In the recent past, workers replacing buried pipes such as those used for water, sewer, or natural gas found themselves having to dig a traditional construction trench. However, there is a way to complete the replacement of lines without the expense and environmental damage associated with traditional construction methods through a procedure known as pipe bursting.
How Pipe Bursting Works
In traditional pipe replacement, crews dig large trenches to access the lines they need to replace. They then excise the old plumbing and replace it with similar or larger sized pieces. Once completed, they fill in the trenches. Typical replacements can take days, weeks, or even months depending on the size of the job.
Pipe bursting eliminates the need for digging large trenches. Instead, workers dig a series of launching and receiving pits through which the replacement pipe is installed. As the new pipe is laid in place, a tube-bursting tool destroys the old lines. The device is retrieved from the receiving pit and used again on the next section of piping.
There are four different means of pipe bursting including lateral, pneumatic, hydraulic, and static pipe bursting. Each has benefits and specialized uses.
- Lateral bursting involves the use of a steel cone. The cone is pushed through the existing plumbing to break it apart. Relatively small diameter pipes, with less than four inches in diameter, use this method of lateral bursting. It also the best choice for pipes with multiple bends. In some cases, a rotary device is used instead of the cone.
- Pneumatic pipe bursting involves workers using a pneumatic head with a size expander. Much like a jackhammer, the expander on the head breaks the old pipe. Crews install the new tubing in the old tube’s space. Typically, tubes with diameters between four and fifty-four inches use pneumatic bursting. Common types of pipe replaced in this manner include pressure and gravity pipes.
- Hydraulic Bursting is common when dealing with steel and iron pipes such as a manhole (read the article "Dig We Must: Small City Manhole Rehabilitation" for more information). The bursting head uses hydraulic cylinders to expand and crack the pipe. After expanding, the head contracts which allows placement of the new tube.
- Static bursting is the standard method to replace water and gas lines and other four to forty-eight-inch iron or steel pipelines (read "Why the Oil and Gas Pipeline Industries are Eyeing HDD"). The static method uses a high-tension drum or hydraulic jack winch. It is the simplest way to replace these lines.
Why Use Pipe Bursting
Pipe bursting is an efficient and cost effective way to access old or deteriorated pipes instead of spending hours, or even days, digging conventional trenches. Damaged pipes have to be removed and disposed of properly which entails replacement costs, this means damaging lawns and gardens at great expense for homeowners, and even more for city repairs as the costs incurred related to infrastructure includes having to repair roadways or sidewalks in addition to any soil disruption.
In addition to overall cost effectiveness, pipe bursting takes less time to complete. Home projects usually last a day from start to finish. Larger, commercial projects may take longer.
Why Is Pipe Bursting Growing in Popularity
Pipe bursting technology is gaining popularity in part due to the fact that it is safer than traditional methods. Natural elements such as asbestos and mold are often found in the ground. With less dirt disturbed, workers are exposed to less of these harmful agents.
For businesses who specialize in underground pipe repair, productivity is a factor. With less time digging and cleaning up, productivity is higher. Job completion is more accurate and effective than traditional trenching methods. Companies can lay an average of 200 meters of pipe per day using pipe bursting methods.
Benefits of Pipe Bursting over Other Methods
When discussing benefits of pipe bursting, the first thought is cost. It does cost less than traditional trench work. It also takes less time with home based projects often completed within a day.
Pipe bursting is less labor intensive. While there is machinery involved to dig the launch and receiving trenches, it is significantly less than what is used to move large amounts of soil.
With trenching, an entire lawn has to be torn up. Large trenches can cause geological settling which can damage foundations. With trenchless pipe bursting, only a small area is disturbed, leading to less damage due to soil settlement.
Pipe bursting allows for a greater flow capacity. Even when installing the same sized pipe, consumers see a better flow through the new plumbing. With bursting techniques, it is easy for contractors to install larger diameter pipes in the same area as well.
The use of pipe bursting technology allows workers to complete jobs more efficiently and accurately than traditional pipe repair methods. With less exposure to unhealthy elements, workers are safer and more productive.