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Getting Your Yard Sprinklers Ready for Winter!

Last Updated on Saturday, 15 May 2010 08:57 Friday, 07 May 2010 17:00

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Articles - Irrigation Systems

Sprinkler_HeadTo start the "blow out," shut off the irrigation water supply and with the compressor valve in the closed position, attach the air compressor hose to the fitting. Activate the station on the controller that is the zone or sprinklers highest in elevation and the furthest from the compressor. Close the backflow isolation valves. It’s a good idea to wear a pair of safety glasses before using the compressed air. Then slowly open the valve on the compressor. This should gradually introduce air into the irrigation system. The blow out pressure should remain below the maximum operating pressure specification of the lowest pressure rated component on that zone and should NEVER exceed 80 PSI.

Each station/zone should be activated starting from the furthest station/zone from the compressor slowly working your way to the closest station/zone to the compressor. Each station/zone should be activated until no water can be seen exiting the heads, this should take approximately two minutes or more per station/zone. It is better to use two or three short cycles per station/zone than to have one long cycle. Once the station/zone is dry, you should not continue to blow air through the pipe. Compressed air moving through dry pipes can cause friction, which will create heat and the heat could cause damage.

Once the water has been removed from the irrigation system, disconnect the air compressor and release any air pressure that may be present. If your backflow device, the most common backflow installed is called a Pressure Vacuum Breaker, has ball valves, open and close the isolation valves on the backflow device numerous times to ensure that any trapped water has escaped from the upper areas. Leave the isolation valves open at a 45° angle (approximately 1/2 open) and open the test cocks.

If you have outdoor mounted controllers, leave the power on and the dial/switch in the "OFF" position. The heat from the transformer will keep the enclosure warm enough to prevent condensation from forming inside the controller enclosure. The dial in the "OFF" will keep the controller from activating the solenoids in the field.

If you have indoor mounted controllers, you may either leave the power on and the dial/switch in the "OFF" position OR you may remove the battery backup and unplug the transformer.

If you have rain sensors, there is not much to do to prepare the rain sensor for the winter months. If your sensor is the type with a cup or bowl that catches water,  remove the water and place a plastic bag over the sensor. This will keep any water from accumulating and freezing in the cup or bowl area. If your sensor is the type that uses wafers or discs, remove the wafers and store them in the garage for the winter months. This will keep damp wafers from freezing.

WARNING! WEAR ANSI APPROVED SAFETY EYE PROTECTION! Extreme care must always be taken when blowing out the system with compressed air. Compressed air can cause serious injury, including serious eye injury, from flying debris. Always wear eye protection and do not stand over any irrigation components (pipes, sprinklers and valves) during air blow out. SERIOUS PERSONAL INJURY MAY RESULT IF YOU DO NOT PROCEED AS RECOMMENDED!

  • Do not allow the air pressure to exceed 80 PSI for systems with PVC piping and 50 PSI for systems with polyethylene piping.
  • Do not stand over component parts while the system is pressurized with air.
  • Do not leave the air compressor unattended.
  • Do not blow the system out through a backflow or pump. First blow out the system, then drain the backflow or pump.
  • Do not leave the manual drain valves open after the blow out.
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