Interbolt
InterBolt technology enables you to measure the preload in bolted connections both onsite and remotely. This ensures bolts are tightened accurately onsite, eliminates the need for manual periodic inspection and enables asset failures to be predicted and prevented.
InterBolt Technology
InterBolt is a miniature, high accuracy and low-cost bolt load sensor embedded into a bolt or stud. The wireless, battery operated device enables bolt load to be measured both onsite and remotely.
Onsite Monitoring
To quickly verify bolt load, InterBolt provides two methods for monitoring bolt load onsite: inbuilt LED indicators on the InterBolt end cap and through wireless connectivity to the InterBolt Tablet App.
Remote Monitoring
To eliminate the need for bolts to be periodically inspected on site, bolt load measurements from InterBolt can be remotely monitored, in real-time with no technicians on site.
InterBolt Technology
InterBolt for bolt load monitoring
There is widespread agreement that the best way to ensure high integrity of bolted connections is to measure the bolt load. Historically, direct measurement of bolt load has required technicians to be on-site and the use of expensive, wired and fragile instrumentation so was unfeasible for many applications.
InterBolt features a high accuracy bolt load sensor embedded directly into the bolt or stud.
The technology provides:
- Real-time bolt load measurements to technicians during installation to ensure bolts are tightened accurately and repeatedly
- Remote monitoring of bolt load which eliminates the need for manual periodic inspection
- Continuous and high accuracy bolt load measurements to predict bolt failure, enabling preventative maintenance to be conducted.
How does it work?
InterBolt measures bolt load through measuring the elongation of the fastener under load.
Although it may seem counterintuitive to many, a bolt acts like a spring and is designed to stretch a small amount as it is tightened. This inherent bolt spring tension causes the clamping force which holds the joint together and prevents loosening during operation. The relationship between force and elongation is constant until a bolt reaches its yield point.
The sensing technology embedded in InterBolt measures bolt elongation (through the use of a gauge pin principle) and converts this to an accurate measurement of bolt load (otherwise referred to as clamping force). Every InterBolt is calibrated over its full load and temperature range so no on-site calibration is required. The InterBolt sensor is also not impacted by changes in effective length so it can be used without configuration for a specific bolted connection.
LED indicators
InterBolt features super bright LED indicators for simple and fast validation of bolt load. Simply wake up the device using a magnet and then look at the LEDs:
Flashing red – Bolt load too low
Flashing green – Bolt load in target range
Flashing Red/Green – Bolt load too high
Solid red– Bolt load is above proof load of the fastener and permanent elongation of the fastener is possible.
The LED indicators enable bolt load validation in seconds without the need for heavy or cumbersome tools, an external power supply and complex setup procedures. Even without a clear line of sight to the end cap, the LED indicators can be seen from 20m away.
Onsite bolt load monitoring
As well as the embedded LEDs, InterBolt can connect to the InterBolt Tablet during tightening activities to visualise bolt load. The InterBolt Tablet solution enables bolt load measurements from multiple sensors to be visualised in real-time.
The connection between InterBolt and the tablet is over the LoRa wireless network. The wireless communications still operate when used in conjunction with bolt tensioners or similarly obstructive tools.
Remote monitoring
InterBolt periodically transmits bolt load data to a remote network via the InterBolt Gateway. This enables remote access to real-time, autonomous bolt load samples, eliminating the need for technicians to be on-site.
Each InterBolt Gateway can connect thousands of InterBolts and is typically limited by the range of the wireless network (typically 1km), rather than the number of devices.
In the InterBolt Cloud, bolt load samples are:
Stored. Bolt load samples from installation to decommissioning are stored so a full historic overview of the bolt life is known.
Analysed. The cloud system features simplistic analytics engines which can generate an alert when the bolt load exceeds a predefined threshold or is trending towards a certain state.
Visualised. The cloud features a huge range of visualisation options: from visualising the bolt load from a single sensor, to overlaying the status of bolts on a 3D model of the asset.
Battery life
InterBolt features a battery solution in the end cap. The battery can power InterBolt for up to 15 years, with no maintenance required.
Once the battery is depleted, it can be exchanged as part of the end cap in less than 30 seconds without the need to loosen the bolt. Simply remove the two end cap screws and replace the end cap.
