Written by Valley Forge’s James Brooks
Controlled bolting has for many years been associated with critical bolted joints. The term is more often applied to the act or procedure of installation than to the life cycle of the bolted joint.
Application, measurement and control of torque has also been the predominant challenge for users of controlled bolting methods.
Installation methods have been designed to deliver torque-based final results. They have required the use of tooling with controlled output settings and with highly specific procedures in an effort to deliver reliable, repeatable (word choice? replicatable/reproduceable) clamp loads.
A shift in thinking to controlled bolting is taking place in many industries:
The use of direct tension measurement and control, versus torque, is growing. Inherently more accurate, tension control only uses torque as the “driving force” used to rotate and tighten a bolted joint. If measured directly, it can be used simply and quickly to manage torque-based equipment output.
But after the installation, can the bolted joint be controlled?
We do not have bolts that tighten themselves, yet, but using tension-based load monitoring fasteners is a reality. With the same benefit over torque, tension-based monitoring is more accurate.
Condition monitoring is the most costly part of controlled bolting. Factors include; inspection frequency, accessibility and equipment downtime, to name just a few.
The use of Valley Forge’s SPC4 tension indicating technology is playing a large part in driving these changes in controlled bolting installation and post-installation thinking.
Once installed, an SPC4 bolt or stud can be considered as the “foundation” from which a menu of interchangeable inspection options can be chosen. With a standard reading surface across all sizes of bolt or stud, different readers can be used as required or desired. They include:
- Manual, snap-on readers both in-line and right-angle.
- Wired electronic readers with data collection options and output control for torque tightening equipment operation.
- Blue tooth enabled readers.
- Hard-wired remote readers.
- Pre-programmed wireless readers for remote monitoring, including WiFi and Low Frequency options.
- Wireless Low Frequency readers that have internet user interfaces and can be programmed to send an alert if a bolted joint tension level is reached i.e. using the IOT, critical bolted joints can talk to you if they are having a problem: or are about to have a problem.
These options are taking the cost and complexity out of condition monitoring of critical bolted joints. They are now controlled for life.
Want to know more? Contact us today.
For more information or discuss what this means for your bolting application, please reach out to our sales team anytime at email@example.com.