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, N.Y.) says that the annual cost of corrosion worldwide is $2.2 trillion, more than 3 percent of the world's gross domestic product (GDP). The U.S. Department of Defense has estimated the annual cost of corrosion in its military applications alone at more than $10 billion per year. 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.
Perhaps the most pressing need is in the area of underground pipe. It’s been 42 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. That said, the 16th Annual Underground Construction Municipal Sewer & Water Survey, conducted by Underground Construction (Oildom Publishing Co., Houston, Texas) notes that a huge majority of survey respondents ranked funding (rather, it’s lack) as their biggest challenge in 2013. “After several years of recession and being continuously squeezed by deep budget cuts, municipalities across the country are still waiting for an economic turnaround or a state/federal budgeting miracle that will finally provide some kind of financial relief for cash-strapped city sewer, water and storm water departments,” according to the report. Still, the survey predicted increases in rehabilitation expenditures for 2013. Nearly 43 percent of cities said their 2013 sewer/water/storm water budgets wouldn’t grow, but almost 40 percent expected increases ranging from 3.0 to 5.5 percent. Potable water pipe rehab, then, would climb from 1.65 billion in 2012 to $1.7 billion in 2013. Storm water system renovation would be up from $780 million to $850 million. And wastewater systems would see $3.8 billion, up from 2012’s $3.58 billion. However, city officials projected the actual need for repair and expansion at $85 billion for water, $9.6 billion for storm water, and an enormous $260 billion for wastewater.
Nevertheless, “trenchless technology” has captured nearly half of the market for sewer line rehabilitation and about one-eighth (12.9 percent) of the money spent on repairing potable water pipes, according to Kaleel Rahaim, business manager, remediation polymers, for Interplastic Corp.’s Thermoset Resins Div. (St. Paul, Minn.) who estimated that in North America alone, 106 million lb (48,080,790 kg) of resin is used in CIPP installations annually in a total of 14,318,476 linear ft (4,364,270m) of relined underground pipe.
A seminal report, Buried No Longer: Confronting America’s Water Infrastructure Challenge, from the American Water Works Assn. (AWWA, Denver, Colo.) framed a challenge: “Much of our drinking water infrastructure, the more than 1 million miles/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, D.C.) counted 240,000 water main breaks per year and expected that number to increase.
Another growth market involves underground storage tanks (USTs). The U.S. Environmental Protection Agency (EPA, Washington, D.C.) estimated that petroleum (mostly gasoline) and other hazardous substances were stored in 587,000 (USTs) in the U.S., as of March 2012. The EPA established a UST regulatory program in 1984, to eliminate risk of groundwater contamination from leaks in these tanks. Federal UST regulations now require secondary containment. All new or replacement underground tanks now must have a secondary barrier and an interstitial void between the two walls. Sensors in the void detect leaks and alert tank owners.
Delta Composite Systems LLC (Plymouth, N.H.), for one, has developed its novel GENESIS interior secondary barrier system with ZPlex glass sandwich fabric by 3TEX (Cary, N.C.). Its core of foam strands shrinks when heated, opening a void between the cured interlaced faceskins. This ensures not only containment and interstitial monitoring, but ZPreg also offers a quick and cost-effective way to cover the 700 to 800 ft2 (65 to 74m2) surface area in a typical tank (see “Underground storage tanks: Rehabilitation without excavation,” under “Editor’s Picks” at top right). Delta maintains that it costs $150,000 to $200,000 excavate singe-wall tanks and install double-walled replacements. The average cost for in situ construction of secondary containment is only $30,000 for a typical 8,000-gal to 10,000-gal (30,283-liter to 37,854-liter) tank.
In 2013, one high-profile U.S. anticorrosion application was at the National September 11 Memorial at the World Trade Center site in New York City. FiberSystems Inc. (FSI, Dayton, Ohio) fabricated all the large-diameter piping used to supply waterfalls that feed the Memorial’s two pools, which have the approximate footprint of the original twin towers. Together they hold about 600,000 gal (2.3 million liters) of water, and the water for each waterfall is pumped and recirculated at a rate of about 30,000 gal/min (113,500 liters/min).
As the water circulates it is purified by both chemical treatment and filtration. FSI fabricated ~4,300 linear ft (~1,311m) of 12-inch/305-mm and 16-inch/406-mm diameter pipe via wet filament winding using a “dual-wound” construction. It has an inner layer (or liner) of roughly 30 percent glass-reinforced vinyl ester and an outer layer of about 60 percent glass-reinforced phenolic. The wall thicknesses range from 0.230 inch to 0.290 inch (5.8 mm to 7.3 mm). The high-performance vinyl ester, supplied by Interplastic Corp. (St. Paul, Minn.), provides good hydrolysis, corrosion resistance and structural support; the outer layer is Cellobond J2027L phenolic resin formulated by by Momentive Specialty Chemicals (Columbus, Ohio) and distributed in North America by Mektech Composites Inc. (Hillsdale, N.J.). The phenolic contributes structural support and, importantly, meets New York City’s stringent flame, smoke and toxicity codes. Inner and outer layers are reinforced with boron-free Advantex E-CR glass from Owens Corning Composites Materials (Dublin, Ohio).