Bolt Tension Monitors are instruments designed to monitor stresses on threaded fasteners. Threaded fasteners are one of the most versatile methods for assembling structural components.
Most industrial environments contain hundreds, if not thousands, of bolts holding machinery and equipment in place. When nuts and bolts are fastened together under load, the action of
tightening the nut increases the force applied to the bolt causing elongation and stress which can lead to failure resulting in leaks, costly downtime, and potential safety hazards.
The health of bolted joints is defined by a single parameter: the clamping force (CF). The CF is the force that holds the elements of the joint together. If the CF is too low, separation and bolt
fatigue may occur. On the other hand, excessive CF may produce damages in the structural members such as excessive distortion or breakage.
The most common method of monitoring these critical bolts for tightness is to physically inspect each bolt and take a mechanical torque reading. At best, this is an imprecise way of measuring
tightness due to the various conditions of the bolt threads, and the accessibility of the bolt itself.
Bolt tension monitors are highly sensitive ultrasonic meters that measure bolt load, elongation, stress and percentage of strain by determining the change in the transit time off an ultrasonic
shock wave along the length of the fastener as the fastener is tightened. Ultrasonic technology allows measurements unaffected by temperature, friction or resistance resulting in accuracies to
within 0.0001mm (0.00001 inch). Such high sensitivity provides insight to the health of the bolted joint and early alert to potential failure.
Typical applications for bolt tension monitors:
- Heat exchanger girth flanges
- Pressure vessel girth flanges
- Valve flanges
- Boiler pump flanges
- Reactor manways
If you have any questions regarding bolt tension monitors please don't hesitate to speak with one of our engineers by e-mailing us at sales@instrumart.com or calling 1-800-884-4967.
