Optimizing composite technology for pipe repair solutions

For almost 35 years, InduMar Products Inc. has supplied a wide range of industries with emergency repair products for sealing pipe leaks. The most common approach has entailed the application of a composite wrap over leak sites to provide an external barrier and contain the leak without the need for special tools or lengthy interruptions of service. The use of a water-activated urethane in combination with a fiberglass tape (Stop It^® Pipe Repair System) allows for easy application of the composite wrap under a wide variety of field conditions, including underwater. The approach ha s even demonstrated the ability to stop and seal active leaks.

More recently, InduMar has refined its approach to composite technologies to provide more narrowly focused repair solutions addressing a broader range of industries and applications. These include repair needs related to mechanical reinforcement of piping, rehabilitation of surfaces damaged by external wear, sealing production systems containing aggressive chemicals, and protection of components suffering from environmental corrosion. As the specifics of the repair needs change, so must the properties of the composite repair product. Because composites consist of more than one material, the design and optimization of a repair composite requires an understanding of the fundamental properties of each material, as well as how material properties combine and interact to define product performance.

The first, most important step in the design or selection of a composite repair product is identifying the critical requirements. For example, leak-sealing applications require the use of a nonporous and highly adherent polymer matrix. While many composite wraps appear to provide an external barrier, closer inspection reveals microscopic pores can provide pathways for the escape of pressurized pipe contents, while poor bonding allows leaks to persist between the wrap and repair surface. Alternatively, repairs aimed at providing mechanical reinforcement of pipes suffering a reduction in wall thickness rely on the tensile strength and modulus of the repair composite's continuous fiber reinforcements. Repair composites intended to resist external wear or abrasion must possess inherent toughness and strong interfacial bonding.

Beyond the critical needs of the repair, additional requirements are placed on composite repair products. These can relate to details of their application, the interaction and stability of the composite in the environment, the nature of their packaging and delivery to the repair site, and the cost of the composite relative to the cost of asset replacement. In the field of composite design, it is well understood that as the list of requirements grows, so does the difficulty of identifying a product that fulfills them.

Stop It BoreShield^TM ARO II, recently introduced by InduMar to address the abrasion and wear resistance needs of new pipelines and horizontal directional drilling (HDD) boring, provides an excellent example of how the optimization of composite properties can address the stringent needs of a specific repair scenario. The construction of new pipelines involves extensive welding of pipe joints in the field. The weld seams, or nearby pipe sections, have been found to be closely correlated with installation and long-term performance failures.

BoreShield ARO II, a urethane fiberglass composite, is designed specifically to protect the weld seams from external wear and impact encountered when a pipeline is buried and the surface abrasion experienced when piping is pulled in HDD applications. The composite's custom, heavy-duty fiberglass reinforcement is intentionally constructed to allow for easy spiraling across the weld seam region, while the water-activated urethane resin is tailored to an optimal cure time and synthetically toughened to provide high-quality, high-performance installation. Packaged as a pre-impregnated composite, BoreShield ARO II is securely and conveniently delivered to the installation site. Together, these characteristics demonstrate the repair capabilities that can be achieved by optimizing particular material properties of composite technology.

For more information, visit www.InduMar.com or call (713) 977-4100.