An
update on anaerobic thread treatment.
Commonly used as threadlockers, thread sealants and
retaining or gasketing materials, anaerobic adhesives can help manufacturers
and maintenance personnel decrease total manufacturing or operating costs and
enhance equipment reliability. These
liquid adhesives cure or solidify when restricted from oxygen in the presence
of metal ions. As they contain no
volatile solvents that evaporate out of the threads over time, they will not
shrink and affect the long-term performance of the sealed joint.
New Technology
Early anaerobic threadlockers were effective at maximum
continuous operating temperatures of 300
SIDEBAR: Anaerobic Glossary
Threadlocking adhesives – These
adhesives fill the grooves of threads and cure to a hard thermoset plastic that
locks threads together, preventing unwanted movement/loosening and
leakage/corrosion. They offer high shear strength, very good temperature
resistance, rapid cure, easy dispensing and excellent vibration resistance.
Threadlocking adhesives are a reliable and inexpensive way to ensure that a
threaded assembly will remain locked and leak-proof for its entire service
life.
Thread sealants – These easy-to-apply products
block the naturally occurring leak path located where the crest and the root of
a pipe thread meet. Once cured, these materials seal and lock threads. During
assembly, they act as a lubricant to promote tightening while ensuring consistent
assembly torque.
These materials provide instant low-pressure (500 psi) seals, and many
formulations will seal to pressures of 10,000 psi after cure. Thread sealants
can seal pipe unions and compression fittings, and provide exceptional fluid
compatibility and sealing ability.
Retaining compounds – Anaerobic retaining
compounds are applied to the inside and outside diameters of parts, and enable
rigid cylindrical assemblies to be bonded with adhesives rather than by
mechanical means, such as press fits or shrink fits. Once cured, retaining
compounds offer high adhesion to metal surfaces through mechanical interlocking
and chemical bonding. Retaining compounds are used to assemble clearance, slip
and interference fits. They also fill imperfections and augment fits on worn
shafts and slip fits.
Formed-in-place anaerobic gaskets and flange sealants
– These materials produce leak-proof seals between mating flanges, preventing
leakage of moisture, gases, fluids or contaminants. Formed-in-place gaskets and
sealants fill the surface roughness between mating metal parts and add
structural strength to an assembly. In their uncured state, anaerobic gaskets
and flange sealants flow into the microscopic surface irregularities on metal
substrates and fill the voids between flange faces. When cured, they unitize
the assembly, withstand thermal expansion of the mated parts and resist a range
of chemicals. These materials can be applied to any size flange, minimizing cut
gasket inventories.
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