Pipe Bursting Machines
Pipe Bursting Machines
Pipe bursting is a trenchless technology method used to replace established pipelines in the same alignment without physically removing the existing pipeline. Bursting by using the exiting established alignment to replace a pipe avoids the need to secure additional right-of-way to install the replacement pipe. Bursting can be used to upsize the pipeline increasing its flow capacity.
Pipe bursting was initially developed in the 1980s to replace small diameter cast iron gas distribution lines, but has since grown in acceptance as an effective method for replacing pipelines diverse in size, material type, and function including water, sewer, or gas pipelines.
Pipe bursting is used to replace brittle pipes such as clay, concrete and cast iron through the application of a static or pneumatic bursting head to fragment the established pipe. Simultaneously, a new product pipe attached to the back of the bursting head is installed in the same alignment as the original pipe.
The pipe bursting process consists of advancing a conical-shaped bursting head that has a diameter 50 to 100 mm larger than the new replacement pipe, through the existing pipe. The radial expansion caused by the geometry of the bursting head surmounts the host pipe’s tensile and shear strength capacities, resulting in the fragmentation or splitting of the pipe. As the bursting head is pulled through the host pipe, the fragments are pushed into the resulting annulus, creating a cavity for the product pipe. The product pipe immediately follows the bursting head as it is simultaneously pulled or pushed into the newly formed cavity.
The suitability of employing pipe bursting depends on numerous factors including burst length, host pipe material, upsize diameter, and geological conditions. For sewer replacement, burst lengths are generally 91 to 137 m (300 to 450 ft), which is the typical distance between manhole locations in a built up municipal setting. Potable water replacement projects typically involve installing new lines of 200 mm, 250 mm, or 300 mm between valve locations. The majority of pipe bursting is employed for upsizing from 150 to 200 mm, 200 mm to 250 mm or 250 to 300 mm.