Irrigation systems installed underground must be drained before winter so that the water in them does not freeze and cause damage. There are various methods for this. If you have not chosen a system with automatic emptying, you can remove the remaining water by blowing it out and thus blow the pipes dry.
How does blowing out irrigation systems work?
When blowing out irrigation systems, compressed air (maximum 3.5 bar) is forced through the pipes using a compressor to remove residual water and prevent freezing in winter. Each station is blown out until no more water comes out. Safety glasses and a distance from the system components are important.
What is blowing out?
When blowing out, you use a compressor to force compressed air through the irrigation pipes. This pushes any remaining water upwards and ensures that the pipes are free and can no longer freeze. By the way, with this method it's less about the actual pressure than the amount of air. Therefore, work with the lowest possible pressure, a maximum of 3.5 bar is completely sufficient. In addition, when installing the irrigation system, use not only plastic pipes (for which you should give preference to flexible polyethylene pipes over rigid PVC pipes anyway), but also metal pipes in between. Since the friction of the air creates a lot of heat when blowing out, the metal pipes serve to protect the plastic system.
How to blow out
When blowing out, it is best to proceed as follows:
- Close the water supply gate valve.
- Connect the compressor (€69.00 on Amazon) to the compressed air connection of the irrigation system.
- There is a pressure regulating valve on the compressor. Set this to 3.5 bar (or less).
- Turn on the compressor.
- Blow out each station until no more water comes out.
Make sure at least one valve is open! Otherwise the compressor must not be switched on. When you are finished, the compressor is switched off first and then the control unit.
Safety instructions
The blow-out method is not safe and can cause serious injury if you do not follow the safety instructions. You should definitely wear safety goggles and stay away from all components of the irrigation system during use - both the underground pipes, the valves and the exit points should be avoided as much as possible.
Tip
This technique is not necessary for above-ground irrigation systems. Here all you have to do is turn off the water supply, roll up the garden hoses and store them in a frost-proof place.
