Level 3 inspections may result in a number of recommendations in how to address a corrosion in metal pipes. Our extensive experience in both inspection and repair means we can find creative, nontraditional solutions to meeting the needs of projects that are limited because of timelines, funding and even size of the pipes.

One such solution came from the need for a nontraditional approach to slip lining. The pipes were large and there were constraints on the project. The client had not been able to find an acceptable answer from other contractors and turned to Glenn Underwater Services, LLC for the answers.

The existing 10′ diameter corrugated metal pipeline (CMP) was used as a storm water collection pond outfall. The pipe carried water from a collection pond in the middle of a coal power generating facility to the river adjacent to the plant.

During the original inspection, our dive team had found significant loss of section along the invert for the first 300′ of the CMP. The traditional HDPE fusion to connect the carrier pipe would not be feasible due to pipe access and the carrier pipe diameter.

Our project team developed a plan to use a bell and spigot type HDPE carrier pipe that would be lowered, transferred and assembled in the pipe without the use of heavy equipment. Our patent pending bulkhead was installed on the outfall end of the pipes to allow divers to enter and otherwise impossible situation. During the entire project the pipe had to remain in operation, and discharge water into the river.

The project was completed in two phases. Phase one consisted of patching and re-supporting the pipe as well as installing a guide system to allow for smooth installation of the new carrier pipe. In Phase two, we installed rigging points, winches, pipe transferring capabilities and finally the pipe and competed the grouting.

By the end of the project, we had undertaken a repair project that involved diving, confined space entry and rescue, boating, barge support, high risk work tasks, specialized cellular grouting, concrete placement and engineering to support the project. The result? The project was completed in the contracted 7-month time frame, within budget, and without recordable injuries.