The National Archives Building
Preserving a Nation’s Heritage The lighting in the hushed, marbled Rotunda of the National Archives building in Washington, D.C., mimics the soft glow of candles. Uniformed guards stand silently beside newly designed encasements that safely cradle the original documents that have guaranteed the rights and freedoms of Americans for more than 200 years. | Safe, secure, but accessible—the four pages of the Constitution in new encasements in the Rotunda of the National Archives. | Time and travel have faded these precious documents—some almost beyond readability. Moths have nibbled on the edges of the parchment made from animal skins. The Declaration of Independence, the Constitution, and the Bill of Rights, collectively known as the “Charters of Freedom,” are the main attractions in the newly restored Rotunda of the National Archives building.
The documents rest surprisingly close to visitors, only inches away from children’s fingertips and adult appreciation. Installed in 2001, the encasements are framed in titanium, plated with a thin layer of gold, and are protected by bulletproof glass.
What lies beneath the protective display is what took researchers at the National Institute of Standards and Technology (NIST) and a group of our nation’s leading scientists seven years to design and build.
On the National Archives project, NIST used Swagelok® B series bellows valves, tube butt weld fittings, and VCR® fittings—nothing out of the ordinary—but the application for these products was history in the making.
“We have worked with project teams at NIST for over forty years,” says John Bevacqua, distributor, Washington Valve & Fitting Co. “NIST is the home to researchers and scientists in the purest sense. Our distributorship has been called upon often to provide not only products, but also to provide expertise on instrumentation configurations and project solutions.”
Each of the seven encasements is a self contained, passive system with an interior environment of 67°F (19.4°C), plus or minus two degrees. Argon gas with the addition of 2 percent helium and a relative humidity of 40 percent fills each case for optimum preservation of the parchment and ink.
Although each encasement is designed to allow opening for document examination by conservators, the frame’s surface is machined, diamond turned, nickel plated, and post polished to provide a leak free seal.
In the case of the National Archives, Mark Harris, Washington V&F sales representative, comments, “The service we provide is critical. Researchers and scientists at NIST work all hours of the day and night on some very unique and special projects—we make hand deliveries when needed. They value us as a technical resource as well as a product supplier.”
According to Richard Rhorer, NIST mechanical engineer, “The first time we tested the instrumentation system in a replica chamber, it worked perfectly. We’ve closely monitored the encasements after initial installation on Constitution Day in 2003. Based on this testing, we expect the interior environment of the encasements to be maintained at exacting levels for 100 years or more.” For additional facts and history on the Charters of Freedom, visit www.nist.gov or www.archives.gov. |
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