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Company: Spiralock Corp.
www.spiralock.com

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 used—but 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; email slinfo@spiralock.com; call (800) 521-2688; fax (248) 543-1403; or write to Spiralock at 25235 Dequindre Rd., Madison Heights, MI  48071.