In the winter season, it is necessary to drain all the water from the irrigation system, especially the sprinkler system, to avoid costly damages.
The solution lies in understanding and implementing proper drainage technology, specifically automatic drain valves for sprinkler irrigation systems.
Whether you’re a homeowner maintaining a residential lawn sprinkler system, a facility manager overseeing commercial irrigation, or a landscaping professional serving multiple clients, this comprehensive guide will equip you with everything you need to know about automatic drain valves and how they can safeguard your irrigation investment.
What Is an Automatic Drain Valve for Sprinkler Irrigation System?
As the name suggests, it automatically drains the system water after the pressure drops below predetermined levels.
Unlike manual drain valves that require human intervention, these ingenious devices operate independently, providing continuous protection against freeze damage without requiring seasonal maintenance or monitoring.
The working mechanism of the drainage valves is simple: when the sprinkler system is pressurized and operating normally, the valve remains closed, allowing water to flow through your irrigation lines as intended. However, when the system shuts down and pressure drops, typically below 10 PSI, the valve automatically opens, allowing trapped water to drain from the lowest points in your system.
This automatic operation is what makes these valves so valuable for irrigation system protection. They eliminate the human error factor that often leads to freeze damage when manual valves are forgotten or improperly operated during seasonal shutdowns.
Type of Automatic Drain Valves: Choosing the Right Solution
The irrigation industry offers several types of drain valves for specific application requirements and installation conditions.
Understanding these options helps you make a better decision by selecting appropriate drain valves.
Spring-Loaded Automatic Drain Valves
This is the common type of drain valve used in residential and light commercial applications.
These valves use a calibrated spring mechanism to control opening and closing based on pressure differential.
They’re typically installed at the lowest points in irrigation zones and provide reliable operation with minimal maintenance requirements. The spring mechanism is simple, durable, and less prone to failure than more complex valve types.
Combination of Automatic/Manual Drain Valve
These kinds of drain valves offer both automatic and manual functions to control drainage.
Using these types of drain valves, you can manually drain systems for maintenance or repairs while still providing automatic protection during normal operation.
The manual override feature is particularly valuable for service technicians who need to completely drain system sections during repair work.
Diapharm-Type Automatic Drain Valve
This is the automatic drain valve that responds to pressure changes.
These valves often provide more precise pressure control than spring-loaded versions and may offer better resistance to debris contamination.
They’re commonly used in commercial applications where consistent performance is critical.
Low Profile Automatic Drain Valve
These drain valves are designed for installation where space constraints or aesthetic considerations are important.
These compact valves provide the same protection as standard versions while minimizing their visual impact on landscape installations.
Season Consideration and Best Practices
For effective use, automatic drain valves require understanding seasonal variations and implementing best practices that ensure year-round system protection and optimal performance.
Pre-Winter Preparation
Before winter hits, it is important to thoroughly inspect, clean, and test the drain valves to verify proper operation.
This preparation ensures valves will function reliably when freezing conditions occur and helps identify any issues that require attention before the winter shutdown.
Winter Monitoring
During the winter, you don’t need to regularly check the drain valves—occasional verification provides peace of mind and early problem detection.
Periodic checks ensure the valves are working properly and the system is adequately drained.
Spring Startup Procedure
If you haven’t periodically checked the drain valves during the winter, it is important to inspect the system to identify any issues that may have developed during the shutdown period.
Early problem detection allows for repairs before the active irrigation season and prevents minor issues from becoming major problems.
Summer Operation Management
It is also important to ensure valves remain closed during normal system operation while maintaining readiness for emergency drainage if needed. Regular monitoring helps identify performance issues and maintains optimal system efficiency.
List of Best Automatic Drain Valves For Sprinkler System
Orbit Automatic Drain Sprinkler Valve
This is a simple automatic drain valve for sprinklers. You just need a T to install this on your existing sprinkler system, and it will automatically drain out the water in the pipe when the system is off.
Auto drain protects irrigation pipes from freezing in colder climates where that might be an issue. The auto drain has 1/2-inch or 3/4-inch male pipe threads (MPT), which thread into the outlet of a tee or elbow at the low points of the piping for a zone.
The auto drain has a seal that closes when the valve turns on and pressurizes the zone, and opens when the valve turns off. This allows the line to be empty when the zone is not in use.
However, this also means that the water from the zone, about 4 gallons in a 100-foot section of pipe, will drain into the ground after each cycle. So you should only use drain valves where the risk of pipes freezing during the irrigation season is high or the system cannot otherwise be properly winterized at the end of the season. For outdoor irrigation use with cold water only.
Rain Bird 16AFDVC1 Sprinkler System Filtered Drain Valve
This is a smaller drain valve compared to the Orbit; however, it offers the same features and is even suitable for underground sprinkler systems.
The valve has a 1/2″ male thread connection and automatically drains pipes after each use to prevent freeze damage. It eliminates the need for expensive and time-consuming gravel drains.
Remember, it is best practice to install at a low point in your system to drain pipes after each use to prevent freeze damage to sprinklers and piping.
The unique two-stage screening process prevents grit from siphoning back into pipes. A plastic perforated cap screens out large particles, while a dispersion pad filters out small particles. Rain Bird — The Intelligent Use of Water.
Toro 53470 Sprinkler System Automatic Drain Valve
It has a sleek design to fit into any sprinkler system. This 1/2-inch drain valve drains the water from the pipe to prevent freezing.
Even with its small design, the valve automatically opens when the system is off and closes when the system is running.
The product fits well into any other brand of irrigation system.
Gardena Sprinkler System Drain Valve
Gardena is a German-made brand for passionate gardeners, and the drain valve is part of their sprinkler system.
The drain valve is made from metal to prevent frost damage to the system installed underground, and also has a strainer to filter out debris.
The valve automatically drains when the system is taken out of operation. The valve opens when there is a water pressure of approximately. 0.2 bar in the system.
Drain valves should be installed at the lowest point of the irrigation system and, for safe drainage, installed in a pack of washed coarse gravel.
Orbit Automatic Sprinkler Drain Valve
The difference between the previous Orbit drain valve and this one is the brass body, designed to fix to the hose pipe.
It has an operating pressure of 5 PSI and 1/2-inch male threading.
This drain valve seals when irrigation system water is running and does not drain until water pressure alleviates. For all your yard sprinkler systems draining, this sprinkler system automatic drain valve is perfect. It helps prevent freezing damage to sprinkler lines and has a corrosion-resistant spring and plunger.
Final Word…
The automatic drain valve is the insurance policy against freeze damage control.
The modest investment in automatic drain valves pays dividends through prevented damage, reduced maintenance requirements, and extended system life.
Whether you’re protecting a residential lawn sprinkler system or managing complex commercial irrigation infrastructure, automatic drain valves provide reliable, maintenance-free protection that preserves your investment and ensures reliable system performance year after year.
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