New at PipingDesign.com: 21 February 2001

Piping Design Central subscribers are up to 125, and steadily increasing. Thanks to all your support so far, I have big plans for this site. Still working on the pipingdesign.com web-based email addresses.

Paul

PS One way I fund Piping Design Central (aside from going into debt) is by doing web design. If you would like a few personal pages or a professional site created/hosted, contact me.

<a href="http://www.pipingdesign.com/welding.html">http://www.pipingdesign.com/welding.html</a>

Putting a Stop to Hot Work Losses (PDF Document) Brookhaven National Library

<<Cutting, grinding, brazing, welding, soldering, thawing pipe, applying roofing materials with torches- all examples of hot work-involve open flames, sparks or heat. A flame from an oxyacetylene cutting torch can reach up to 6,000°F (3,316°C). Sparks can fly or roll great distances and ignite combustible storage, dust accumulations or oily residues. Smoldering material hidden from sight can suddenly burst into flame long after work is completed and personnel have left the area. Heat conducted by hot work on one side of a wall can ignite combustible material on the other side. >>

<a href="http://www.pipingdesign.com/designinnovation.html">http://www.pipingdesign.com/designinnovation.html</a>

Revolutionary Low-Cost Joints
MTAC <<Surface irregularities, joint pressure extrusion, and stress relaxation can cause leaks in conventionally bolted and gasketed joints. Although liquid sealants can reduce leaks by filling surface imperfections, adhering to joint surfaces, and minimizing gasket thickness, process control is difficult, curing is time consuming, fumes introduce an environmental concern, and servicing can be difficult. Liquid sealants used in a highly finished joint can fail, resulting from sealant breakdown or extrusion. Brazed and welded joints eliminate some limitations and costs of bolted joints, but they increase undesirable process variability and hinder future disassembly. To address the limitations of these conventional joining and sealing technologies, NASA Marshall Space Flight Center developed new thermal joint techniques. For a typical installation, an electrically or thermally conductive substrate assembly is positioned in the joint under a preload and uniformly heated. An electrically conductive substrate is heated by passing an electrical current-either continuous or impulse-through it. A thermally conductive substrate is heated by connecting the substrate to an external heat source. Once the substrate is heated, some preload is released into the interface to complete the connection. The joint is fully cured within a few minutes after the heat source is disconnected from the substrate.
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Received on Wed Feb 21 23:38:00 2001