Measuring Flanges using a Laser
Flanges are essentially joint components and as such, they must be fabricated accordingly. This is a must if, for example, gaskets are to seal properly, or the joints are to be free of tension after assembly. Achieving perfect geometrical results, especially in the fabricating of tower sections is not an easy task; tension occurs throughout the welding process, which can lead to an uneven flange surface and ultimately to a less than satisfactory joint result. Being able to measure and react to these imperfections means being able to ensure a long and trouble free service life of the joint.
Up to date, measurements were made using straight-edges and feeler gauges. This method loses practicability with increasing flange diameter. As measurements with straight edges can only be carried out in “segments” of the flange, the results are displayed as short waviness and not of the flange as a whole. A new method had to be found! When using a Laser plane (rotating laser) it becomes possible to measure the whole flange against this reference plane. To enable this, the Laser is mounted on or next to the flange. The Laser projects the plane over the flange and through using the R310 Receiver, the distance between flange surface and Laser plane can be quickly measured and documented.
Various procedures can be used:
- The Laser plane is set up using 3 points on the flange, in other words parallel to the flange
– this method is time consuming and the result depends on which points are chosen
- The laser plane is set up at an angle to the flange
– this is much quicker but on the other hand, calculations are necessary to achieve correct results.
Modern measurement systems achieve this on-site in real time whereas older systems require a