Vancouver's Pipe Freezing Contractor Tel. 778 321 2653

What you ask us...

How long does the freeze last?

As long as you would like it maintained. Typically freeze plugs on pipe of less than three inch diameter need only to be held for an hour at most, as this is sufficient time to carry out the valve change or tie-in. On larger pipes more time may be needed to carry out the work, and the plug can be held accordingly.

Can the freeze plug withstand high pressure?

Yes. The freeze plug, once formed, will be extremely solid and is actually stronger when under pressure. Tests have been carried out showing that freeze plugs can withstand pressures in excess of 4000 psi. In fact, freeze plugs are used when pressure testing pipelines in order to isolate specific sections.

How long does the freeze plug take to form?

A freeze plug in a half inch copper line will take less than 5 minutes, to form, rising to 1 1/2 - 2 hours for an eight inch diameter steel pipe. These times vary with different pipe materials and contents. Hot water or water containing heating chemicals will take longer depending on the individual circumstances.

Will the pipe be damaged by a freeze plug?

No. The freeze is a controlled process where the ice that is created is very brittle (due to the very cold temperature). This means that the ice cracks and fills with water, re-freezes, cracks and so on, until a plug is created. The freeze plug expands along the length of the pipe and the result is stress free ice.

Does liquid nitrogen damage the pipe?

No. Once the area has been defrosted the pipe returns to its original state. In fact, 'heat-treating' steel with cryogenic refrigerants such as liquid Nitrogen actually increases the material's strength.

What precautions must be taken during a freeze?

The pipe needs to be supported at all times. Hot works need to be carried out a safe distance from the freeze plug. This distance varies according to the type of work and the size and orientation of the pipe.

How long does it take to defrost?

It only takes minutes to defrost a pipe. Our technicians will carry out a controlled defrost so that there is no loose ice left in the system before the circulation or flow is switched back on.