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Product description:
LOCTITE NS 5540 is a thermal reactive liquid sealing compound that is used in high temperature and high pressure applications. In the presence of heat, LOCTITE NS 5540 will cure to form a seal. LOCTITE NS 5540 will not permanently join the flanges together, it will not interfere with future repairs of metal-to-metal joints. This product is typically used at temperatures up to 704°C (1,300°F) and seals up to 200 bar (2,900 psi) with correctly designed flanges. Further information on the product can be obtained from your local technical department:

Directions for use:
1. For best results, clean all surface (external and internal) with a LOCTITE SF 7063 cleaning solvent and allow to dry.
2. Apply an even coating across the entire surface to be sealed with a brush or putty knife (apply to male end of threads).
3. Product may be used with existing gaskets as a dressing. In this case apply a thin coat to both sides of the gasket as well as the matting surfaces.
4. Normal bolting and torque procedures should be followed when assembling the joint, follow manufacturer's specifications where required.
5. Product may be used with existing gaskets as a dressing. In this case apply a thin coat to both sides of the gasket as well as the mating surfaces.

6. High pressure applications or pressure testing at ambient require running heat without pressure or pre-curing with an external heat source.

7. Immediately after use clean tools with suitable cleaner, e.g. LOCTITE SF 7070 or a solvent such as acetone or isopropyl alcohol. Once cured, the material can only be removed mechanically.

The product is classified as combustible and must be stored in an appropriate manner in compliance with relevant regulations. Do not store near oxidizing agents or combustible materials. Store product in the unopened container in a dry location. Storage information may also be indicated on the product container labelling.
Optimal Storage: 8 °C to 21 °C. Storage below 8 °C or greater than 28 °C can adversely affect product properties.
Material removed from containers may be contaminated during use. Do not return product to the original container. Henkel cannot assume responsibility for product which has been contaminated or stored under conditions other than those previously indicated.

  • Chemical type : thermally reactive resin
  • Appearance : brown liquid
  • Cure : heat cure
  • Density at 25 °C, g/ml : 0,968
  • Viscosity, mPa·s (cP) : 48,450
  • Lubricity, K-Factor : 0,14
  • Cured for 24 hours (23 °C):
    -Breakloose Torque, ISO 10964, Pre-torqued to 290 N·m ,1.25 inch B-7 Bolt, N·m : 217

Full technical information can be found in the technical data sheet.