HEICO Fastening Systems  

HEICO-TEC® mechanical tensioners offer considerable advantages for tensioning large bolted joints quickly, simply and reliably.    

Product family include tension nuts and bolts in both standard and custom sizes.

With only a standard torque wrench, a technician on the factory floor or in the field can accurately tighten the largest bolted joint with no torsional influence on the primary bolt threads avoiding thread deformation and resultant loss of preload, durability and reusability of the bolt. 

Features and Advantages:

- Direct replacement for same sized and grade heavy hex nut.

- Tightening large bolted joints in cramped locations (e.g. nacelle) is problematic if using large, heavy tensioning or torque tools.  If a standard "human-powered" torque wrench can fit into the space, then the HEICO-TEC can properly tension the bolted joint.

- Two part pressure assembly consists of a pressure bolt and a pressure pin.  Pressure pin does not induce negative torsional impacts on the hardened washer avoiding galling and other damage common to similar products.  

- Arrives at the site pre-lubricated from the factory.  No time, expense or mess needed for onsite lubrication.  Pre-lubrication ensures stability in tightening accuracy.

- Due to design improvement, pressure bolt lubrication is protected within the bore with no direct exposure to the elements.

- Precise.  Tightening and reuse accuracy is guaranteed.  Confirmed by DNV-GL.

- Reusable. No damage to assembly during tightening/loosening.  No torsional stress introduced on tightening so no bolt thread damage.

- Fast. No special tools required aside from a standard wrench and socket.  Avoids cost and setup time of other traditional tensioning methods such as hydraulic tightening.

- Complies with all ISO 898-2 and relevent ASTM requirements.  DNV-GL verified proof load testing. 

- HEICO-TEC® Reaction Nut used on the passive end of a threaded rod joint, opposite of the Tension Nut.  Reaction Nut increases the elasticity of the bolted joint and equalizes load distribution amongst engaged threads.

- Standard inch/metric sizes stocked. Custom sizes/materials available.

- Available in either uncoated or our standard zinc-flake protective coating.

Self-loosening of critical bolted joints can result in extremely negative situations: machine damage, loss of revenue, work stoppages and even harm to personnel.  Power generation applications are especially sensitive to bolted joint self-loosening due to a variety of reasons.

In a wind turbine, vibration and dynamic loads are present throughout the assembly and impact all bolted joints: pitch bearing flanges, blade and yaw flanges, generator, gear box, brake assemblies, rotor, couplings, ladders, cranes, hoists, etc. 

In solar power applications, all of the steel connections dependent on bolted joints suffer exposure to wind loads.  Over time, transverse influences or vibration creates slippage between bolted parts and ultimately within the bolted joint itself.  This leads to bolt loosening and the real potential for damage.  Single axis trackers and pedestal mounted trackers are especially prone to bolted joint self-loosening.    

How does the HEICO-LOCK^® Wedge Lock Washer work?  When the bolt is tightened, the external radial teeth of the HEICO-LOCK^® Wedge Lock Washer imprint themselves in an interlocking fashion in the respective mating surface.

If the bolted joint is subject to dynamic stresses, movement is only possible between the wedge lock washer’s internal wedge shaped washer surfaces. Since the wedge angle is greater than the angle of the bolt’s pitch thread, self-loosening potential is eliminated.

Characteristics:

- Qualified and proven by numerous power generation OEM's, sub-suppliers and global certifying agencies.

- Locking performance not dependent on lubrication.

- Effective bolt security confirmed even under low initial preload - whether by design or operator error.

- Can be reused.  No need for expensive tools to remove; bolted joint can be loosened with normal tools.

- Easy to install.  No need for single use, expensive installation tools.

- Suitable for up to 12.9 strength class and grade 8 bolts and their respective nuts

- Available in steel, stainless steel, SMO 254 and Inconel 718, in both narrow and enlarged OD’s

- Heavily stocked in Hickory, NC in standard sizes up to 3” and M76

- Custom sizes and coatings available to meet OEM specifications.