Top 8 Tips for Winterizing Your Golf Course Irrigation System
Winterization is the process of eliminating all water from an irrigation system to prevent the potential damage of any of its components. In cold climates where freezing is inevitable, winterizing is critical. Water expands in volume approximately 9% as it transitions from liquid to solid, resulting in ruptured equipment within a closed system. However, with proper winterizing of your golf course irrigation system, you’ll be able to relax and keep warm over the cold months, knowing your equipment will be prepared to perform again in the spring. The time invested now in winterizing your system will pay off dividends when you next need it.
Preparing to winterize a golf course irrigation system can feel overwhelming; the system covers a broad area, and there are many components requiring attention. Furthermore, an average golf course network of pipes can hold 22,000 to 27,000 gallons of water - a significant volume to drain! Golf course operators and commercial landscape contractors are accustomed to irrigation maintenance, however, and winterization is one vital component of that routine. You can easily develop a winterization procedure by utilizing the 8 tips itemized below.
1. Develop a Plan
Having a written winterization plan may feel cumbersome at first, but it will immensely simplify the process next year. Add notes along the way as to what worked and what didn’t and modify it annually. Keep a map of the golf course handy, such that the topography of the course and its corresponding irrigation system are highly visible. Begin your planning in as much advance of the first freeze as possible; air temperature needs to be above freezing when clearing the pipes.
2. Do Your Prep Work
An irrigation system as large and intricate as a golf course system requires the blow-out method of winterizing. This method involves blowing high-pressure air throughout the pipes to force out remaining water.
In the days leading up to your drainage blow-out, flag the position of couplers, drains, and isolation or vacuum valves.
Upkeep growth and maintenance around the sprinkler heads and valves so they are easier to locate on blow-out day.
Identify the location where you might connect a compressor to the network. Ideally, this will be a high elevation in an accessible location.
Two days prior to winterizing, open drains using compressed air. Be sure vacuum valves are operational. Mount quick coupler keys to permit air to circulate into the system. Quick couplers or air vacuum valves are critical to equalizing pressure between the internal environment of the pipe and the atmosphere. These valves allow air to circulate back into the system to promote draining of the irrigation system. They further assist with keeping soil and other debris from suctioning back into the pipe.
Stock up on special fittings for your system. Ensure you have bull hose fittings for 2-inch air compressor lines.
Be sure you have enough fuel to fill your compressor. Furthermore, locate your surplus fuel near where you plan to operate your compressor, to ensure a seamless refuel should you run out in the middle of a blow-out.
Book your air compressor rental early! Compressors are often in short supply during winterization season, and you don’t want to end up with one that is inadequate.
3. Select the Right Air Compressor
Air compressor selection and parameters are key to a successful blow-out of your irrigation system. Understanding their settings can be confusing, however. CFM refers to cubic feet per minute. This is the volume of air that the compressor can push. Typically, you should have twice as much CFM as the flow rate (gallons per minute, or GPM) of the irrigation system. In theory, you could blow out a system with a compressor less than double the GPM, but this would take an unrealistic amount of time, and would result in diminishing returns. Air volume, rather than air pressure, is the critical element with a successful blow-out. Inadequate air volume will allow air to just blow over the surface of the water. Alternatively, excessive air volume will promote heat build up, and can result in damage.
Compressors fall into categories such as 30, 70, 130, or 185 CFM. How do you know which one you need? Typically, compressor size choice is based on system capacity; if the mainline is lengthy, golf course operators and contractors will need to rent a big compressor. This will sustain a large volume of air through the pipes to carry the water through the entire system. For example, if the pump station typically runs at 800 GPM, it is best to rent a 900 CFM or 1600 CFM compressor. It is feasible to pair two compressors if need be, but it is not the most ideal situation. For example, two 450 CFM compressors working together can achieve 900 total CFM. Size is critical, and bigger is better! However, availability is often the driving factor in compressor selection, so see our previous note about booking your compressor rental early.
4. Know Your Way Around an Air Compressor
Your safety and the safety of your system are paramount. To mitigate any potential damage from excessive air, use a long hose connection to dissipate heat; utilize a 2-inch minimum connection; connect into steel piping (PVC fittings will melt); and use a pressure regulator. The pressure regulator should be set at factory recommended pressure (typically 40-60 psi). The pressure regulator should be equipped with an adjustable pressure relief valve, a flow regulating control valve, pressure gauges, and an air and oil separator.
5. Set up for the Blow-Out Procedure
Assigning roles: Ideally, assemble a team of 3-5 crew members to perform the blow-out. One person will be stationed to monitor the compressor. Two to four people will need to be on hand to activate the sprinklers. Each person needs to be equipped with a pressure gauge to also enable pressure checks at quick coupler locations, and to report back to the compressor crew to make adjustments as needed.
Pressure Guidelines: The pressure gauges on the irrigation system will provide different, lower readings than the gauge on the compressor itself. The crew should try and coordinate a steady reading of actual system pressure. Chattering pressure can cause unnecessary damage to the system. Keeping an outlet or valve open will help to manage system pressure. Maintain pressure below 60 PSI for the best results. While water is relatively difficult to compress, air is quite compressible, and can reach dangerous pressures exceeding 600 PSI, which can lead to equipment rupture. Ensure that crew always stands clear of pressurized valves and sprinklers in case of pressure buildup.
Connection: Avoid blowing air backwards through a pump or backflow prevention device. Discharge isolation valves must remain closed. Use a 2-inch or larger steel connection to a mainline pipe.
Elevation: Utilize your topography map and connect the compressor at the highest point on the golf course.
6. Control the Blow-Out Procedure
Initiate the blow-out procedure by prioritizing the highest elevation irrigation zones, as this reduces the risk of water returning to these zones. Likewise, prioritize zones that are the most distant from the compressor, and work your way back sequentially toward the compressor. Continue to monitor pressure within the lines that you are actively blowing out. Blow out each zone in multiple short cycles of 2-3 minutes, as opposed to fewer but longer cycles. Water may settle within little pockets in the system, so the multiple cycles serve to create turbulence to loosen the trapped water.
7. Finish the Blow-Out
How do you know when your lines are clear? Once the output from the sprinklers appears as a fog, you’ll know you’ve got that section clear, and the system should be safe for the winter. Prior to packing up, however, be sure that each sprinkler head on the golf course is blown out. Once you are confident that all zones are clear, close down the valves of each zone. Next, shut down the compressor by slowly closing the flow control valve until air stops flowing. Allow low elevation drain valves to stay open overnight to enable water to drain. Once all pressure is relieved from the system, it is safe to disconnect the compressor.
8. Double Check Your Work
Although it might feel like a redundant task, the following day will serve as an opportunity to check your work and clear any final water that may have escaped the initial blow-out. The average golf course irrigation system will take 2-3 days to appropriately winterize. On Day 2, re-open any valves that were closed, and repeat the same process as the previous day. You may be surprised to see water emerging from zones that previously appeared dry. However, it is likely that each zone will require fewer cycles on Day 2. At the completion of this day, close all the open drain valves, and open all the air relief valves.
Do you have questions about winterizing your golf course irrigation system? Our team at Vanden Bussche has got you covered. Put our golf course irrigation system design and installation experience to work for you.