LOCTITE® NS 5540 Extreme Temperature Sealant

LOCTITE® NS 5540 is a brown, high strength, heat-cured liquid sealant for threads and flanges in high temperature and high pressure applications. The cured product won’t permanently join flanges together, better enabling any future repairs of metal-to-metal joints, and performs well under thermal cycling conditions. It has a top service temperature of 1,300°F (700˚°C) and has been successfully used to seal flanges carrying up to 2900 psi steam. Typical applications include high-temperature thread and flange sealing of steam, oils, hot air, and exhaust gases.