Trenchless Pipe Installation

Advantages of using HDD installation:  

• Smaller bore hole
• Safe pulling allowance
• Lower material weight
• Standard fittings
• Immediate reconnections

 HDD installation process:

1. Guided pilot hole is drilled along a bore path under the obstruction, or per the required alignment
2. Drilling fluids are used in the bore hole to stabilize and lubricate the operation
3. Various reamers may be used to enlarge the pilot hole
4. Multiple passes may be required to accommodate the required pipe OD
5. Drilled bore hole is typically enlarged to 1.5 x OD of new pipe
6. Joined pipe is pulled back after bore hole preparation is completed
7. Drilled holes are stable for a limited time. Entire fused lengths are typically pulled in at one time, with no interruptions

Click HERE for more information about the HDD installation process for Fusible PVC^® pipe.

Advantages of pipe bursting: 

• Maximum flow area
• Superior material properties
• Standard fittings
• Safe pulling allowance

Pipe bursting installation process: 

1. Static hydraulic method is used to install Fusible PVC^® pipe by pipe bursting methods
2. A burst head is pulled through existing pipe - fracturing or cutting the pipe as it is advanced
3. Fractured or split existing pipe is pushed into the surrounding soil by an expansion head
4. New Fusible PVC^® pipe is attached to the pipe bursting assembly and pulled in immediately behind the expansion head
5. Typically done in 300 - 500-foot increments (~1 hour pull-back time)
6. Utilizes existing alignment - avoids concerns about overcrowded utility corridors and costly inadvertent construction hits that are common with open trench construction
7. Results in the same or larger ID (upsizing) as the existing pipe

Click HERE for more information about the pipe bursting installation process for Fusible PVC^® pipe. 

Advantages of jack-and-bore: 

• Integral restrained joint provides smaller OD for given ID and pressure class, facilitating the smallest possible casing diameter and eliminating restraint fitting cost
• Lower casing material cost
• Lower casing installation costs due to smaller bore hole size
• No casing spacers required
• Low-profile restrained joint can rest directly on the bottom of a casing pipe, which eliminates the requirement for casing spacers
• Non-metallic carrier pipe eliminates requirement to insulate the carrier pipe from the casing

Advantages of sliplining:  

• Use standard fittings to reconnect to PVC and ductile iron pipe
• Eliminates electro-fused couplings or in-pit fusion of adaptors
• Simplifies maintenance and fittings inventory
• Significantly greater flow capacity
• Larger ID for equal OD and pressure versus HDPE (≥ 25%)
• PVC C-factor of 150 often offsets ID reduction
• Fully stand-alone structural solution
• No reliance upon host pipe for pressure rating
• Enables downsizing of casings due to smaller OD
• Smaller OD for similar ID and pressure class versus HDPE
• Greater pull strength and less pipe weight
• More than 2X the tensile strength and pull force of HDPE
• Enables longer pulls requiring fewer installation pits
• No relaxation period required for reconnection

Sliplining installation process: 

1. The clearance needed between the host pipe inner diameter and the new pipe outer diameter will depend on the condition and alignment of the host pipe, but typically should not be less than 2 inches.
2. The host pipe should be surveyed prior to design and any sliplining operation, including video using a CCTV camera that is pulled through the entire pipeline, as-recorded information regarding the pipeline, and actual field surveys.
3. The pipe can be pushed or pulled into the host pipe, depending on layout room and alignment, using common construction equipment of the industry.
4. Once the new pipe is installed within the host pipe, the area between the two conduits should be treated to eliminate the annular void space. This may include grouting, filling with blown sand or flyash or some other media to provide some restraint, side support for the new pipe and increase ring stiffness.
5. Utlilizes existing alignment - avoids concerns about overcrowded utility corridors and costly inadvertent construction hits that are common with open trench construction.
6. Sliplining, because you are inserting a smaller pipe into a larger one, generally reduces the flow area of the host pipe, depending on the original condition of the host pipe. If more flow is required than can be achieved with sliplining, another installation methodology, such as pipe bursting, can be evaluated.

Click HERE for more information about the pipe bursting installation process for Fusible PVC® pipe.  

Advantages of the Tite Liner^® system:

• Long pull lengths
• Low cost and time
• No maintenance
• Temperature limitation
• Chemical resistance
• No pressure limitation
• Leak-free connections
• Increased operating efficiencies

Tite Liner® system installation process: 

1. Before installation can begin, a new or existing host pipeline is sectioned to allow for the insertion of Tite Liner® pipe. Once on site, short individual thermoplastic pipe lengths are joined together by thermal fusion to form long, continuous lengths of liner pipe. A blow-down pig and sizing plate are then attached to a steel cable and sent through a section of the host pipeline. Once the steel cable reaches the other end of the section, it is attached to a pullhead on a corresponding length of liner pipe.
2. A wireline unit pulls the liner pipe through United’s roller reduction box positioned at the insertion end of the host pipe. The liner pipe is compressed radially as it passes through the roller reduction box (Fig. 2). This temporary reduction provides sufficient clearance between the OD of the liner pipe and the ID of the host pipe to allow for insertion. While the liner is pulled into the host pipeline, the liner remains under axial tension, and the reduced OD is maintained.
3. When the tension is released, the liner pipe expands, creating a tight fit against the inner wall of the steel pipe (Fig. 4). Following relaxation of the liner pipe, custom manufactured polyethylene flange-fittings are attached at each end of the lined section. A steel spacer ring is placed around the raised face of the steel flange and the polyethylene flange-fitting to help ensure a leak-free connection. The two steel flanges are positioned together and the line is tested and bolted-up before placing in service.

Click HERE for more information about the Tite Liner^® system.