Understanding the Backflow Preventer
The Role of a Backflow Preventer
The crisp air of autumn heralds the coming of winter, and for homeowners with irrigation systems, this time of year signals one crucial task: winterization. Proper winterization safeguards your sprinkler system against the destructive forces of freezing temperatures. However, even with the best intentions, problems can arise. One of the most frustrating and potentially damaging issues is air coming out of backflow when winterizing. This article delves into the causes behind this common problem, offering practical solutions and preventative measures to protect your irrigation system and ensure its longevity.
The heart of your irrigation system’s protection against water contamination is the backflow preventer. This essential component, often located near the water supply connection, acts as a safeguard against potentially harmful pollutants from backflowing into your potable water supply. Understanding the role of the backflow preventer is crucial to understanding why air coming out of backflow is a concern during winterization.
A backflow preventer essentially functions as a one-way valve. It allows water to flow in only one direction – from the water source to your sprinkler system. Inside, there are typically check valves that automatically close if the water pressure in the irrigation system drops below the pressure in the water supply, preventing water from flowing back towards your house or the municipal water system.
Types of Backflow Preventers
Several different types of backflow preventers are available, each with its specific design and features. These include:
Reduced Pressure Zone (RPZ) Backflow Preventers: These are considered the most robust and provide the highest level of protection. They have two check valves and a relief valve that opens if pressure drops below a certain level, discharging any contaminated water.
Double Check Valve Assemblies: These feature two check valves in series, offering excellent protection.
Pressure Vacuum Breakers (PVB): Commonly used in residential settings, PVBs are designed for systems that do not experience continuous pressure.
Maintenance Importance
Regular maintenance and inspection of your backflow preventer are paramount. This component, like all mechanical devices, is subject to wear and tear. Regular inspections by a qualified professional can help identify and address any problems before they escalate, ensuring your system functions correctly and protects your water supply. Neglecting maintenance can lead to various issues, including leaks, reduced water flow, and, of course, the frustrating problem of air coming out of the backflow during winterization.
Why Air Escapes During Winterization
Incomplete Drainage
So, why does air come out of backflow when you’re winterizing your irrigation system? Several factors can contribute to this problem, and identifying the root cause is the key to resolving it.
One of the primary reasons for air coming out of backflow is incomplete drainage within the system. Irrigation systems consist of a network of pipes, sprinkler heads, and valves. When you winterize, the goal is to remove all the water from these components before freezing temperatures arrive. If water remains trapped, it will freeze, expand, and potentially cause significant damage. Trapped water within the backflow preventer itself can cause it to crack and release air, or to cause its internal components to fail during the winter.
Improper Procedures
Improper winterization procedures are another frequent culprit. The air blowout method is commonly used to remove water from irrigation systems. This method involves using an air compressor to force water out of the system’s components. Many mistakes can disrupt the process:
Not opening all drain valves fully: Many irrigation systems have manual drain valves at low points to facilitate water removal. Failing to open these valves will leave pockets of water in the system.
Insufficient air pressure: Using too little air pressure may not be powerful enough to push all the water out of the system.
Excessive air pressure: Conversely, using too much air pressure can damage the sprinkler heads, pipes, and even the backflow preventer itself.
Neglecting other components: Winterization is not just about blowing out the main lines; you must also winterize sprinkler heads, valves, and any other components that hold water.
Backflow Preventer Issues
Furthermore, problems originating from the backflow preventer itself can lead to this unwelcome issue. The backflow preventer contains intricate internal components, which can malfunction due to age, wear, or damage.
Faulty check valves: The check valves within the backflow preventer are critical to its operation. If these valves fail to seal properly, air can escape during the winterization process.
Debris or mineral buildup: Over time, sediment and mineral deposits can accumulate within the backflow preventer, interfering with the proper functioning of the check valves and other internal components.
Damage from previous freezing events: A backflow preventer that has suffered damage from freezing in a previous winter may be more prone to leaks.
Aging: Over time, components within the backflow preventer can deteriorate, making it less effective.
Step-by-Step Solutions and Troubleshooting
Preparing for Winterization
Fortunately, resolving the problem of air coming out of backflow is achievable with the right approach. The following steps will guide you through the process.
