Your liner is done. Installation and curing went off without a hitch. The only thing standing between you and the completion of the project is to reinstate the branch fittings that were lined over. And while you have the tools and equipment to open those branch lines efficiently, if there are hardened resin slugs, or uncured resin wash behind the liner, what should be just another step in the process can quickly turn into a time-consuming nightmare.
Whether you are using a robotic or mechanical device – from inside the lined pipe or from the backside – hardened resin slugs can be difficult to cut through. In larger pipes, like manhole-to-manhole mainline work, the branch lines are bigger, allowing the resin to migrate into the pipe with less risk of filling the branch. Yes, it happens in big pipes, but in smaller diameter applications the risk is much higher. Because the branch lines are smaller, the space available for the resin to migrate and harden is smaller. Using a complete system backed by a manufacturer (installation method, resin and liner designed to work together) combined with curing at the right temperate for the correct amount of time will often mitigate this issue. If you continue to experience resin slugs with the right methods and materials, the most effective means of controlling them is to pre-line the pipe. This will encapsulate the resin between the outside of the liner and pre-liner, inhibiting its ability to migrate.
Pre-lining also works well with UV/LED curing systems, where the problem isn’t hardened slugs, but uncured resin caused by migration beyond where the light can reach. By encapsulating the resin, the light is able to penetrate and cure the resin, instead of it becoming uncured resin wash that makes opening branch fittings difficult.
James Kicklighter is a Technical Services Manager with MaxLiner