Prime-Flex polyurethane grouts are designed for manhole, sewer pipe, and lateral grouting .
Some grouts cure to a solid foam, while others to a flexible gel.
Hydrophilic grouts are used to stop leaks through cracks and joints in undeground structures, while Hydrophobic grouts are typically used to fill voids and stabilize soils . . NSF Standard 61 Drinking Water System Components - Health Effects. Rockaway Industrial Blvd.