Frame for trenchless pipe replacement system and method

#Trenchless pipe replacement is useful for replacement of pipes without the need to excavate the length of the pipe to be replaced. An example of trenchless pipe replacement includes pulling a cutting blade with an expander through the pipe to be replaced, and attaching a new pipe behind the cutting blade. The pipe to be replaced is split, and pushed into the surrounding soil, and the new pipe, of equal or larger diameter, is pulled into the new space within the split pipe. Splitter are commonly used for small diameter pipes, and for pipes of a material that lends itself to splitting. Another example of trenchless pipe replacement includes pipe bursting.

#Gas lines are one example of pipes where splitting is useful in pipe replacement. An example includes high density polyethylene (HDPE) gas pipe. Large quantities of 2 inch diameter HDPE gas pipes are currently in need of replacement. 300 miles of gas pipe in a single city in need of replacement is not uncommon. Given the desirability of minimizing trenches, it is also desirable to minimize the size of entry and exit pits for operating trenchless equipment. Cutting pipes in small entry and exit pits can be a challenge due to the small amount of available space to operate cutting tooling.

#FIG. 1 shows an isometric view of a pipe replacement system according to an embodiment of the invention.

#FIG. 2 shows a cutaway side view of the pipe replacement system from FIG. 1, according to an embodiment of the invention.

#FIG. 3 shows a close up view of a portion of a pipe replacement system according to an embodiment of the invention.

#In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and mechanical, structural, or logical changes, etc. may be made without departing from the scope of the present invention. The term “cable” in the following detailed description is used in a broad sense, and is intended to include any number of flexible lines such as wire rope, and other flexible materials that are sufficiently strong for pipe bursting operations.

#FIG. 1 shows an example of a pipe replacement system 100. A cable pulling system 110 is shown coupled to a top portion of a cable guide frame 120. A cable 102 is shown in place as in a pipe replacement operation. A continuous tension cable pulling system 110 is shown. In FIG. 1, a winch configuration provides a continuous tension on the cable 102. In other configurations, a cyclic cable pulling system 110 may be used. In the example shown, the cable pulling system 110 includes a winch with dual capstans 112, that is separately removable from the cable guide frame 120, and can be used with different configurations of cable guide frames 120 as shown in examples below.

#In selected examples, a manhole adapter 124 is included to locate and support the pipe replacement system 100 adjacent to the pipe to be replaced. Although a manhole adapted configuration of a pipe replacement system 100 is illustrated, the invention is not so limited. Other configurations may be adapted for keyhole pipe replacements, or for open exit pit pipe replacements.