`Power Plant Heat Exchanger Tube Sheet Joining`

$50M utility heat exchanger; tube-to-tube-sheet joint made by explosive welding rather than arc welding because of the 10,000-joint count. Tapered hole + internal charge + 10–15° angle = explosion-welded seal.

Explosive bonding has found a lot of niche applications. One is building tube sheets. All the utilities have great big heat exchangers in their power plants. They have a great big tube sheet — could be 10 inches thick steel. They drill a bunch of holes, anywhere from 3/4 inch to a quarter inch, and put tubes in them. One of these tube sheets could be the size of this room — a big circular disc, 10 inches thick steel, with 10,000 holes in it. Each pipe might be 100 feet long. That's going to be one end of a great big heat exchanger. You flow water through, generate steam in your nuclear reactor or coal-fired plant, and transfer heat through your turbine to generate electricity.