As fall mornings chill the air and maple leaves turn to gold and crimson, it becomes time to alert your clients to the benefits of winterizing their irrigation systems.
By scheduling a winterizing program, you will ensure the life of the watering system and head off any potential start-up problems in the spring. Winterizing is accomplished by properly draining the system before the onset of frost and snow in order to prevent the expansion of water left in the system and the subsequent cracking of irrigation lines.
Here are several tips to preparing a system for winter, depending on the type of irrigation installed:
DRAINING A SYSTEM MANUALLY. Many commercial and residential systems utilize manual drain valves for winterizing. This will consist of one or more manual drains on the main line and several automatic drains on the lateral lines.
1) Shut off the water supply to the system.
2) Open the manual drains on the main line and leave them open,
3) Open the drain valve located near the water supply, and have a pail handy.
4) Open the small drain valves (pet-cocks) on the backflow preventer and leave them open.
5) Make sure the shut-off valve is working properly and no water is leading back into the system. If it is sealed correctly, close the drain valve by the water supply when it has finished draining.
6) If you have an automatic controller, allow it to go though a cycle with the system drained. This allows all the valves to open.
7) If you have a manually-controlled system, open all zone valves and leave them open.
BLOWING OUT A SYSTEM. Large systems installed with PVC pipe, or systems with ground conditions, can make it impossible to use gravity drainage (manual drain type). That¹s why blowing out a system is recommended. This requires the use of an air compressor, which builds up enough pressure and volume to force all the water out of the lines.
1) Turn off the water supply.
2) Attach the air compressor to the proper fitting on the system.
3) Turn on the compressor and go to the controller or the manual z valves and open each individually. Let it run until all the water has been blown-out of each station.
4) Open the drains (pet-cocks) on the backflow preventer and leave them open.
5) Open the drain at the water supply until the water stops flowing.
6) If you have an automatic controller, allow it to go through a cycle with the system drained. This allows all the valves to open.
7) Never exceed 60 psi at the air compressor. Excessive pressure will void sprinkler manufacturer warranties and will cause premature sprinkler failure.
Note: If the backflow device has a ball variation, be sure to turn the handle 45 degrees across the body of the valve.
When it¹s time to restart the system in the spring, the lines will be clear and ready to go to work!
The author is senior vice president, irrigation and lighting operations, John Deere Landscapes.