20 August 2010
20 August 2010
RL Industries has overcome a number of logistical obstacles to successfully fabricate composite storage tanks for a chemical plant in Saudi Arabia.
The job required three large composite tanks to store a 32% solution of hydrogen chloride or a 20% solution of sodium hydroxide. Based on previous experience, the U.S.-based engineer commissioned to design the tanks recommended RL Industries to give the customer the highest level of quality and structural integrity.
Compared to on-site fabrication, RL Industries’ dedicated manufacturing facilities eliminated the potential for ambient contamination and provided better control of process parameters. In addition, the company’s manufacturing is certified to demanding American Society of Mechanical Engineers standards for corrosion-resistant structures.
Vipel Technology & AOC Service
To resist the corrosive nature of the stored chemicals, the resin chosen for the tanks was Vipel F010 bisphenol A, epoxy vinyl ester from AOC.
RL Industries started by filament winding cylindrical sections of Vipel resin-impregnated fiberglass roving. Winding was accomplished over a high performance corrosion barrier, formed with chopped strand mat and two layers of carbon veil in the Vipel resin matrix. Nozzles and attachment features for ladders and rails were integrated into the wound sections.
To moold top and bottom end closures, the Vipel resin was vacuum-infused through fiberglass reinforcements and structural sandwich core. For enhanced load-bearing, RL Industries designed the bottom end closure with an integral, high-strength knuckle radius. The top and bottom end closures were integrated into the cylindrical shell during the shop winding process.
RL Industries Engineering Manager Brian Linnemann explained why Vipel resin technology was specified for all the work. “We turned to AOC because of our favourable history with them on other projects,” he said. “They provide a very good corrosion resin recommendation with excellent documentation of process constituents and chemical service details. A Vipel resin is proven technology that is optimized for the application.”
Assembled for shipping
After the tank sections were manufactured, they were assembled at a site 20 miles (32 kilometers) away. Special permits were obtained to ship the tank sections over the road to the assembly site.
At the assembly site, the cylindrical sections were sequentially assembled and end-result for each tank was a high-strength, monolithic structure ready to go to work when installed.
RL Industries made three 20-foot (6.1-meter) diameter chemical storage tanks for the project. One tank was 47.7 feet (14.5 meters) high; the other two were 41.3 feet (12.6 meters) high.
The contract also called for two 7-foot diameter by 16-foot high (2.1 meters by 4.9 meters), shop-fabricated tanks for holding non-potable water for emergency safety showers. To keep ambient Saudi temperatures from making the water too hot, these tanks have 2 inches (5 centimeters) of sprayed urethane foam insulation encapsulated within the laminate.
After all tanks successfully passed hydro-testing protocols, they were loaded on a barge for transport down the Ohio and Mississippi Rivers to a Gulf of Mexico port. The equipment was then transferred to an ocean-going vessel for shipment to Saudi Arabia.