UV curing for innovative repair

For Clean Water Nashville, it’s important to have the right tools in the toolbox for any conditions discovered in the underground pipes during a rehabilitation project. Cured-in-Place Pipe (CIPP) lining is the primary method used by the program to repair leaking or structurally unsound existing pipelines. Little to no digging is involved in this trenchless process, making for a faster, more cost-effective, environmentally friendly process than traditional pipe replacement. It also minimizes disruption to neighborhoods and businesses. The traditional CIPP lining process consists of inserting a resin-saturated, flexible felt tube inside the damaged pipe. After placement of the liner, the resins are typically activated by using recirculated hot water or steam from a boiler truck. This creates a chemical reaction that converts the flexible felt liner into a rigid, solid pipe that adheres to the interior of the defective host pipe and results in a new pipe within the old pipe. In some situations, the traditional CIPP approach isn’t ideal, for example, when the groundwater is too cold to keep the resin lining from fully curing. In such cases a fiberglass compound liner can be used and hardened by a robotically controlled probe emitting ultraviolet (UV) light. This method was used recently to rehabilitate a broken sewer at Franklin Limestone Road near Mill Creek (Metro Council District 28).