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Cutting your load losses

Cutting your losses: “to extricate yourself from an impossible situation, where there is very little or no hope for improvement; walking away with nothing to show for your efforts”

A commonly used expression which is pretty much always seen as a negative conclusion to a situation.

Hydratight’s approach to dealing with load loss means you can cut your losses and walk away, confident in a job well done – and that’s very much a positive.

There are two main mechanisms that account for load loss in a bolted joint. In the first case, the joint itself loses load over time and this happens regardless of tightening method.

With tensioning, however there’s an additional factor which relates to how the tensioner itself works and by taking that into account, you can calculate how to compensate for the loss. Basically the tensioner works by gripping the extra thread protrusion and stretching the bolt (the force used here is referred to as the applied load). In a similar fashion to a spring, once the load applied by the tensioner is released the bolt will try to go back to its original length, with one of the consequences of this being that load is transferred from the tensioner puller sleeve and bolt to the nut and bolt. As this happens, actions such as thread deflection, surface compression and radial expansion of the nut cause a portion of the applied load to be lost, leaving what is referred to as the residual load.

Hydratight has been at the forefront of the development of bolt tensioning systems for over 30 years now and utilizes a method to compensate for this so, in effect, cutting your losses. Using very exacting calculations based on both theory and extensive in-house testing, Hydratight can accurately gauge what the loss will be based on any given joint configuration. From that it’s possible to determine how much extra load is needed to compensate for the tensioning process. In that way load loss can be accounted for in the calculations and added to the desired residual load value to determine the initial applied load.

Hydratight engineers can not only identify the most appropriate tightening method to be used on a project for each joint, but will advise customers on the right tools for the job. Hydratight knowledge and expertise help compensate for, and reduce, load loss.

Cutting your losses and being able to walk away from a job well done; no bad thing.