Method of everting a tube

Claims

1. In connection with tube eversion apparatus comprising a housing having an open top and open bottom through which a tube to be everted can pass, said housing comprising first and second chambers communicating with one another by a passage defined at least in part by a flexible wall, through which page said tube is adapted to pass with said wall in engagement therewith, said housing comprising a third chamber with said flexible wall defining a surface thereof, said second chamber terminating in an outlet to which an end of said tube is adapted to be secured, thereby in effect to close the bottom of said second chamber, the method of tube eversion comprising (1) feeding the tube to be everted through said first chamber, passage and said second chamber and securing the leading edge of said tube to said outlet, (2) supplying fluid at in elevated pressure to said third chamber so as to press said flexible wall against said tube, thereby to substantially separate said first and second chambers, and (3) while retaining the fluid in said third chamber at an elevated pressure, supplying fluid to said second chamber at a sufficiently elevated pressure to act on said tube to evert it out from said apparatus while causing said tube to move axially along and past said flexible wall.

2. In the method of claim 1, supplying to said chamber fluid at a sufficiently elevated pressure to retain said fluid in said second chamber substantially at its said elevated pressure.

3. In the method of claim 1, supplying fluid to said first chamber until the level of fluid therein stands at a predetermined position sufficient to retain said fluid pressure in said second chamber substantially at its said elevated pressure, and maintaining said fluid level in said first chamber substantially at said predetermined position while said tube passes through said first and second chambers and is everted out from said apparatus.

4. In the method of any of claims 1-3, attaching one end of a hose to the trailing end of said tube, continuing the eversion of said tube from said apparatus while substantially retaining said elevated pressure in said second chamber until said tube is fully everted, and then supplying fluid to said hose so that said fluid can pass through said hose and then act upon the interior of said everted tube.

5. The method of claim 4, in which means are exposed in said first chamber for providing a flow of fluid thereto, said means terminating in an end, the step of providing fluid to said hose comprising attaching the other end of said hose to said end of said fluid-providing means exposed in said first chamber..Iadd.

6. A method of everting a tube for inserting into an existing conduit to be lined, comprising:

feeding the tube to be everted into an eversion apparatus including a housing having first and second open ends and a passage therethrough defined at least in part by a flexible wall, through which passage the tube to be everted can pass;

said housing including a sphincter valve with a chamber defined by said flexible wall at said first end of said housing, and an eversion pressure chamber having an inlet and terminating in an outlet defined by said second end of said housing, to which an end of said tube is adapted to be secured, thereby closing said outlet of said eversion pressure chamber and said sphincter valve adapted to seal the inlet of said eversion pressure chamber;

securing the leading end of said tube to the outlet of the eversion pressure chamber,

supplying fluid under pressure to the chamber formed by the flexible wall of the sphincter valve to cause the flexible wall to engage said tube, sliding said tube through the sphincter valve to allow said tube to move through said eversion apparatus,

retaining the fluid at an elevated pressure so that said flexible wall is sealingly pressed against the tube sliding through the sphincter valve; and

providing eversion fluid under pressure to said eversion pressure chamber to cause the tube to evert from said apparatus while causing said tube to continue to move through said eversion apparatus..Iaddend..Iadd.

7. The method of everting a tube of claim 6, wherein the fluid under pressure supplied to the chamber formed by the flexible wall is air..Iaddend..Iadd.8. The method of everting a tube of claim 6, wherein the fluid under pressure provided to the eversion pressure chamber is water..Iaddend..Iadd.9. The method of everting a tube of claim 7, wherein the fluid under pressure provided to the eversion pressure chamber is water..Iaddend..Iadd.10. The method of everting a tube of claim 6, wherein the pressure of the fluid supplied to the chamber formed by the flexible wall is higher than the pressure of the fluid provided to the eversion pressure chamber..Iaddend..Iadd.11. The method of everting a tube of claim 6, wherein the pressure in the chamber formed by the flexible wall is maintained independent of the pressure in the eversion pressure chamber..Iaddend.