Does this work? Is it reliable?
Yes! Pipe freezing using cryogenic liquids (such as Liquid Nitrogen) has been carried out successfully around the world for at least the last 40 years. The first pipe freezing company to operate in the UK, for example, was established in the 1970?s and they are still freezing pipes today. Nitro Pipe Freeze offers a safe lockout of pipe systems and our procedures are recognised and approved by WorkSafe BC.
Can you freeze moving water?
No. The water in the system needs to be static before it will freeze. In the case of a heating system, the pump would need to be shut off beforehand. If a valve or pipe is leaking then it is usually possible to freeze it. The leak needs to be stemmed as much as possible before starting to freeze the pipe.
How long does the freeze last?
As long as you would like it maintained. Typically freeze plugs formed in less than three inch diameter pipe, 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.
Why do pipes break when they freeze in winter?
The Canadian weather in winter is renowned for being cold enough to freeze pipes and cause damage to buildings and their contents. The common misconception is that it is the ice that expands and damages the pipe. In fact the ice expands along the pipe which then pushes against the trapped water. The trapped water will not compress (unlike air) and so the pressure in the pipe rises. This continues until the pressure exceeds the pressure rating of the pipe itself, and then the pipe will break. It is in fact water pressure that does the damage and not the ice itself. If a faucet is left dripping, the pipe may still freeze but it will not be damaged as there has been no increase in water pressure due to the dripping tap.
If water in a pipe is frozen in an uncontrolled way (such as exposed pipes in winter) then pockets of unfrozen water may exist leading to a damaging pressure increase. Isolating pipes through liquid nitrogen pipe freezing is a controlled process carried out on a small area of the pipe. If freezing needs to be carried out close to a dead end then appropriate pressure relief measures will be carried out, preventing any potentially damaging spikes in pressure.
Does NITRO PIPE FREEZE™ do plumbing work aswell?
No. NITRO PIPE FREEZE™ is purely a specialist pipe freezing contractor. We work alongside pipe trade professionals to help them to complete jobs in a timely and cost effective manner.
Will the freeze plug let go at high pressure?
No. The freeze plug, once formed, will be extremely solid and is actually stronger when under pressure as the water is denser. We have successfully held back pressures of 200 bar or 3000psi freezing high pressure fire sprinkler lines on large cruise ships.Please see our Marine page for more information. Tests have been carried out showing that freeze plugs can withstand pressures in excess of 10000 psi. In fact, freeze plugs are used when pressure testing pipelines in order to isolate specific sections. In tests, the pipe has been shown to give way before the plug will move when pressure has been increased on one side of a freeze plug formed with Liquid Nitrogen.
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 approximately 3 – 4 hours for a ten inch diameter steel pipe. These times vary with different pipe materials and contents as well as several other factors. 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 pipe 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 pipe freeze plug expands along the length of the pipe and the result is stress free ice.
Are you insured?
Yes. We carry $5 million in general liability insurance. We are registered with Worksafe BC and we are insured to work in all types of buildings including airports, hospitals and industrial plants.
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.
Is Liquid Nitrogen dangerous?
Liquid Nitrogen is extremely safe when handled correctly. It is not flammable and is also non-toxic and completely inert. It is however very cold and can displace the air in a room which would lead to an Oxygen depleted atmosphere. Nitro Pipe Freeze are experts in the safe handling of Liquid Nitrogen and carry out site specific risk assessments on each job. We work to strict method statements and maintain a safe working environment throughout the freezing process. Please contact us on (+1) 778.321.2643 if you have any questions.
What precautions must be taken during a pipe freeze?
The pipe freeze 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.
What size of pipe can you freeze?
NITRO PIPE FREEZE™ can freeze almost any pipe up to 16 inches in diameter and beyond.
How long does it take to defrost?
It only takes minutes to defrost a frozen 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.
What about safety?
We take safety very seriously. Our technicians are highly trained in safe work procedures handling liquid nitrogen. We work to strict method statements and risk assessments that are site and job specific. Please contact us if you would like futher information.
Why not use rental equipment, CO2 kits, or pipe freezing machines?
There are many reasons to go with a pipe freezing contractor. A specialized pipe freezer using liquid nitrogen will freeze pipes faster, as well as freezing large diameter pipes and also chemicals including glycol. This is because Liquid Nitrogen can get down to -196C whereas most other systems can only get down to -40 or -50C at best.
A kit or machine is very limited in what it can safely isolate. Using a dedicated pipe freezing service will produce a better result and contractors can have complete confidence in the freeze plug while carrying out their work.