Winterizing Your Farm Irrigation System - A Handy Checklist
The Purpose of Winterizing Farm Irrigation Systems
You may be done with harvesting the crops this season, but it’s not time to rest just yet. Left unprotected, your irrigation equipment will remain exposed to the risk of damage by the ice that forms within it. If your system is not blown out properly, you might end up with cracked or burst pipes, malfunctioning irrigation equipment and costly repair bills. As the temperature begins to drop, it’s time to protect your commercial irrigation system. This one final seasonal project will ensure that your equipment will be ready to serve you again in the spring.
Whether you have a farm, fruit orchard, or vineyard, the same irrigation winterizing principles apply; you must remove excess water to prevent damage caused by ice. The blow-out method forces high-pressure air through all the pipes and equipment to remove remaining water. While similar to the steps required for winterizing a commercial or landscape irrigation system [insert link to previous blog here], there are additional components to an agricultural irrigation system that require attention. Blowing out this equipment requires a large-capacity air compressor. We recommend a 25-50 HP diesel compressor with 185 CFM and 175 max PSI.
Below is a checklist of agricultural irrigation equipment that will require winterizing maintenance.
Agricultural Equipment Requiring Attention
Travellers
To winterize a hard hose traveller irrigation system, you must remove water from both the pipe and the turbine. To accomplish this, connect the compressor to the pipe inlet, open the other end, and blow out the water with the compressor. Next, remove the drain plug or open the valve on the turbine to drain out all the water, and then leave the plug out or valve open until the next use in the spring. Lastly, remove the battery and store it indoors over the winter.
It is also useful to perform a 15-point inspection to look at all the different points where the traveller could wear. This will help identify any critical maintenance issues that require attention before the busy season.
Pumps
To winterize a pump, remove the drain plug or open the drain valve to remove all the water. Next, it’s time to replace the plug, and an optional step is to add antifreeze. Aboveground pumps are notorious for retaining water in the casing, so removing the water will keep it from accumulating and freezing in the bottom of the case. Lastly, it is critical to cover both the inlet and the outlet to prevent animal entry and burrowing.
Filters
To winterize irrigation filters, disconnect the inlet and outlet lines to allow excess water to drain. Be mindful to remove secondary filters and drain them separately as well. This is a good time to check the screens to determine if they are still in functional condition, and to clean them of sediment. You may reassemble or remove the case and screen for the winter. If removed, take care that as with other components of the system, you close all openings just enough to allow excess water to escape, but not enough to allow animal entry.
Underground Systems
As with commercial irrigation systems, underground pipe systems require a blow-out to remove remaining water. First, disconnect the pump from the underground pipe and close any open vents. Next, connect the compressor and blow water toward the pump end of the system until it appears that all water is out. If multiple branches of underground pipe exist, each one must be isolated and blown out separately. You’ve already shut down your water supply, so be sure to shut down any linked timers and controllers. Lastly, ensure that you cover all openings to prevent animal entry.
Based on years of experience, we highly recommend that you remove control valves and store them in a dry location where they will have the required protection against freezing. Once removed, ensure that you cover the resulting openings to block critter entry. However, if the valves are not removable, you must drain them properly to remove any remaining water. Valve draining will prevent them from freezing and cracking when the temperatures dip below the freezing point.
Solenoid valves typically have a manual bleed lever consisting of a thumb type screw that turns easily to drain. Gate valves trap water in the bonnet, and ball valves trap water inside the ball itself. The telltale sign of a ruptured ball valve is a burst side, whereas a ruptured gate valve will either split its bonnet or packing nut or show a hairline crack running down its side. After you drain the valves, allow the drain port to remain open.
Ginseng Gardens
Essentially an above ground sprinkler system, ginseng garden irrigation systems require similar attention. To drain a ginseng garden sprinkler, open the flush valve at the terminal end of the main header, and close off all lateral branches. Connect the compressor to the main header and blow out all remaining water. Next, close the flush valve, and open all lateral valves individually, blowing them out one at a time. Once you have completely flushed all valves, open them just enough to allow any accumulated water to escape, but not enough to let small animals find their way inside.
Drip Irrigation Systems
The same principles that apply to other forms of irrigation systems also apply to a drip irrigation system. Essentially, the goal is to disconnect the water supply to your system and remove all the remaining water from the backflow device, filters, valves, and all branches of the drip line. We have seen that some landscapers prefer to install automatic drain valves near the lowest region of the system to guarantee that remaining water will drain out. Lift layflat or poly pipe hose several feet at a time, ensuring that remaining water drains out of each section. Once you have drained each section of poly pipe and layflat hose and its corresponding micro tubing and connectors, be sure to close up the ends of the hoses. Finally, to roll up the hoses, you can do it manually or via automation onto a spool.
The Water Is All Drained. Now What?
The hard part is done - you’ve drained your travellers, pumps, filters, underground pipe systems, control valves, drip system, and aboveground ginseng sprinklers. However, winterizing goes hand-in-hand with routine maintenance and equipment storage. What’s next on the winterizing checklist?
Service Worn Parts
Service any parts that have suffered wear-and-tear during the growing season. Gearboxes, motors, drive lines all deserve an inspection. Be sure to check the service engine that drives the pump and change the oil to ensure it will be ready for next spring.
Restore the ground around your moveable equipment
Now is the time to repair rutted tracks from travellers or pivot wheels. Repairing these tracks as part of the winterizing regimen will help prevent erosion prior to the next growing season.
Test metering equipment
The flow meter at the pump represents one of the points within an irrigation system that is susceptible to damage from the winterization process. A functional flow meter is critical to ensuring proper pump volumes, and a damaged flow meter will result in inaccurate future water flow readings. Take note of the end reading on your flow meter, such that you will have an accurate record of water consumption over the course of the growing season.
Secure Electrical Components
Lock electrical boxes to avoid accidental starting of irrigation components. If the system were to be unintentionally turned on, water could potentially be introduced, consequently, freezing and cracking the very components you’ve worked so hard to protect.
Equipment Storage
Now that you’ve drained all your equipment, take the final step to store it properly. Your expensive irrigation tools are one of your biggest investments; don’t leave them out in the cold. Whenever possible, bring in your large, moveable pieces of equipment to provide them with shelter from the ice, wind, and snow. Exposure to the elements will reduce longevity of your equipment. Keep in mind that local wildlife will also be looking for safe shelter, so take precaution to protect your equipment from burrowing pests.
Insulation and Protection
For equipment facing exposure to the elements and not mobile, make sure you provide proper insulation. An exposed central shut-off valve, irrigation pump foot valve, backflow preventer, or above-ground pipes will be subject to damage without protection. Plastic or self-sticking foam insulation tape works well to keep moisture out of these critical components of your system. Be mindful, however, to prevent blocking drainage vents or air outlets with your insulation.
To summarize, it is critical to remove excess water from agricultural irrigation systems and equipment to prevent damage brought on by freezing water. Furthermore, after the harvest but before the first freeze is the perfect opportunity to perform preventive maintenance on all your equipment. Finally, proper storage and protection of your equipment will go a long way to ensure the longevity of your irrigation equipment.
Do you have questions regarding winterizing your farm irrigation equipment? Our irrigation experts are just a phone call away! Alternatively, head to your nearest Vanden Bussche location or contact us online, and one of our irrigation experts will be in touch with you soon.