At NutraDrip Irrigation Systems, we know that the key to a successful subsurface drip irrigation system lies in the details. One of those crucial details is the pressure regulating valve. These valves do more than just turn zones on and off; they are integral to maintaining the proper pressure throughout your irrigation system. Here’s everything you need to know about them.
Understanding the Function of Pressure Regulating Valves
Pressure regulating valves are essential for ensuring that each drip zone operates at a specific pressure. They help prevent both under-pressurization and over-pressurization, which can harm your irrigation system.
These valves are called “regulating” because they limit the pressure that goes into the drip line; they cannot boost it. By maintaining a consistent pressure, they ensure your crops receive the optimal amount of water.
Components of Pressure Regulating Valves
Pressure regulating valves come in various sizes, commonly 3-inch and 2-inch. Each valve includes several key components:
Solenoid: Tied back to the controller to open and close the valve.
Pointing to the solenoid.
Pilot: The pressure regulator that can be adjusted to change the pressure.
Pointing to the pilot.
Valve Body: The main part of the valve with an arrow indicating the water flow direction.
Finger Filter: Located inside the valve to clean the water entering the solenoid, preventing debris from causing issues.
Bladder: Controls the opening and closing of the valve based on water pressure.
Bladder.
How Pressure Regulating Valves Work
Inside each valve is a bladder that moves up and down, using the system’s water pressure to control the valve. When the valve is closed, the pressure on top of the bonnet equals the incoming pressure, pushing it down. When the solenoid opens the valve, water is vented off, allowing the valve to open.
If you see water dripping out of the vent tube, it indicates the system is regulating pressure. This is normal and shows the system is working to maintain the set pressure. If you go to open a valve and there is no water coming out of the vent tube, there is probably something wrong.
Inside the valve, there is a spring that ensures a certain amount of static pressure. The primary purpose of this spring is to keep the valve closed when there’s no pressure in the system. When you first start your system, even with very low pressure, such as five or two pounds, the spring ensures that all valves remain closed. This mechanism guarantees that when you initiate the system with minimal pressure, the valve stays fully closed.
To clarify, the water sits on top of the diaphragm, pushing it down. When the pressure is released, the diaphragm moves up.
Adjusting Pressure and Troubleshooting
Adjusting the pressure involves the pilot, which has a jam nut that you can turn clockwise to increase pressure or counterclockwise to decrease it. Newer pilots, like the 2950 model, have a gauge to indicate pressure but should still be set using a pressure gauge for accuracy.
For quick troubleshooting, removing the spaghetti tube from the top of the valve bonnet can tell you a lot. If water comes out for a few seconds and you hear the valve open, the system is likely functioning correctly. No water flow or noise might indicate an issue with the solenoid or upstream pressure.
The Role of the Three-Way Selector
Some valves have a three-way selector with positions for open, close, or auto. This selector can bypass the solenoid and pressure regulator in open or close positions, but for normal operation, it should be set to auto. This ensures the solenoid controls the valve.
Maintaining Your Valves
Regular maintenance of the pressure regulating valves is crucial. Check for debris in the finger filter and ensure all components are in good working order. The valve diagram and troubleshooting guide in your connection diagram book are valuable resources.
Conclusion
Understanding and properly maintaining your pressure regulating valves will keep your subsurface drip irrigation system running smoothly. At NutraDrip, we’re here to help with all your irrigation needs, ensuring your crops get the precise amount of water they need. Stay tuned for more tips and guides on optimizing your irrigation system.
