By Dan Deitz

For centuries, the Central Asian nation of Uzbekistan was a commercial center known for the "silk road," an ancient trade route on which caravans carried silk, bronze, perfume, and porcelain between China and Istanbul. Today, Uzbekistan is a commercial center once again, having become one of the top 10 producers of crude oil in the world. Pipelines have replaced caravans in carrying Uzbek wealth, but at great ecological risk: During the Soviet and immediate post-Soviet period, the country's environment was damaged by leaking pipelines and an aging petrochemical infrastructure.

The surge in investment in Uzbekistan's oil industry following the breakup of the Soviet Union has presented an opportunity for the country to balance economic development with protecting the environment. Although investment funds are flowing into the country, taking advantage of this opportunity isn't as easy as it might sound. Standards for pipelines and other industrial infrastructure remain a gray area, and in many cases it's impossible to use Western-standard, mass-produced components with Soviet-era equipment.

In such an environment, both entrepreneurial zeal and engineering skills are needed to jump-start the country's economy, protect its environment, and turn a profit. What's also emerging as a critical ingredient to success is engineering software: By enabling users to quickly and easily perform what-if analyses, simulation codes help engineers balance the needs of economic development with environmental concerns while still making money.

A case in point came when the government of Uzbekistan recently hired a large U.S. engineering firm to expand an oil-collection facility. The firm faced a number of unusual and potentially hazardous engineering problems because the size and the pressure of the Soviet-era pipes in the facility were right off the engineering charts—double the size of a typical U.S. plant.

A key problem was finding branch fittings—the tees, elbows, reducers, and pipettes that join pipes at various angles—to meet the requirements of the job. Because of the unusual size and pressure of the pipes, it was impossible to use standard, off-the-shelf fittings. Uzbekistan turned to Houston-based WFI International Inc., a well-known manufacturer of custom pipe-branch fittings.

The Uzbek contract called for branch fittings unlike any WFI had previously made. Because the design was new, the fittings for the Uzbek project had to undergo WFI's rigorous testing program. Key to WFI's testing program is the analysis of designs using FE/Pipe software from Algor Inc. in Pittsburgh. Algor's finite-element-analysis software creates a computer simulation of mechanical tests, saving thousands of dollars and valuable engineering time.

"There's too much at stake not to use the software—for the plant employees, the neighbors, the environment, and the plant's bottom line," said Robert Schrader, president of WFI. "With the software we get analysis questions answered faster, more accurately, and less expensively than is possible with any other option," said Phil Ellenberger, WFI's engineering manager.

"We test the design of every type of fitting we make to ensure it will perform properly in its real-world conditions," Schrader said. FE/Pipe provides quick solutions to piping-design challenges using advanced finite-element technology, coupled with ASME code guidelines.

A complex piping system faces a variety of stresses that can cause a dangerous rupture in the system. Ruptures are most likely to occur at joints where two pipes meet. When WFI designs and manufactures the fittings that form these joints, it must contend with two sources of stress. FE/Pipe's intersection analysis capabilities test for the types of stresses that occur where fittings are attached to the pipes.

Engineers used FE/Pipe finite-element-analysis software to determine where stresses occur in this custom-built pipe-branch fitting.

The pressure of fluid moving through the pipes threatens to burst the pipe at any weak point. When a pipe is fitted into the side of another, the pipe with the hole cut into its side is weakened. The fitting which joins these two pipes must be designed to reinforce the holed pipe. The engineers performed stress analyses on holed pipes using FE/Pipe to ensure that they don't burst under pressure.

Branch fittings that join pipes at various angles face additional stresses as changes in temperature and pressure flex the system and the fitting is pushed and pulled in contrary directions. These stresses cause metal fatigue that can break the fitting. In fulfilling the Uzbek contract, WFI engineers used FE/Pipe to determine how pressure and temperature changes would affect these pipe fittings during operation.

Stress from temperature variations is a particular problem in the high desert of Uzbekistan. In summer, temperatures of 113°F are common, while in winter, temperatures can drop to —35°F. In a given day, temperatures may vary as much as 50°F. These wide fluctuations in temperature place dangerous stresses on the fittings. Engineers used Algor's heat-transfer-analysis software to determine whether the temperature changes would cause the pipes to weaken to unsafe levels.

The traditional way to find out how much stress a fitting can withstand is to push it until it breaks. For the large fittings WFI was designing for the Uzbek project, the cost of destructive testing could be as much as $50,000 per test, and would require elaborate preparations and lots of time.

"There wasn't the budget or time to test a scale model or conduct a destructive physical test, which are the conventional ways to test an unproven design," Ellenberger said. "Even if there had been, we wouldn't have known if we had designed the model right for its unique real-world conditions.

"The fittings WFI makes are even more complicated to analyze because they're customized," he added. "There's no prior 'road map' for the fittings we design. FE/Pipe enabled us to tackle this enormous design challenge head-on," explained Schrader.

WFI used FE/Pipe to enhance its extensive mechanical testing program. "Without the software, the complexity of the analysis could have made the project insurmountable," Ellenberger said. FE/Pipe simplifies the task of modeling and analyzing critical piping system components. Finite-element technology and built-in ASME code checks are combined with automatic modeling. With FE/Pipe, the engineer is able to model a component in piping-system terms such as diameter, thickness, and pressure.

Armed with this information, WFI engineers quickly determined such critical design information. Built-in code-checking and finite-element capabilities enable them to ensure that components will perform as needed to keep Uzbek oil flowing smoothly, cleanly, and safely.


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