IT3 System Features

Key Features of the IT3 System

The IT3 Multiwall Pipe System is built on a design principle that ensures the plastic carrier pipe is separated from the steel containment pipe, delivering several key benefits and features that make it the ideal solution for challenging pipeline environments.

Three-Phase Design

The IT3 System features three distinct layers: an inner plastic liner, an outer steel or hard material casing, and a cement grout filling the annular space between them, creating a robust multiwall piping solution.

Flange or Flange-Free Installation

The system eliminates the need for numerous flanges, simplifying installation and reducing potential leak points. This is dependent on valves, flow monitors, and other components.

Controlled Stress State

The plastic liner remains within its elastic deformation range, extending its lifespan and preventing stress-related failures common in other piping systems.

Liner Material Flexibility

Any type of plastic pipe can be used as the liner, offering adaptability for different applications and fluid types, from corrosive chemicals to high-temperature streams.

Corrosion Protection

The high pH of the cement grout passivates steel and acts as an inhibitor between the OD of the inner liner and ID of the outer steel casing, providing a secondary corrosion defense system.

High-Performance Under Pressure

The IT3 System can handle pressures from vacuum to 3500 psi, making it suitable for a wide range of industrial applications from low-pressure drainage to high-pressure transport lines.

Specialized Features

Collar Coupling

New IT piping systems incorporate a patented coupling device, the Collar, enabling simultaneous welding of the steel and fiberglass components for a robust joint. This innovative coupling technology ensures:

Leak-free connections between pipe sections
Maintenance of the three-phase integrity throughout the pipeline
Simplified installation and joining process
Enhanced structural integrity at connection points

Epoxy application

Epoxy application complete

Collar inset for joining

Final weld

In-Situ Rejuvenation

This proprietary process revitalizes existing pipelines, restoring them to optimal performance and operating standards through the IT3 multiwall system. The in-situ rejuvenation process offers:

Minimal disruption to surrounding infrastructure
Significant cost savings compared to full replacement
Extended pipeline life by decades
Improved flow characteristics and reduced maintenance
Ability to address localized corrosion issues effectively

Centralization Technology

A critical part of the IT3 process is liner centralization, because the liner must be centralized to maintain effectiveness of the overall IT3 concept.

Without centralizers, a buoyancy effect arising from a plastic tube being immersed in a cement slurry (specific gravity 1.8) tends to float the liner upward just after the liner has been grouted in. In regards to rejuvenation applications, however, most of the localized corrosion occurs at the bottom of the pipeline since aqueous media tends to concentrate in this area and also due to the very mechanism of pit propagation. Hence, it very often becomes an advantage to retain a greater thickness of cement grout on the bottom side of the pipeline.

Centralizer device

Cross-section showing liner placement

Moreover, the cement thickness affects the stress state of the plastic liner very little. Revisiting the example from the technology page, it was found that, with uniform cement thickness of .75", the P.V.C. bears a stress of 160 psi, which is well below its tensile critical stress of 2,600 psi.

Even with varying grout thickness (e.g., 0.3" at the top and 1.2" at the bottom), stress on the plastic liner varies insignificantly. With most standard in-situ rejuvenations, it is preferred to avoid the use of centralizers, though in other intricate situations, centralizing techniques have been and will be used.

Varying grout thickness: .3" at top, 1.2" at bottom

Applications

The main target with the majority of multilayer processes is to combine various properties that are difficult, if not impossible to achieve in a single material. The IT3 System is suitable for a wide range of applications: