When and why is pipe bursting better than CIPP lining?
Pipe bursting was originally designed for replacement of small diameter, cast iron gas distribution lines. The technique has been improved and now accommodates different sizes of pipe to replace water, sewer, or gas lines. Pipe bursting cannot reduce pipe diameter, it specifically addresses expanding pipeline carrying capacity, also known as up-sizing.
Professionals use a variety of guidelines when determining whether pipe bursting is the best choice for residential properties or commercial rehabilitations. These include:
- When repair or renovation is not technically or economically feasible. If the pipe is oval shaped or crushed it has lost its integrity, bursting is the best investment going forward.
- The line’s hydraulic capacity needs expansion, the actual pipe diameter should be larger. Pipe bursting is best for upsizing, smaller pipes are replaced with larger ones, from 100mm to 225mm diameter is common. Pipes of up to 36 inches diameter and greater can be replaced. Gas mains, water mains, and sewers often require this process.
- When pipe replacement is inevitable a short term solution, such as CIPP, should not be approved. Delaying replacement may end up costing more down the line.
- When the static loading capacity of the defective pipe would be negatively affected
- Pipe bursting guarantees longer lasting pipe durability and higher product life span. These pipes are produced with high density polyethylene (HDPE) making them environmentally sustainable, non-toxic, and resistant to corrosion and chemical. They will last up to 50 years.
With launching and receiving pits to provide access on either side of the pipe, bursting is best for shallow lines 6 to 8 feet deep. A new connection to the service owner is another plus. If the pipe has lost its integrity, is oval shaped or crushed bursting is always recommended. Man holes can be used if short pipes are being installed. This method is obviously more suitable for warmer climates. In cold areas the lines are generally buried deeper to avoid the frost line.
Equipment used will include an expander head, pulling rods, a pulling machine, a retaining device, and a hydraulic power pack. Pipe bursting cannot be done under buildings. If there are branches entering the line each area must be exposed. Branches must be disconnected prior to and reconnected after the procedure is complete.
This technology will not remove a belly in the line. This problem occurs when the sewer pipe has lost the positive gravity slope required going to its municipal sewer main of septic tank destination. Additional limitations are:
- Bursting is can only be used to replace circular existing pipes.
- The host pipe may require being out of service during the process.
- Host pipe’s inclination must be usable for the replacements. Heavy encrustation must be cleaned to allow bursting rods to be pushed through or so that the winch rope can be pulled in. Usually, high pressure cleaning to remove debris or clogs are not necessary.Pipe bursting is the overall best choice for the lateral pipelines that branch off to the main or transmission line. There are two approaches. A static methodology is used to replace pressure pipes and employs the bursting rods. Pneumatic pipe bursting is used for gravity sewer and storm pipelines, a winch rope is required.