Resin impregnation tower for cured in place liner

Abstract

A resin impregnation tower for continuously impregnating the resin impregnable layer of a tubular cured in place liner is provided. The tower is of a height to provide sufficient resin pressure head to impregnate the resin impregnable layer fully. A cured in place liner having at least one layer of resin impregnable material is fed into the top of the tower, drawn down about a roller at the bottom, removed from the top of the tower and then wrapped with an outer impermeable coating. The impregnated liner is suitable for pull-in-and-inflate method of installation or may be inverted. For liners formed with an inner impermeable layer, the liner is suitable for curing with steam.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of co-pending application Ser. No. 10 / 704,461 filed on Nov. 7, 2003.BACKGROUND OF THE INVENTION [0002] This invention relates to cured in place liners for trenchless rehabilitation of existing conduits and pipelines, and more particularly to an impregnation tower for the continuous impregnation of cured in place liners that may have an inner impermeable layer to be wrapped with an outer impermeable layer for the trenchless rehabilitation of existing conduits by pulling in and inflating. [0003] It is generally well known that existing conduits and pipelines, particularly underground pipes, such as sanitary sewer pipes, storm sewer pipes, water lines and gas lines that are employed for conducting fluids frequently require repair due to fluid leakage. The leakage may be inward from the environment into the interior or conducting portion of the pipelines. Alternatively, the leakage may be outward from the co...

AI Technical Summary

Benefits of technology

[0020] Yet another object of the invention is to provide an improved method of manufacture of a resin impregnated cured in place liner having an outer impermeable coating or wrapping in continuous lengths without use of vacuum.

Problems solved by technology

It is generally well known that existing conduits and pipelines, particularly underground pipes, such as sanitary sewer pipes, storm sewer pipes, water lines and gas lines that are employed for conducting fluids frequently require repair due to fluid leakage.

The leakage in the existing conduit may be due to improper installation of the original pipeline, or deterioration of the pipe itself due to normal aging, or the effects of conveying corrosive or abrasive material.

Cracks at, or near pipe joints may be due to environment conditions such as earthquakes, or the movement of large vehicles on the overhead surface, or similar natural or man-made vibrations, or other such causes.

Regardless of the cause, such leakages are undesirable and may result in waste of the fluid being conveyed within the pipeline, or result in damage to the surrounding environment and possible creation of dangerous public health hazards.

If the leakage continues it can lead to structural failure of the existing conduit due to loss of soil and side support of the conduit.

Because of ever increasing labor and machinery costs, it is increasingly more difficult and less economical to repair underground pipes or portions that may be leaking by digging up the existing pipe and replacing the pipe with a new one.

However, the process still requires eversion of a bladder into the pulled-in impregnated liner.

This process avoids the eversion below grade, but is severely limited into the length of lining that can be laid out above ground prior to pulling-in.

The disadvantages here involves the difficulty faced when trying to impregnate the resin impregnable material disposed between the inner and outer impermeable coatings.

Notwithstanding the modifications to both the eversion and pull-in and inflate trenchless rehabilitation methods, both processes are labor intensive, require an eversion step and suffer from the increased costs associated with this.

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