The HFT® Pipestoppers® Qwik-Freezer™ Pipe Freezing Equipment uses liquid carbon dioxide (CO2) to freeze stationary liquid in any chosen sections of pipe or tubing. By producing very low 'dry ice' temperatures, Qwik- Freezer™ forms a secure in-line ice plug. The ice plug temporarily isolates the liquid in the system and allows repairs or modification to be made without draining or shutting off systems.