Inspecting constant hangers and rigid holders in power stations has so far involved high personnel expenses. Technip, a globally operating plant manufacturer, uses HBM measurement technology to automate permanent load monitoring and thus ensure an increased level of safety and efficiency.
Piping in power stations needs to withstand considerable loads. Extreme temperatures and high pressure are not uncommon - conditions causing huge thermal strain and likely to overload the pipes. For this reason, so-called constant hangers are used for installing the pipes; they compensate for thermally induced movements.
However, force measurements on rigid holders are even more important. They permit integral evaluation of the load transfer by comparing the force differential between the cold and the hot state with preset values determined through system analyses carried out during the dimensioning of the plant. Deviations indicate imperfect load transfer (restricted movement due to the running of pipes, inadmissible hanger friction, distortion, etc.). Furthermore, force measurements on primary rigid supports enable the piping's current relaxation state to be assessed which is considered prerequisite to the required service life calculations on high-pressure piping.
Checking constant hangers and rigid holders in sensitive areas of a power station at regular intervals is already very complex and can only be carried out by well-trained specialists. Of course, the remaining risk resulting from visual inspection must not be underestimated: A false assessment might have far-reaching consequences.