Field guide
Guide to check valves
An irrigation check valve is designed to restrict reverse flow in a particular line. This diagram node currently has no listed check valves. An irrigation backflow preventer is a separate protection decision and may have a required approved design under local rules; a basic check valve should not be assumed to meet that requirement.
For a future product, record pipe size, operating pressure, flow direction and the water source. Ask a qualified installer or the local authority which backflow protection is required where fertilizer or chemicals may enter the water line.
Where and when to use it
An irrigation check valve permits flow in one direction and helps prevent reverse flow in a designed line. No check-valve products are currently listed on this route. A check valve used to protect a pump or maintain line direction is not automatically an approved irrigation backflow preventer for a potable source or chemigation setup. Identify the protection objective and local requirements first.
How it works
A spring, flap or other mechanism closes when flow reverses or pressure changes. Its cracking pressure and head loss can affect pump performance. Source-protection assemblies may require multiple devices, test ports and inspection; a single catalog check valve may not satisfy those rules. For fertilizer injection, a qualified design should address both the main water line and injection line.
How to plan and install it
- Define whether the task is pump protection, flow direction or regulated source protection.
- Check local cross-connection and chemigation rules and select approved devices where required.
- Match valve size, pressure, material and flow direction to the line.
- Install access for testing and verify forward pressure loss and reverse closure.
Operation and maintenance
Inspect for sticking, debris and leakage according to the valve manual. Test source-protection assemblies on the schedule required locally. A valve that does not close fully can allow contaminated backflow, so isolate the line and investigate promptly. This page has no listed hardware to purchase now.
Common questions
Do I need a check valve on my irrigation system?
A check valve may be needed for a specific reverse-flow or pump-protection problem, but it is not automatically an approved backflow-prevention assembly. Define the water-source risk and any injection use, then follow local requirements and the equipment manufacturer's placement instructions.
Where does a check valve go in an irrigation system?
Its location follows the reverse-flow risk and equipment instructions, often near a pump or protected branch, with access for inspection.
Technical reference: UGA Extension, Fertilizer Injectors: Selection, Maintenance and Calibration. Use the selected product manual and local requirements for final design.