3D laser scanning for dimension control

Replacement of industrial condensers is a complex operation because they are usually installed deep within the factory; and when they are 8 metres long and weigh 53 tons, expert help is essential, especially when working to tolerances of only a few millimetres.

Using 3D laser scanning Fugro produced digital models of the two installations, including the surrounding steel, concrete and piping. These models were used to identify the best routes for removing the existing condensers and installing the new ones; also to determine which parts of the plant had to be dismantled or demolished to carry out the project.

On the top side of the condensers is a large, rectangular flange, which is joined to a turbine by a connecting piece. The turbine did not need to be replaced, so the new condensers were to be installed under the existing flanges of the connecting pieces. To minimise the infilling between ‘old’ and ‘new’ and to complete the project as quickly as possible, dimensional accuracy had to be guaranteed to the nearest millimetre. We produced highly accurate measurements of the flanges of the old condensers and the connecting pieces beneath the turbines.

The manufacturer of the new condensers used the data to verify the drawings. We carried out interim tachymetric control measurements on the newly built units enabling the production of a report using AutoCAD (dimension control) immediately after the on-site measurement. Once the condensers were ready, a ‘final as built’ measurement was carried out by performing a laser scan of the whole system and making tachymetric measurements of key points.

In the factory, a local survey base network was created and specific final checks were carried out to determine exactly how much infilling would be necessary after the condensers were installed. We then placed a 3D model of the new condensers into position in a 3D visualisation. The data yielded by this process were relayed to the local base at Shell and served as a reference for our team and operators from the transportation company for the installation process.

Following our instructions, the two condensers were slid into position at the Shell plant within a single day. The positional accuracy was less than 2 millimetres and the height accuracy less than half a millimetre - within the client’s specifications. Thorough checking and measuring beforehand meant that less reworking was needed on site, thereby increasing safety and reducing turnaround time.

How we can help you

Our specialised laser techniques produce highly accurate data and 3D visualisations for industrial installations. Ask us how.