Pipe freeze plugging is a straightforward, cost-effective way to maintain pipes without needing to turn off your systems. The use of liquid carbon dioxide (CO2) allows isolation of the problem in the same line with solid freeze plugs in the fluid in the line. The task can then be carried out without the loss of costly process fluids, system downtime or the need to drain-down and refill. When the work is complete, the plugs can be thawed and the line returns to be fully functioning.