Edge-welded bellows used in NASA's cryogenic chambers

On 7 October, 2012, NASA's Commercial Resupply Services (CRS-1) mission lifted off from launch complex 40 at the Cape Canaveral air force station in Florida, carrying a batch of frozen confectionery ice cream as a surprise for the three-member crew on board SpaceX's Dragon cargo capsule. The ice cream was stored on board in a Glacier freezer, which uses a BellowsTech edge-welded bellows assembly.

The Glacier (General Laboratory Active Cryogenic ISS Experiment Refrigerator) is used primarily to preserve science samples that require temperatures between -160 and +4 degrees Celsius on the way to and from the International Space Station (ISS). The freezer, which is the same size as a mini-fridge, previously flew aboard the space shuttle.

A BellowsTech rectangular bellows assembly provides the mechanical seal between the Glacier's door and the refrigeration unit; once the door is shut there is a leak-tight seal to prevent temperature changes. At extremely cold temperatures, materials like rubber becomes brittle, but a mechanical seal achieved using a metal bellows assembly ensures survival despite the cryogenic temperatures inside the chamber.

Chris Cattle of Abssac Limited, the sole UK distributor for BellowsTech products, comments: "With the ability to customise size, shape, material, weight, length, and mounting connections, we can provide a solution to industry-specific application needs."

Follow the link for more information about edge-welded bellows.