Specifically formulated for use in high temperature and high-pressure environments, LOCTITE® NS 5540 and 5550 are sealing compounds that cure in the presence of heat to form a mechanical seal on metal-to-metal flanges and fittings. They are designed to allow for disassembly during routine maintenance and can also be used as a gasket dressing to extend the service life of traditional gaskets.
LOCTITE NS 5540 is a single component, high strength, product whose low viscosity makes it easily brushable onto flanges or threads. It is suitable for sealing flanges up to 20MPa (2900 psi). For higher pressure requirements, up to 34.5MPa (5000 psi), LOCTITE NS 5550 is recommended. This product is a thermal reactive, heavy bodied, fibrous paste that fills large gaps by expanding upon cure. Both products have a service temperature rating of 30°C to 700°C.
These new additions are unaffected by thermal cycling and provide an immediate, low-pressure seal before curing to create a high-pressure, temperature and chemical resistant seal. They are suitable for sealing steam, hydrocarbons, gases and other process fluids typically found in power generation facilities, pulp and paper mills, mines and oil & gas refineries.
Likely applications for LOCTITE NS 5540 are sealing threaded fittings, pump and turbine case flanges, doors, boiler sight glasses and for repairing leaking gaskets. As well as sealing case flanges, LOCTITE NS 5540 is the best choice for duct flanges, exhaust systems, pipe connections and pressure vessels.