Thermal Gasket Developed At Marshall

Marshall Space Flight Center seeks qualified companies to further develop and commercialize a new gasket technology. This gasket consists of an electrically conductive substrate coated on both sides with a thermoplastic or braze alloy. When the substrate is heated, by an electrical current passing through it, the coating melts. Preliminary tests have shown that this low-cost technology can fill imperfections and adhere like a liquid sealant or braze, creating a zero-leakage joint that can easily be disassembled for service.

The thermal gasket could be used in a wide variety of static sealing applications for flanged piping and housing joints; particularly where there may be imperfections in the joint and future disassembly is a priority. Several proof-of-concept gaskets have been fabricated, and one test has been performed. A 0.007-inch-thick, mild steel substrate was coated with a standard hot melt adhesive using a commercial applicator and then positioned between two 2-inch flat-faced carbon steel pipe flanges under a light preload. A 220-volt commercial arc welder was connected to opposite ends of the substrate and drew approximately 200 amps of current for about 2 minutes. The thermoplastic melted, and four flange bolts torqued to approximately 65 ft.-lbs. The current was disconnected and the joint allowed to cool. The completed joint was pressurized, then depressurized for further leak testing. No leaks were found. The gasket can be remelted in situ for easy joint disassembly. It offers stability, quickness, ease of use and low ignition risk.