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How Do Anti-Siphon Valves Work?

While watering your plants or grass, the anti-siphon valve allows water to flow from the water source to the irrigation system. However, if at any point the water supply pressure drops or is turned off, the valve prevents water from siphoning back into the main water supply by incorporating a built-in backflow prevention mechanism. This mechanism breaks the siphon effect that could draw contaminated water back.

Anti-Siphon Valve FAQs

Do I need an anti-siphon valve for my irrigation system?

If your irrigation system is connected to a potable water supply and does not already have a backflow prevention device installed, you need anti-siphon valves to protect the water supply from contamination. Anti-siphon sprinkler valves are also sometimes necessary to adhere to local plumbing codes.

Where should anti-siphon valves be installed?

Anti-siphon valves must be installed above ground, at least 6 inches higher than the highest sprinkler head or emitter in the irrigation zone. Since they function both as control valves and backflow preventers you’ll usually want to install them at the start of each irrigation zone.

How many anti-siphon valves do I need?

You need one anti-siphon valve for each irrigation zone. While most residential setups will only require a single valve, this also means that larger commercial setups will need an anti-siphon check valve for each section of a garden or lawn. Each valve acts as a control valve and a backflow preventer for its specific zone.

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Katy , TX 77449
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