We ensure through careful repair that the flat and spiral ducts which are used for many years in mining and tunnelling, regain their full performance. Of course the repairation is less expensive than the production of new ducts. Repairation can be repeated several times.

		Delivered ducts before repairing.

Each defficient duct is initially examined. If it has strong dammaged (through stone impacts or through material defficiencies) we recommend a disposalor distruction. Fortunately this was not often the case. After careful sorting the ducts are thouroughly cleaned. For this we use heated and micro jet water under 100 bar and without further chemical aditives.

As the cleaned ducts have dried up, 8000 pascal pressure test is conducted. Holes of all sizes down to needle size and hair cracks are detected realiably by scanning and than marked. Consequently the marked holes are sealed by cover material, welded with 700 C air flow device. In such way a homegenoius connection is achieved on each covering sheet in which the PVC coating is connected to the grid fabric.

The repaired duct than undergoes a pressure test, which is consistant with the norms DIN EN ISO 9001-2006 for .

		Repaired duct ready for delivery