When you have a large commercial, industrial or multi-story living accommodation without sufficient isolating valves around the various circuits, it will typically be impractical to shut off the flow of heating or hot water to the whole building to carry out pipe repairs and alterations.In these instances, it is sensible to use pipe freezing to prevent the flow of heating or hot water while the repairs are being carried out. By leaving the heating or hot water on, the unaffected areas of your building can still receive the services throughout the repair or alteration.
When pipes are repaired by normal methods, the leak is found then the heating/plumbing engineer will find the nearest shutoff valve. In large commercial, industrial and multi-storey living accommodations, the closest shutoff valve may be situated considerable distance away. If that valve is broken, the next nearest shutoff valve will have to be used. In the worst case scenario, the engineer won’t be able to locate the shutoff valves or all of the valves are not operational, which means a large section of the building or the complete building is left with no heating or hot water for a large amount of your time, depending on the severity of the repair.
Once the heating or hot water has been isolated and allowed to cool down, the lines are drained. Then the engineer can cut out the section of pipe and replace it with a new piece of pipe. Once the repair is finished, the repaired section of pipe is tested for leaks. If everything appears to be normal, the pipe repair is successful and the flow of heating or hot water can be resumed.
The Method of Pipe Freezing
There are some instances where the traditional method of pipe repair isn’t possible. This includes the shortage of operational isolating valves and causing an inconvenience to the building’s occupants who may be without heating or hot water for an extended period of time.
When such hurdles like this arise, pipe freezing is the answer. Pipe freezing can be achieved in many ways but for this article, we can use a recent example on a project that we are currently undertaking at Capital Building, Liverpool. The pipe freeze was achieved through the use of liquid nitrogen that was handled by a specialist sub-contractor, the liquid nitrogen is applied using a specialist technique which results in the formation of a solid ice plug within the pipe.
Once the heating or hot water has stopped flowing through the affected pipe, the repair takes place as it normally would. If the ice plug was only used to stop the flow of heating or hot, it will melt after a short period of time and the flow of heating or hot water would automatically be restored to the affected pipes. If a shutoff valve was installed, the heating engineer would simply open the valve to restore heating or hot water and check for additional leaks. Check out the below video which provides a visual demonstration of the above topic.