Irrigation systems laid underground must be emptied before winter so that the water in them does not freeze and cause damage. There are different methods for this. Anyone who has not chosen a system with automatic drainage can remove the residual water by blowing it out and blowing the pipes dry.
When blowing out, the water is removed from the water pipes
What is the blowout?
When blowing out, you use a compressor to force compressed air through the irrigation pipes. This pushes the residual water in it upwards and thus ensures that the pipes are free and can no longer freeze. Incidentally, with this method, the actual pressure is less important than the amount of air. Therefore, work with the lowest possible pressure, a maximum of 3.5 bar is sufficient. In addition, when installing the irrigation system, use not only plastic pipes (for which you should prefer flexible polyethylene pipes to rigid PVC pipes anyway), but also metal pipes in between. As the friction of the air generates a great deal of heat when the air is blown out, the metal pipes serve to protect the plastic system.
This is how you proceed when blowing out
When blowing out, it is best to proceed as follows:
- Close the water supply gate valve.
- Connect the compressor 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 that at least one valve is open! Otherwise the compressor must not be switched on. When you are done, the compressor will turn off first, and only then will the controller turn off.
safety instructions
The blow out method is not without risk and can cause serious injury if you do not follow the safety instructions. You should definitely wear safety goggles and stay away from all parts of the irrigation system during use - the pipes running underground, as well as the valves and the exit points should be avoided as far as possible.
tips
This technique is not necessary for above-ground irrigation systems. All you have to do here is shut off the water supply, roll up the garden hoses and store them in a frost-free place.