HG: DRIP Column September 20, 2008
Winterizing backflow-prevention devices important
Taking the time to winterize your backflow-prevention device correctly this fall can save you money next spring.
If you have an irrigation system that is connected to a domestic (treated) water supply, the backflow-prevention device protects clean, potable water from being contaminated.
Correct winterization prevents any damage to the device and to your sprinkler system, which can be costly.
Of course, not everyone has a backflow preventer on their sprinkler system, only homeowners whose systems are connected to the domestic water supply connected to a house.
Backflow is used water that can siphon back into your clean, potable water system from a drop in water pressure.
This can be caused by several things, such as firefighters taking large amounts of water out of the water system to battle a blaze or a water-main break or a repair.
If the water siphoned back into the potable water system is contaminated by weed killer, fertilizer or pesticides that may have previously settled around your sprinkler heads, it can be toxic.
Backflow devices are important to maintaining healthy, safe drinking water for all of those connected to the public drinking water system in your neighborhood.
Following the pointers below and setting up your device according to the graphic will help you achieve a successful winterization of your system.
This will allow your system to operate for many years at minimal cost to you, thus saving you money, and preventing a substantial loss of water due to an ineffective backflow device or system.
1. Shut off water supply to sprinklers (see No. 1).
2. Close valves on each side of device (see No. 2).
3. Do not blow air through device. Attach air compressor to blowout tee, turn first zone on using clock (see No. 3).
4. Apply air to zone until only air is coming out of sprinkler heads and repeat for each zone.
5. Open blowout pipe (No. 4) and attach compressor to blowout tee (No. 5) on supply side. Blow out supply line from device back through blowout pipe. This does not apply if you have a stop and waste valve for the main shut off.
6. Turn both valves on device and all test port valves to 45 degrees for winter (See No. 2 and 6).
Add these steps for a reduced-pressure device only:
7. Loosen all relief-valve cover bolts until water drains out.
8. Do not remove cover.
9. Loosen threaded cap (No. 2) and allow water to drain. Leave loose for winter.
If you have a pressure reducing valve (PRV) on your sprinkler system to regulate the water pressure, and it is located above-ground where it would be prone to freezing, you will also need to winterize it properly. This will prevent damage to the PRV and your system due to a break in the sprinkler system.
If you have any questions or need guidance, please contact your water provider, plumber or backflow tester BEFORE this year’s first freeze.
We live in a semiarid climate where droughts will always be a part of our environment. Water for our future means conserving now. The Drought Response Information Project (DRIP) is a collaboration among the valley’s domestic water utilities and CSU Cooperative Extension to provide information and educate the public about drought and the importance of water conservation.