The annual cost of metallic corrosion worldwide is staggering. Inherently corrosion-resistant, composites are ideally suited to replace metals.
One of the most pressing needs in terms of corrosion mitigation is rehabilitation of aging underground pipe, especially in pipelines that carry potable (drinkable) water and wastewater. A newer twist on pipe relining — already a much less-expensive option than excavating and replacing buried pipe — is exemplified by BLUE-TEK technology, from Reline America Inc. (Saltville, Va.). The fiberglass fabric liners Reline uses are impregnated with an ultraviolet (UV)-curable Vipel unsaturated polyester from AOC Resins (Collierville, Tenn.), in which a photo-initiator additive drives the cure. UV-curing enables quicker installations that require no heating equipment, and liners can be shipped without refrigeration, all of which reduces cost.
Source: Reline America
When Hurricane Sandy devastated the northeastern US seaboard, the Wildlife Conservation Society’s New York Aquarium’s damaged Aqua Theater bleacher seats and wooden walkway were redesigned and rebuilt with pultruded composites to stand up to corrosion, because the exhibit’s centerpiece is a pair of saltwater pools and it is located on Coney Island’s Atlantic shore in Brooklyn, N.Y. (Read more at "Sea lion exhibit: Pultrusions renew seaside aquatic show venue," under "Editor's Picks," at top right.)
Strongwell Corp. (Bristol, Va.) supplied EXTREN pultruded fiberglass/polyester structural support profiles, including angles, plates and I-beams, to support it’s trademarked DURADEK pultruded I-6000 fiberglass/vinyl ester grating. These composite components were used to create the audience seating and standing areas, as well as an irregular, decorative pool edge (shown here from the underside) onto which 500-lb sea lions can pull themselves from the water.
Car and truck manufacturers are finding composites useful in fighting corrosion in powertrain components exposed to weather, road salt and chemicals that can damage metals. A thermoplastic composite, for example, replaced cast aluminum in the transaxle inspection cover assembly on the CRD 150/1 drive axle produced by American Axle Manufacturing Inc. (Detroit, Mich.) for tandem-axle line-haul, refuse, dump, and mixer trucks like this one, built by Mack Trucks Inc. (Greensboro, N.C.).
Source: SPE Automotive Div.
The new cover’s tough thermoplastic composite reportedly eliminates the corrosion — lengthening the part's service intervals — and also reduces part weight and cost.The two-piece assembly, molded by Sturgis Molded Products (Sturgis, Mich.) features a 55 percent short-glass-and-mineral reinforced Reny PA-MXD6 aromatic polyamide.
Source | SPE Automotive Div.
A detailed inspection of this 1.5m-diameter glass/polyester pipeline filament wound by what is now Flowtite Technology AS (Sandefjord, Norway) and installed at the Vinkelfallet power plant, north of Lillehammer, Norway, showed that composites clearly deliver on their promise of corrosion resistance (see next photo).
Although a thin layer of black soil covered the interior surface of the 30-year-old Vinkelfallet pipe when inspectors entered the pipeline, it was easily washed away with water to reveal a smooth and polished fiber-reinforced plastic inner surface. A visual inspection showed no signs of wear or damage. (Learn more by clicking on "Inspection: 30-year-old fiberglass pipeline stands test of time," under "Editor's Picks," at top right.)
FRP has infiltrated recent hydrometallurgy installations in North America. In the past five years, three large hydrometallurgy plants have been built in North America. One example is mineral processor Vale’s (Newfoundland, Canada) Long Harbour complex (pictured here), which is processing nickel, cobalt and copper ores from the Voisey’s Bay mine. Hundreds of storage tanks, extraction vessels and electrowinning cells, and miles of acid- and abrasion-resistant piping have been fabricated, primarily from epoxy vinyl ester resin and corrosion-resistant glass fiber, such as E-CR glass. (Learn more by clicking "Fossil & Mineral Resources: composites expand," under "Editor's Picks," at top right.)
Source | Vale
Composites have established a solid market position in corrosive applications but, occasionally even chemical-resistant fiberglass needs help, for very severe service. That’s where dual-laminate vessels come in: a tough thermoplastic liner inside a fiberglass-reinforced polymer (FRP) structure provides double protection in critical applications, especially where project size and scale make titanium, stainless steel or high-nickel alloy solutions cost-prohibitive. This 33m tall, 5.5m diameter dual-laminate scrubber vessel was built by RL Industries (Fairfield, OH, US). for a chemical plant application in the Middle East. Learn more by clicking on "Dual-laminates: Scaling up for scrubbers," under "Editor's Picks," at top right.
Source: RL Industries
The annual cost of metallic corrosion worldwide is staggering. Considering the cost of maintenance, prevention, replacement of parts and interruption of services due to maintenance, the World Corrosion Organization (New York, NY, US) says that the annual cost of corrosion worldwide is US$2.2 trillion, more than 3% of the world’s gross domestic product (GDP). The US Department of Defense has estimated the annual cost of corrosion in its military applications alone at more than US$10 billion per year.
Inherently corrosion-resistant, composites are ideally suited to replace metal structures, including tanks, piping, cooling towers, railcars for chemical transport and much more, in this huge sector (see, for example, the photos and captions at left).
The most pressing need is still in the area of underground pipe. It’s been 43 years since Insituform (St. Louis, Mo.) founder Eric Wood invented cured-in-place pipe (CIPP). Since then, CIPP has continued to gain favor as municipalities recognize the huge benefits of an underground pipe rehabilitation technology that enables repair of deteriorating water/wastewater pipelines without expensive excavation.
A seminal report, “Buried No Longer: Confronting America’s Water Infrastructure Challenge,” from the American Water Works Assn. (AWWA, Denver, Colo.) framed the challenge: “Much of our drinking water infrastructure, the more than ... 1,609,344 km of pipes beneath our streets, is nearing the end of its useful life and approaching the age at which it needs to be replaced…. Restoring existing water systems … and expanding them to serve a growing population will cost at least $1 trillion over the next 25 years, if we are to maintain current levels of water service.” At that time, the U.S. Environmental Protection Agency (EPA, Washington, DC, US) counted 240,000 water main breaks per year and expected that number to increase. Yet in 2013, nearly 43% of cities said their 2013 sewer/water/storm water budgets wouldn’t grow, but almost 40% expected increases ranging from 3.0-5.5%. Potable water pipe rehab, then, would climb from US$1.65 billion in 2012 to US$1.7 billion in 2013. Storm water system renovation would be up from US$780 million to US$850 million. And wastewater systems would see US$3.8 billion, up from 2012’s US$3.58 billion. However, city officials projected the actual need for repair and expansion at US$85 billion for water, US$9.6 billion for storm water, and an enormous US$260 billion for wastewater. The 17th Annual Municipal Survey, conducted by Underground Construction magazine (Oildom Publishing Co., Houston, TX, US), reported in October 2014 that, despite strong, continuing funding concerns by cities, municipalities for the first time in several years were expecting a substantial increase (7.7%) in new construction spending for 2014. The rehabilitation market, which maintained at least some growth throughout the recession, should reach almost US$7.1 billion, an increase of 8.4%. Cities short on money for major projects have found that increasing rehabilitation budgets to address specific and concentrated problems was still cheaper than funding major replacement projects.