Frequently asked questions

When a pipe is to be frozen, a cryogenic box is specially built around the pipe, which must be perfectly sealed. Liquid nitrogen at -196° is introduced into the cryogenic chamber until the pipe is covered with nitrogen. The pipe must be immersed continuously in nitrogen until the cryogenic plug is created – this can require from a few dozen to several hundred liters of nitrogen.

Ice always expands along the path of least resistance, since only part of the pipe is frozen. The cryogenic plug can expand into the pipe on either side of the cryogenic chamber.

This depends largely on the liquid in the pipe and its temperature. Processes can take from 30 minutes to 10 hours.

The cryogenic plug is kept constantly immersed in nitrogen until the repair is complete. To do this, you need to let us know how long your technical intervention will take, so that we can keep a sufficient stock of nitrogen.

Our extensive experience in cryogenic closures and mathematical calculations that take into account pipe diameter, the nature of the liquid and its temperature are used to assess freezing times.

While the pipe is frozen it becomes brittle due to the extreme low temperature, but when it returns to its initial temperature it regains its properties.

To change a valve, you’ll need a cryogenic plug on both the upstream and downstream ends, just as you would when installing a tee.

• Cast iron & ductile iron
• Carbon steel & stainless steel
• Copper
• Aluminum
• Brass
• Consult us for specific materials (PVC, polymer, etc.)