SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/43432
opening the drain valve for each zone and the main line. Once the valves have emp- tied, the manual drains must then be closed. The backflow devices and irriga- tion controllers also need to be winterized. With either of the systems, it is impor- tant to activate each valve to drain water out of the valve and allow air to enter into the system to slowly push water toward the drains. BACKFLOW WINTERIZATION There are several types of backflow de- vices or assemblies used in irrigation sys- tems that are connected to potable water systems. The most common is a pressure vacuum breaker. In order to winterize this device, open the top of the pressure vac- uum breaker and remove the internal discs and springs. Storing these components near the irrigation controller makes them easier to find come springtime. Turn the handles on the two ball valves and all test ports to a partially open 45 degree position. Ball valves, when fully closed or fully open, will trap water in between the ball and the valve housing. The valve housing will crack dur- ing a freeze if not left partially open. Some newer pressure vacuum breakers are freeze resistant, with a built-in relief valve to protect the internal components and the body from freezing. It is not nec- essary to remove the internal components in these devices. The other types of backflow assemblies used in irrigation systems are a reduced pressure principle backflow device, or RPZ or in some areas a double check valve is permitted for use on irrigation sys- tems. In either case, it is usually best to re- move this device completely during the winter and store indoors. Then cap the pipes to the irrigation system. If removal of the backflow device is not possible, carefully follow the manufacturer's in- structions for winterization. Each manu- facturer has specific instructions for winterizing. IRRIGATION CONTROLLER AND RAIN SENSOR WINTERIZATION To prepare the irrigation controller for winter, simply turn the controller to the www.stma.org "off" or "rain shutdown" position. You can also disconnect the power and remove the battery, but this is not necessary. It is important not to allow the controller to cycle through an irrigation schedule with- out water in the system because the re- mote control valves require water to move through the solenoid assembly for cooling purposes. If your irrigation system is equipped with a rain sensor or a soil moisture sen- sor, it is not usually necessary to cover or remove the sensor for the winter. Check with the manufacturer to make sure the sensor does not require any special in- structions for winterization. PUMP WINTERIZATION Centrifugal pumps have a drain valve located at the base of the pump housing that needs to be removed and stored for the winter. The power supply for the pump should also be disconnected to prevent the pump from being accidentally turned on without any water, as a pump running without water will quickly burn up. Addi- tionally, if the pump is drawing water from a lake or stream, the intake hose has a foot valve located at the base of the suction line. It is necessary to completely remove the in- take or suction line from the water and store it for the winter. Sometimes a check valve is also located on the discharge side of the pump, which also needs to be removed and stored for the winter. Any part of the pumping system that can be exposed to freezing conditions will need to have the water drained to prevent damage. Often there are drain plugs or valves meant to be opened to facilitate drainage. Preparing an irrigation system for win- ter can be a complicated process. An im- properly winterized irrigation system can be an expensive repair the following sea- son. Save time and money next year by in- vesting in proper winterization of the irrigation system now. ■ Tom Barrett is the owner of Green Water Infrastructure, a consulting company that integrates water resources for sustainable site development. He can be reached at tom.barrett@thinkgwi.com. SportsTurf 31