Bleeding an irrigation valve typically involves manipulating the valve's bleed screw to release trapped air or manually operate the valve.
Understanding the Bleed Screw
Many automatic irrigation valves are equipped with a small bleed screw (sometimes called a manual bleed or vent screw). This component serves a crucial function:
- Releasing Air: Air trapped in the system can prevent the valve from operating correctly. Opening the bleed screw allows this air to escape.
- Manual Operation: The bleed screw can often be used to open the valve manually, which is useful for testing the system or flushing lines.
The Bleeding Process
Based on information like the reference from a video titled "Rain Bird - Using the Bleed Screw to Fix a Sprinkler Leak," the fundamental action involves turning this specific screw.
Here is the general process:
- Locate the Bleed Screw: Find the small screw on the body of the irrigation valve.
- Prepare for Water Release: Be aware that water will escape when you open the screw. Ensure the area is ready for this water flow.
- Turn the Screw: Slowly turn the bleed screw counterclockwise.
- Observe Water Flow: Continue turning until water starts to escape from the top of the valve. This indicates that air is being pushed out or the valve is beginning to open manually.
- Control the Flow: You can adjust how much water escapes by slightly tightening or loosening the screw.
- Close When Done: Once you have achieved your purpose (e.g., clearing air, flushing), slowly turn the bleed screw clockwise to close it completely.
Important Safety Note: As highlighted in the reference, you should "Never completely remove the bleed screw on a live" valve (meaning a valve with pressure on it). Removing it fully under pressure can cause a significant water eruption and potential damage or injury.
Why Bleed a Valve?
You might need to bleed an irrigation valve for several reasons:
- Troubleshooting: If a zone isn't turning on, bleeding the valve manually can help determine if the issue is with the valve itself or the electrical signal from the controller.
- Clearing Air: After system maintenance, repairs, or initial installation, air can become trapped, causing erratic sprinkler performance. Bleeding helps remove this air.
- Flushing Lines: Manually opening the valve via the bleed screw can help flush debris from the main line or lateral lines.
Bleeding the valve using the bleed screw is a common and effective way to diagnose and resolve issues related to air or manual operation in an irrigation system.
