the hose assembly to a first temperature range to allow for cross-linking the resin;
f. elevating the temperature of the hose assembly to a second temperature range;
g. maintaining the temperature of the hose assembly within the second temperature range for a selected time to allow curing of the resin; and
h. cooling the hose assembly.
2. The process of claim 1 , wherein the hose assembly further comprises a calibration hose, the calibration hose being placed within the flexible liner in a generally parallel position.
3. The process of claim 1 , before inserting the heated pressure medium, further comprising the step of removably attaching a plurality of thermocouples to selected locations on the inner surface of the segment of pipe.
4. The process of claim 1 , wherein the medium comprises a liquid.
5. The process of claim 1 , wherein the medium comprises a gas.
6. The process of claim 1 , wherein the medium comprises steam.
7. The process of claim 1 , wherein the medium comprises air.
8. The process of claim 1 , wherein the volume of the medium is increased in the hose assembly to elevate the temperature to the first temperature range.
9. The process of claim 1 , wherein the volume of gas within the hose assembly is increased to elevate the temperature to the first temperature range.
10. She process of claim 1 , wherein the resin is selected from the group consisting of a polyester, a vinyl ester or an epoxy resin, and any combination thereof.
11. The process of claim 1 , whereas the resin is styrenated or non-styrenated.
12. The process of claim 1 , wherein the volume of the heated pressure medium is increased to elevate the temperature of the hose assembly to the second temperature range.
13. The process of claim 1 , wherein the first temperature range is from about 110 degrees Fahrenheit to about 200 degrees Fahrenheit.
14. The process of claim 1 , wherein the selected pressure range is about 15 pounds per square inch.
15. The process of claim 1 , wherein the highest temperature of the second temperature range is no greater than about 300 degrees Fahrenheit.
16. The process of claim 1 , wherein the lowest temperature of the second temperature range is at least about 150 degrees Fahrenheit.
17. The process of claim 1 , wherein the lowest temperature of the second temperature range is at least about 170 degrees Fahrenheit.
18. The process of claim 1 , wherein the lowest temperature of the second temperature range is at least about 190 degrees Fahrenheit.
19. The process of claim 1 , wherein the lowest temperature of the second temperature range is at least about 210 degrees Fahrenheit.
20. The process of claim 1 , wherein the hose assembly is maintained at the second temperature range for a selected time.
21. The process of claim 20 , wherein the selected time is dependent upon a lowest temperature monitored at the plurality of thermocouples.
22. The process of claim 20 , wherein the selected time is greater than about five minutes.
23. The process of claim 20 , wherein the selected time is greater than about ten minutes.
24. The process of claim 20 , wherein the selected time is less than about one hundred and forty minutes.
25. The process of claim 20 , wherein the selected time is less than about seventy minutes.
26. The process of claim 1 , further comprising the step of monitoring the thermocouples while evacuating the heated pressure medium until all measure temperatures of less than about 100 degree Fahrenheit.
27. The process of claim 1 , further comprising the step of continuously introducing the heated pressure medium into the hose assembly while maintaining the hose assembly within the first and second temperature ranges.
28. The process of claim 1 , further comprising the step of inserting a collection tube into the flexible liner before the step of introducing the heated pressure medium to allow moisture to be collected and drained from the hose assembly.
29. A process of lining a pipe, the process comprising the steps of:
a. isolating a segment of a pipe requiring relining, the pipe having an inner surface;
b. preparing a hose assembly, the hose assembly comprising a flexible liner impregnated with a resin;
c. introducing the hose assembly into the segment of pipe requiring relining;
d. removably attaching a plurality of thermocouples to selected locations on the inner surface of the segment of pipe;
e. removably securing a first manifold to the first end of the hose assembly and removably securing a second manifold to the second end of the hose assembly;
f. expanding the hose assembly so that the flexible liner contacts the inner surface of the pipe by injecting a heated pressurized medium into the hose assembly;
g. elevating the temperature of the hose assembly to a first temperature range to allow for cross-linking the resin;
h. monitoring the thermocouples until the cross-linking reaction exothermss;
i. elevating the temperature of the hose assembly to a second temperature range;
j. maintaining the temperature of the hose assembly within the second temperature range for a selected time sufficient to allow for the curing of the resin; and
k. cooling the hose assembly.