Piping repair, avoiding pipe removal - by inserting inner tube in pipe and filling between inner and outer pipes with mineral, preventing deformation

摘要

Renovating comprises inserting a plastic inner pipe (8) in the old pipe so gap is left between the ID of the old pipe and OD of the inner pipe and pumping filler material into gap through an opening in the old pipe. Pref. the inner pipe is fitted with spacer units (3) prior to inserting into the old pipe. Filler material pumped into place is a mineral with same expansion coefft. as that of the old pipe. It is a hydraulically hardenable material with low deg. of shrinkage and pref. comprises 12 (wt.%) sodium bentonite; 48 oil coated shale dust and oil coated shale cement; 1 concrete flowing agent; and 39 water. ADVANTAGE - Thermal expansion in the inner pipe will not lead to deformation changes at coupling joints.