Wireless range
InterBolt utilises LoRa wireless communications to transmit bolt load data to the InterBolt Gateway for remote monitoring and InterBolt Tablet for onsite monitoring.
LoRa uses an optimised modulation technique (spread spectrum) for long range, low power wireless communications. InterBolt couples a LoRa PHY level with a high efficiency antenna and a self-learning adaptive channel optimisation protocol. The result is a wireless range of up to 1km, whilst still having a battery life of up to 15 years.
Through having a long-range wireless solution, typically only one InterBolt Gateway is required to get full connectivity over an asset. Other solutions often have much lower wireless range which results in additional hardware costs for multiple gateways/repeaters and additional deployment cost and effort to provide power to each of these.
InterBolt Accuracy
InterBolt features the best-in-class sensor accuracy at 95%. The maximum 5% error includes errors due to hysteresis, non-linearity and repeatability. The proprietary bolt load sensor inside InterBolt features component ageing and temperature compensation so InterBolt will maintain its specified accuracy over the full operational temperature range and over its full operational life.
Each InterBolt is calibrated at manufacture and is supplied with a calibration certificate.
Any bolt, any stud, any industry
InterBolt is available in a wide range of bolts and studs. Whilst it is typically applied to large diameter fasteners – M24 or 1’’ and bigger, the technology has been applied to bolt diameters down to M10.
InterBolt is often embedded into free-issued bolts from our customers but InterBolt can also supply the fasteners through approved European suppliers.
Onsite Monitoring
Historically, direct measurement of bolt load has required the use of expensive, wired and fragile instrumentation which are prone to human error. The InterBolt system provides two methods of onsite monitoring: embedded LEDs and the InterBolt Tablet Application. These solutions enable technicians to accurately and precisely measure the load of multiple bolts in seconds, without the need for complex setups and the use of heavy or cumbersome tools.
Embedded LEDs
InterBolt features super bright LEDs in the end cap for simple and fast verification of bolt load. The LEDs represent how close the measured bolt load is against the target load of the application. Simply wake up the device using a magnet and then look at the LEDs:
Flashing red – Bolt load too low
Flashing green – Bolt load in target range
Flashing red/ green – Bolt load too high
Solid red – Bolt load is above proof load of the fastener and permanent elongation of the fastener is possible.
The LED indicators enable bolt load validation in seconds without the need for heavy or cumbersome tools, an external power supply and complex setup procedures. Even without a clear line of sight to the end cap, the LED indicators can be seen from 20m away.
The bolt load thresholds for the LEDs can be configured onsite using the InterBolt Tablet and alternative LED colours are possible for specific applications.
InterBolt Inspect App & Tablet
InterBolt Inspect App
The InterBolt Inspect App is used to visualise bolt load data on site and provides higher precision bolt load measurements than the embedded LEDs.
The app features three main views:
- List view – where the bolt load from multiple InterBolts can be viewed
- Single view – where the bolt load from a single InterBolt can be viewed in more detail.
- Configuration view – where the configuration of the InterBolts can be updated
The data captured by the InterBolt Inspect app is stored and can be downloaded.
The app is typically hosted on the InterBolt Tablet – a ruggedised Android tablet – but app versions are also available for Windows and IoS devices.
InterBolt Tablet
The InterBolt Tablet is a ruggedised Android based industrial tablet with inbuilt LoRa transceiver. This enables it to communicate with InterBolts over their wireless channel at a range of up to 100m.
The tablet is designed for harsh operating conditions with ingress protection rating to IP67, impact protection to IK07 (drop resistance to 1.2m) and operates over an extended temperature range of -200C to 600C. The 10-inch capacitive touch screen works in direct sunlight and the tablet has a 12-hour battery life.
Various mounting hardware is also available including a shoulder strap, hand strap, VESA mount and docking station.
How to activate
To preserve battery life, the InterBolt only enters onsite monitoring mode when it is activated by a technician. To activate InterBolt, simply wave a magnet over the area near to the LEDs (shown in red). The InterBolt LEDs will then illuminate and it will begin transmitting data which can be captured by the InterBolt Tablet to visualise bolt load. The time in local monitoring mode and the sampling rate in this mode is user configurable.
