The BoltLife procedure provides efficiency and accurately closed flange connections. As opposed to the traditional methods, the preload is measured in kN. The effects that cause spread in the preload of flange connections are eliminated or controlled to the highest extent. The result is a connection with a spread of less than 10% and a pre-load above the required minimal load on every bolt. In addition to this, measuring bolt tension also allows for a higher preload without the risk of over-stretching the bolts.
BoltLife provides bolting related support in flange design. The majority of challenges when it comes to preload in a bolted connection, are related to the design. If specific tooling techniques can be applied, the accessibility of the bolts in the connections and accessibility for measurement purposes, is already determined in the design phase. Small adjustments in the design can therefore lead to major savings in the execution phase of a bolting project.
Creating a specific bolting plan for a project, guiding implementation, supervision of the execution, execution of measurements, provision of project specific equipment and verification of the generated data. It takes time to set this all up, so the phase in which BoltLife gets involved in a project determines to what extent process optimization can be achieved. The procedures and guidance are adjusted to the customer's requirements. At the end of a project BoltLife provides an extensive final report.
BoltLife developed a technique that allows us to determine the current pre-load in bolts in a connection, even when load measurement techniques have not been applied when preloading these bolted connections. Our consultants perform specific on-site tests. Based on these results, BoltLife can accurately determine the preload in the tested bolts in our lab. Using this information, BoltLife can create a theoretical projection of the pre-load in the tested bolted connections. All our measurements are made in kN pre-load.
Re-bolting projects demand a different approach in execution than new projects. In general, BoltLife deals with the question whether the current bolts in the connection can be reused or need to be replaced. These bolted connections are part of a construction which makes it more challenging to exchange and pre-load the bolts without disassembling the entire construction. BoltLife offers tailor made solutions for these re-bolting projects.
In performing high quality ultrasonic measurements, it is important to equip the measurement tools with accurate settings. This differs for every individual type of connection and bolt size. Because most bolts in wind turbines are produced for a specific purpose, these settings are unique and can vary per batch. This requires unique verification for every situation and bolt-flange combination to guarantee accurate load measurements. BoltLife has set up a laboratory specifically for this purpose. BoltLife uses traceable and calibrated equipment and a specially developed procedure to determine these settings.
BoltLife processes the generated data from projects during its execution. This entails that all performed measurements are evaluated and deviations will be communicated to the responsible people on the project. Through this procedure, possible failures are corrected immediately and deviations from the performance standard are noticed directly. Extensive quality control or recovery practices are therefore limited.
One of the mayor advantages of measuring bolt tension is that, if the bolts remain in the same position in the connection, the actual pre-load can be measured at any point in time. Re-measurements are made using only the MAX II device with the database created during the pre-loading of the flange. Based on these measurements, a dynamic maintenance plan can be established. In this plan, the interval and the number of flanges to be measured will be adjusted accordingly. Because all flanges were preloaded using the same procedure, it is possible to select a number of flanges that represents the entire set of flanges in the project. This provides huge savings on maintenance costs while guarantying high quality.
Depending on the project execution, BoltLife can offer training on performing measurements with our measurement equipment. This training, depending on level and purpose, will provide more knowledge on bolts and bolted connections for technicians in the field. The training will be adjusted to the specific demands for each individual project.