Well-Planned is Fast Done – Sewer Rehabilitation During Ongoing Operations of a Food Processing Company
That the legally mandated internal monitoring is anything but a „toothless tiger“ and that companies take their responsibility seriously was impressively demonstrated by a carcass-disassembly plant. During a camera inspection, three sections with a nominal diameter of DN 300—two measuring 40 meters and one measuring 20 meters—were identified as defective. In each case, the pipe invert was affected, having been significantly attacked or „eaten away.“ The cause is attributed to acidic cleaning agents used to maintain high hygiene standards along the entire processing chain. Such chemical loads on drainage infrastructure are by no means rare, particularly in food-processing facilities.
Repair in a Tightly Scheduled Operational Environment
Production facilities are permanently under pressure to maintain their ability to deliver. Stoppages of individual sub-sections in the disassembly chain are economically hardly justifiable. Sewer rehabilitation during ongoing operations is therefore only possible during clearly defined maintenance windows—frequently on public holidays, bridge days, extended weekends, or, if necessary, even at night.
The originally planned execution date of February 16, 2025, could not be met because an essential component for the measure—the liner—was not available in time. Friday, May 2, 2025, a bridge day, was set as the new date.
The actual work could not begin until around 12:00 PM—meaning it was foreseeable that part of the measure would extend into the night hours.
Preparation: High-Pressure Cleaning and Reprofiling
Preparation: High-Pressure Cleaning and Reprofiling
The rehabilitation began with intensive cleaning of the affected sections using a flushing vehicle at 150 bar. A clean, load-bearing surface is a prerequisite for any sustainable repair.
Subsequently, ReproLining 0.5 from Hermes Technologie was used—a method for the targeted reprofiling of the damaged pipe invert.
In this process, a steel cable is guided using a winch from the target manhole via a deflection pulley to the starting manhole. A reprofiling device is attached to this cable. Before the operation begins, the repair mortar—in this case, the XWW3-certified ERGELIT-KS 1—is positioned in front of the device.
The reprofiling device is then pulled through the section in a controlled manner. The mortar can thus flow specifically into the washed-out and undermined areas of the pipe invert and seal them flush with the manhole wall. The operation is considered complete as soon as the exact amount of mortar introduced at the starting manhole emerges at the target manhole—a clear quality criterion for complete backfilling.
It was particularly favorable for this project that there were no lateral inlets in the immediate invert area. Such connections would have slowed down the process, as work would have had to be carried out with reduced mortar quantities.
By 10:00 PM, the section was successfully completed—both technically and organizationally, a bullseye.
Sustainable Liner Preparation Without Preliner
The performed reprofiling served as a preparatory measure for the liner. By restoring a load-bearing and uniform invert, the use of a preliner could be dispensed with.
This not only reduces material usage but also avoids microplastics—an aspect of growing importance that is equally welcomed by clients and contractors alike.
The project was successfully executed within the specified time frame. The close coordination of all parties involved paid off: both the client and the executing company were very satisfied with the result. Liner installation took place as scheduled on the very next day.
