Company: Spiralock Corp.
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Innovative Clamp Nut
V-Band Clamp Keeps Turbos Sealed Under Extreme Heat and Pressure, Prevents Exhaust Leaks
The V-Band clamps that seal off hot
exhaust so turbochargers can force compressed air into the intake may be
compromised if traditional fastening nuts loosen in the extreme heat and
vibration of the turbocharger environment.
With exhaust temperatures reaching
up to 1,300 °F, the V-Band Clamp assembly could quickly be compromised if the
exhaust leaks. With component temperatures reaching up to 1,000 °F around the
turbocharger, nut locking features using adhesive or nylon rings
For this reason, plain metal
V-Clamp nuts are typically usedbut as soon as they lose tension they can start
to back off, which can raise performance and warranty issues.
To keep turbochargers sealed and
prevent exhaust leaks, truck and auto engineers are turning to the V-Band Clamp
Nut called Spiralock, developed by Spiralock Corp. Its unique internal thread form is helping
the truck and auto industry withstand extreme turbocharger heat and vibration,
while reducing cost, assembly, and warranty issues. This re-engineered thread form adds a unique
30-degree wedge ramp at the root of the thread which mates with standard
60-degree male thread fasteners.
The wedge ramp allows the bolt to
spin freely relative to female threads until clamp load is applied. The crests of the standard male thread form
are then drawn tightly against the wedge ramp, eliminating radial clearances
and creating a continuous spiral line contact along the entire length of the
thread engagement. This continuous line
contact spreads the clamp force more evenly over all engaged threads, improving
resistance to vibrational loosening, axial-torsional loading, joint fatigue,
and temperature extremes.
When a major heavy truck turbo
manufacturer was breaking T-bolts driving a clincher nut that galled on a
V-Band Clamp assembly previously, they had to take the turbo off the production
line to repair. Switching to the
free-spinning Spiralock V-Band Clamp saved them the loss of about 15 V-Band
Clamp assemblies per day at the plant, eliminating related production downtime
and remanufacturing cost.
For detailed test data, including
comparative graphic loading characteristics or photoelastic analysis/load
vector comparison animation, visit Spiralock at www.spiralock.com
; call (800) 521-2688; fax (248) 543-1403; or
write to Spiralock at 25235 Dequindre Rd., Madison Heights, MI 48071.