Trenchless PE Pipe Installation Method - Advantages And Disadvantages

Posted on: May 31, 2021 by Madison Pipe Industry, 4 min read

What’s the installation method of drag PE pipe? Madison pipe introduces the trenchless pipe installation method to you, and respectively discusses the method’s advantages and disadvantages.

The benefits associated with trenchless pipe installation far outweigh the disadvantages. However, the most attractive factor is that it does not need to interrupt traffic, block the whole section or excavate the whole section to complete the work.

Trenchless technology provides a variety of ways to install different pipe sizes and types, depending on location, soil type and penetration depth. Some trenchless pipe installation methods are horizontal directional drilling (HDD), horizontal auger drilling (HAB), pipe stamping and impact forming. Compared with trenching methods, all these methods have been proved to be time and cost-effective.

However, these methods have some advantages and disadvantages. Knowing which method is helpful to better understand which method is most beneficial to a specific project.

Horizontal Directional Drilling (HDD)

What’s HDD?

HDD is a maneuverable tunneling method, which is a two-stage process, i.e. pilot hole and back reaming. It can be used for small diameter and large diameter pipelines. The best angle of drilling guide hole is 12 °, But it can be adjusted in from 5 ° to 30 ° . This method requires the use of a lubricant called drilling mud(usually bentonite), which circulates in the pilot hole as drilling proceeds. Drilling fluid is conducive to the removal of cuttings and also makes the borehole stable.

Advantages of HDD

There are several advantages to using HDD to install PE pipes. A major advantage of this approach is that it has minimal impact on environmentally sensitive areas such as wetlands, estuaries, rivers and lakes. It is also a fast pipeline installation method, which enables the operator to achieve reliable accuracy even when the intersection is complex. Continuous monitoring and control during operation allows operators to navigate in confined spaces between existing utility lines. Drilling can even be carried out at deeper depths to completely bypass existing utilities, and only one launching shaft is required at the entry point and only one receiving shaft is required at the exit point.

Disadvantages of HDD

The disadvantages of HDD are not many, but they are significant. HDD operation can only be carried out by skilled operators. The cost of equipment and machines requires that the project has enough drilling length to make profits.

Horizontal Auger Drilling(HAB)

What’s HAB?

HAB uses a casing system with a cutting head and a rotary auger, which is inserted into the ground from the launch shaft. As the auger progresses, it transmits torque to the cutting head. The soil chips produced by the cutting head are transported back to the launching pit by the rotary auger. Once the casing and auger are underground, the next set of casing and auger blades are connected to the previous casing and auger, and the process continues to the receiving shaft.

Advantages of HAB

The main advantage of HAB is that casing installation and excavation are carried out simultaneously. It only needs two pits, one for launching and one for digging. The method is applicable to all types of soil except mixed soils containing boulders.

Disadvantages of HAB

The disadvantage of HAB is that the equipment investment is quite large. This method requires different sizes of cutting head and auger to be used for different casing sizes.

Pipe Stamping

What’s Pipe Stamping?

Pipe stamping is carried out by pushing the pipe or casing into the soil with an impact hammer connected to the end of the pipe or casing. The leading edge of the pipe or casing is drilled and the pipe is installed. The spoil enters the pipeline and is removed after installation.

Advantages of Pipe Stamping

The advantage of pipe stamping is that it is very economical and does not require expensive equipment. Pipes can be installed as a whole or in sections and can be installed in almost any type of soil. It is most suitable for medium pipes and shorter lengths.

Disadvantages of Pipe Stamping

The main disadvantage of pipe stamping is that it is unable to control the line and installation level. If hard obstacles (such as hard boulders larger than casing) are encountered, pipe deflection may also be caused. Due to the impact nature of the installation, this method can only be used for steel pipes. Pipe sizes that can be installed using this method are limited to 2 "to 55".

Pipe Stamping

Impact Forming

What’s Impact Forming?

Impact forming is also known as the compression method, which is installed by pushing or pulling the pipe through a hole created by the drill bit. The drill is a bullet shaped streamlined tool that uses a power source for propulsion. The energy is transmitted to the bit by compressed air or hydraulic mechanism, and the bit is pushed to the ground. Once the drilling is complete, the drill bit is removed and the pipe to be installed can be pushed or pulled.

Advantages of Impact Forming

Impact bending is very beneficial for small diameter pipes with short installation length. This method does not need any expensive equipment, and can be used to install any type of utility pipeline, making it an economic method. The molting process helps to compress the soil around the bit, thus stabilizing the borehole.

Disadvantages of Impact Forming

Because the system has no guidance, the influence deformation has some disadvantages, such as the inaccuracy of lines and grades. This may result in damage to existing utility lines that were not detected before the start of the project. Pipe sizes that can be installed are limited to 6 inches or less, although some technologies allow larger sizes and installation lengths are limited to 60 feet, although some technologies allow up to 200 feet.

The various methods available in the trenchless installation kit are sufficient to meet the different types of soil and environmental conditions existing in the installation site. Among all these methods, the most important is to carry out geotechnical investigation on the project site to determine the best method and equipment suitable for the project. The total cost and time saved by using trenchless method is considerable, which is why it has become an indispensable tool in the hands of many contractors, whether it is pipeline installation or repair.

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