When not in onsite monitoring mode, the LEDs will not illuminate and InterBolt will periodically transmit data (typically once an hour) to the InterBolt Gateway for remote monitoring.
Remote Monitoring
Checking the tightness of bolted connections typically requires manual tools operated by on-site technicians which is prone to human error, costly, results in asset downtime and presents several health & safety risks. With the InterBolt Gateway and Cloud system, the tightness of bolted connections can now be remotely monitored in real-time, therefore eliminating the need for onsite inspection.
InterBolt Gateway
The InterBolt Gateway connects InterBolt sensors to a remote network to enable continuous and autonomous bolt load monitoring without the need for technicians to be onsite. Specifically, it is a data concentrator and gateway used to capture data from InterBolts over the local LoRa network and forward this to either the InterBolt cloud system or a third-party cloud system over an Ethernet, Cellular or Satellite connection.
The InterBolt Gateway is designed for harsh environments, with an ingress protection rating of IP67. There are various mounting options including; pole mount, VESA, magnetic or DIN rail mount to suit any application.
The InterBolt Gateway is ‘plug and play’ but also features an embedded web server for management and setup.
InterBolt Cloud
The InterBolt Cloud is the platform that Operations teams use to remotely monitor bolted connections.
In the InterBolt Cloud, bolt load samples are:
- Stored. Bolt load samples from installation to decommissioning are stored so a full historic overview of the bolt life is known.
- Analysed. The cloud system features simplistic analytics engines which can generate an alert when the bolt load exceeds a predefined threshold or is trending towards a certain state.
- Visualised. The cloud features a huge range of visualisation options: from visualising the bolt load from a single sensor, to overlaying the status of bolts on a 3D model of the asset.
For organisations with established condition monitoring systems, the InterBolt data can also be integrated into third-party systems either at a ‘Gateway level’ through its configurable endpoints or at a ‘Cloud level’ through an API.
Historical bolt load
To analyse the long-term performance of a bolted connection, all bolt load samples captured from installation to decommissioning are stored in the cloud platform and can be viewed through the historical bolt load graph (pictured). This enables engineers to:
- Assess the bolt load achieved at installation to ensure bolts are accurately tightened.
- Quantify any settling and embedding losses which may occur over the first few weeks post installation.
- Identify any vibration induced loosening or fatigue failures which may occur in the mid to long term.
The historical bolt load graph provides context around the bolt load measurements with the thresholds which would generate an alert overlayed as shown by the amber and red bands on the graph. Maintenance events (M in a circle) are also displayed to provide further insight as to any events which may lead to a sudden change in bolt load.
3D modelling
The InterBolt Cloud is an asset-centric platform that attributes bolt load measurements to a specific location on the asset. With this location data, we can overlay the bolt load data onto a 3D model of the asset itself. This helps Operations teams know exactly where the fault has occurred as well as helping them understand any impact on bolts in the near vicinity.
The InterBolt Cloud platform features a large range of 3D models from wind turbines to bucket excavators.
Actionable maintenance insights
The InterBolt cloud platform features a simplistic analytics engine which can generate an alert when the bolt load exceeds a predefined threshold or is trending towards a certain state. Each alerts gives a clear overview of the fault type along with positional information for where the fault has occurred. All alerts link directly to the bolt load graph so users can graphically see the current and historic performance of the connection.
The alert thresholds are configurable on an individual bolt basis through the cloud platform. Different severity alerts can be generated to help Operations teams understand the urgency of the remedial maintenance.
The alerts generated in the cloud can also be sent to key stakeholders via email or SMS, to minimise the time between detection of a critical issue and remedial action being taken.
The alert feature ultimately means that Operations team don’t have to look at the bolt load reported by each InterBolt periodically to identify an issue. Instead, the cloud platform does this autonomously and provides maintenance insights which Operations teams can action.
Digital maintenance records
The InterBolt cloud incorporates digital maintenance records so that a full history of onsite activities from installation to decommissioning can be documented and correlated to bolt load measurements.
In the historical bolt load graph, maintenance events are displayed on the x-axis giving a clear description of the maintenance activity, timestamp and technician involved.