Do I need anti siphon sprinkler valves?
Matthew Barrera
Published Jun 04, 2026
Do I need anti siphon sprinkler valves?
Isn’t it an anti siphon valve? If your sprinkler heads are above the level of the valve, you don’t need them. Unless your heads are above the valve, the risk of backflow is low because the lines in your house are pressurized by the water.
Do you have to have a backflow preventer on sprinkler system?
The key to preventing backflow is to have a properly installed, maintained, and inspected backflow prevention device as part of your culinary water system. The answer is: you need backflow prevention if you have a culinary water connection that may be used to supply a sprinkler system.
Where should I install anti siphon valve?
When installing a siphon valve it is best to place it directly after the isolation valve in the pipe system. The isolation valve is the main shut-off valve for your sprinkler system. It is usually placed directly after the coupling made with the main water line in your plumbing system.
What is an anti siphon valve on a sprinkler system?
An anti-siphon valve is a very important part of an irrigation system. It performs many functions. As a combination control valve and atmospheric back-flow preventer, it is responsible for holding water under pressure for your sprinkler lines.
Do anti siphon valves reduce water pressure?
They are supposed to prevent water from flowing backward if the city water pressure were to suddenly drop. These one way valves always leak and if you turn off the faucet while the garden hose is pressurized, the anti-siphon valve will discharge the pressure in the hose through some vent holes.
What is a backflow device for sprinklers system?
Sprinkler System Backflow Preventer A backflow prevention device is attached to the main water line from your home and prevents water from flowing back into your home’s pipes. This is to prevent any contaminants from reaching your drinking water. It only allows water to flow in one direction, thus avoiding backflow.
Where is a backflow preventer installed?
There are three options for backflow preventer installation: inside a vault, inside a building, along with outside and above ground in an enclosure. This backflow preventer installation guide details each method and highlights why we recommend installing backflow preventers above ground and outside as a best practice.
When would you use an anti siphon valve?
Anti-siphoning capabilities are required by code on certain plumbing devices, such as exterior faucets (sill-cocks) or utility sink faucets. Anti-siphon devices protect against the possibility of a low water-pressure event in the supply line sucking contaminated water back into the potable water supply.
What is the best backflow preventer?
Best backflow preventers for sprinkler systems comparison table
| Maximum working water pressure | ||
|---|---|---|
| Zurn 1-720A Wilkins pressure vacuum breaker | 150 PSI | Check here |
| Febco 765-1” BV pressure breaker | 150 PSI | Check here |
| Mueller B & K 108-904RP backflow preventer | 125 PSI | Check here |
| Homewerks Worldwide VACBFPZ4B breaker | 125 PSI | Check here |
Can I use a check valve instead of a backflow preventer?
check valves. And we clear up a misconception that’s often inquired about in online forums: while check valves have other important applications, they cannot be considered a safe substitute for backflow preventers when it comes to protecting the purity of drinking water.
Is there an anti siphon device in California?
It is not just a California thing. They are everywhere. An anti-siphon device (or vacuum breaker) prevents unsanitary water from being pulled back through a garden hose and contaminating your water system. Otherwise known as a “Cross Connection” I always look for them and report if they are present or not.
Do you need an anti siphon device for a garden hose?
An anti-siphon device (or vacuum breaker) prevents unsanitary water from being pulled back through a garden hose and contaminating your water system. Otherwise known as a “Cross Connection” I always look for them and report if they are present or not. I believe most building codes require them on homes built.
How does an anti siphon valve on a faucet work?
These one way valves always leak and if you turn off the faucet while the garden hose is pressurized, the anti-siphon valve will discharge the pressure in the hose through some vent holes. This is when you Anti-siphon device on outside faucets? Specific Inspection Topics Plumbing Inspections
Why do you need an anti siphon valve for a sprinkler system?
It’s the most essential sprinkler valve because the anti-siphon valve is responsible for protecting your home from non potable water. Almost all homes get pressured water from a city water line. A separate water line runs from the city line toward your house. Once the water line gets near your house it meets a cross section that creates a new line.
Where can I buy a new anti siphon valve?
Take the old anti-siphon valve to your local home improvement center and purchase a replacement. If possible, purchase a replacement anti-siphon valve that is the exact same size as the old one.
It is not just a California thing. They are everywhere. An anti-siphon device (or vacuum breaker) prevents unsanitary water from being pulled back through a garden hose and contaminating your water system. Otherwise known as a “Cross Connection” I always look for them and report if they are present or not.
An anti-siphon device (or vacuum breaker) prevents unsanitary water from being pulled back through a garden hose and contaminating your water system. Otherwise known as a “Cross Connection” I always look for them and report if they are present or not. I believe most building codes require them on homes built.
