Composite Wrapping System is a permanent, cost-effective pipeline repair technology, suitable for non-leaking defects such as pits, dents, gouges, and external corrosion. Composite Wrapping System can be performed on an operating pipeline without taking it out of service. This repair technique is quick and generally less costly than other repair options, and it permanently restores the pressure-containing capability of the pipe when properly installed.
Composite Wrapping System can serve as an alternative to the traditional pipeline repair practices such as pipeline replacement or the installation of full-encirclement steel split sleeves. Compared to these traditional practices, Composite Wrapping System repairs are generally less expensive, time consuming, and labor intensive. In the case of pipeline replacement, Composite Wrapping System has additional advantages of avoiding customer service interruptions and eliminating methane emissions associated with the venting of the damaged pipeline.
Both the pipeline replacement and steel sleeve installation procedures are expensive, time-consuming, and labor intensive. Pipeline replacement requires that the affected portion of the line be shutdown, often resulting in service interruption. The gas in the line is then purged, the affected segment is cutout, and a new segment of pipeline is welded into place. Steel sleeves are typically used to repair leaking or weakened pipe without shutdowns. The damaged pipeline is excavated, the pipe exterior is cleaned, and the stainless steel split sleeve is bolted or welded into place.
Use of composite wrap as an alternative to pipeline replacement can reduce safety risks, decrease pipeline downtime, save gas for sale, and decrease methane emissions to the atmosphere. Composite wrap systems allow pipeline repair without shutting down gas flow, purging the pipeline, or cutting into the pipe. Composite wrap systems operate by transferring the hoop stress from the defect through a high compressive strength filler to a composite sleeve, which is wrapped around and bonded to the pipe. Composite wrap sleeves are considered full-encirclement repairs.
When considering the use of composite wrapping system, important decision factors include the depth and length of wall loss or deformation, yield strength, defect depth, defect axial length, pipeline diameter, wall thickness, and pipeline operating pressure. While detailed field measurements are needed to make a final decision. Composite Wrapping System may be an ideal choice for non-leaking defects when repair is urgently required, must be completed quickly, and no backup gas supply is available.
The cost of Composite Wrapping System can range greatly depending on the length of the defect and the pipeline diameter. The primary costs for installing a composite wrap sleeve are labor costs, equipment and materials, and indirect costs such as permits and inspection services. It is important to note that in some circumstances (i.e., certain long defects), pipeline replacement is the most cost effective repair option, despite the gas losses.