The first step in successful winterization is preparation. Before you even consider connecting your air compressor, take these actions:
Turn off the water supply to your irrigation system at the main shut-off valve. This valve is usually located near the water meter.
Locate and close the shut-off valve leading directly to your irrigation system. This step will prevent any water from the main supply line from entering your irrigation system.
Attach the air compressor. Make sure you use a low-pressure setting on the compressor to avoid potential damage.
The Air Blowout Method
The most common method for winterizing an irrigation system is the air blowout method. Here’s a step-by-step guide:
Connect the air compressor to the designated air inlet valve, typically located downstream from the backflow preventer.
Open all the manual drain valves within the system, if present. This will help water drain from the system, and make it easier to clear the lines with air.
Gradually introduce air pressure to the system. Begin with a low pressure (e.g., 30-40 PSI) and monitor the pressure gauge carefully. Never exceed the manufacturer’s recommended PSI rating for your system components. Over-pressurizing the system can cause severe damage.
One zone at a time, open the sprinkler heads. As you open each zone, you should see water and air escaping. Continue opening each zone until air is flowing freely from all sprinkler heads within that zone, indicating that water has been cleared. Close each zone once you are sure water has been removed.
Repeat steps for other zones, working methodically and allowing sufficient time for the water to be expelled.
Troubleshooting Air Leaks
If you encounter air coming out of backflow during this process, you’ll need to troubleshoot the issue. Several tactics can assist you:
Check all connections: Inspect all connections at the backflow preventer for leaks. Tighten any loose fittings.
Inspect the check valves: The internal check valves are the most common source of problems. If they are not sealing properly, air will escape. Try opening and closing the test cocks on the backflow device to flush the valve. This could help to clear away small debris.
Consider professional inspection: If your troubleshooting steps don’t resolve the issue, consider having a qualified irrigation professional inspect the backflow preventer. Internal problems might be more difficult to detect.
Check for cracks: Look over the backflow body for any sign of visible cracking.
Prevention and Maintenance
Regular Inspection and Maintenance
Preventive measures are crucial to maintaining a healthy irrigation system, which can minimize issues like air leaks during winterization. Regular attention will go a long way.
Regular inspections and maintenance are essential. Develop a habit of doing the following:
Annual system inspections: Schedule an annual inspection of your entire irrigation system. A qualified professional can identify and correct any potential problems before they lead to more significant issues.
Backflow preventer testing: Many municipalities require annual backflow preventer testing. This is best left to a professional.
Leak detection: Throughout the year, periodically check for leaks in your system. Early detection can prevent water waste and prevent water damage to your backflow preventer and other components.
Addressing Problems Promptly
Addressing problems promptly is key. Don’t delay addressing a leaking sprinkler head or a malfunctioning valve. Prompt repairs can prevent small problems from turning into larger, more expensive issues. Furthermore, cleaning and maintaining the backflow preventer is important. Keep the backflow preventer free of debris. This helps ensure it performs its function effectively and does not cause issues such as the leakage of air.
When to Seek Professional Help
Although many homeowners can successfully winterize their irrigation systems, some situations warrant professional assistance. Here are some examples:
If the issue persists: If you’ve tried the troubleshooting steps mentioned above but the air continues to escape from the backflow preventer, it’s time to call in a professional. There may be internal damage that needs to be addressed.
If you’re uncomfortable working with your system: Winterizing an irrigation system can be challenging. If you lack experience, the best option is to hire a professional.
If you’re unsure of the proper procedures: If you’re unsure about any part of the winterization process, seek professional help. Mistakes can be costly.
Conclusion
In conclusion, the problem of air coming out of backflow during winterization is often a sign of an underlying issue. Understanding the function of your backflow preventer and the causes of this problem will equip you to address it effectively. By following the troubleshooting steps and taking preventive measures, you can protect your irrigation system from winter’s cold embrace. Remember, consistent maintenance and prompt attention to any issues will help ensure your system’s longevity and reliable performance. With proactive care, you can extend the life of your investment and avoid costly repairs. It is important that you are diligent and proactive in the care of your irrigation system.