Untitled - Future Pipe Industries

8.0: Repair and replacement of pipe
The flow in the pipe section should be stopped by closing the appropriate valves in the system, or plugging the pipe ends
and then draining the line.
The replacement of a pipe or a fitting is similar to that of a closure (i.e., laying of the last length of pipe or fitting which closes
or completes the line or a section of the line).
To completely replace a damaged pipe, the couplings are first carefully removed by cutting them off with a circular blade
saw. The pipe, and the rubber rings from the pipes adjacent to it, is then removed from its location in the line. Insert the new
pipe as indicated below:
• Carefully measure the gap where the replacement piece has to be fitted. The replacement piece must be well centered, and
an equal clearance of 3/4” must be left between the inserted pipe and the adjacent ones.
• Use a pipe on site with a constant OD, if necessary cut the pipe with a circular saw square to the end and bevel
the pipe end with a grinding disk.
• Pull the coupling into the pipe ends of the new pipe after abundantly lubricating the ends and the sealing rings. It will be
necessary to gently help the second sealing ring over the chamfered (beveled) end of the pipe.
• After cleaning them thoroughly, lubricate the ends of the two adjacent pipes well.
• Insert the pipe in its final position and pull the coupling over the adjacent pipes up to the home line with the mechanical
equipment described in section 5.2.
To replace a damage pipe section
• Carefully measure the gap where the replacement piece has to be fitted. The replacement piece must be 1 1/2” shorter
than the length of the gap. The damaged section should be cut using a circular saw (taking care of electrical hazards when
working in a wet trench).
• Use a pipe on site with a constant OD, cut the pipe with a circular saw square to the end, to the required length and bevel
the pipe end with a grinding disk. The new pipe section must be well centered, and an equal clearance of 3/4” must be
left between the inserted pipe and the existing ones.
• Pull the coupling into the pipe ends of the new pipe after abundantly lubricating the ends and the sealing rings. It will be
necessary to gently help the second sealing ring over the chamfered (beveled) end of the pipe. After cleaning them thoroughly,
lubricate the ends of the two adjacent pipes well.
• Insert the pipe in its final position and pull the coupling over the adjacent pipes up to the home line with the mechanical
equipment described in section 5.2.
• Alternatively for sizes 16 through 64”, two standard ductile iron mechanical couplings may be used to join the new pipe
sections. Care must be taken not to over-tighten the mechanical coupling bolts. Tighten enough to seal the joint and no more.
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