How to Install an Anti-Siphon Sprinkler Valve

What You'll Need
Metal pipe
Anti siphon valve
Plumbers Teflon tape
Adjustable or pipe wrench
PVC glue
PVC primer
PVC pipe
PVC elbow fitting
Hack saw

An anti siphon sprinkler valve prevents water that may have been contaminated from flowing back into the piping that leads to your main water supple. When it is installed in a water sprinkler system, the possibility that toxic chemicals and fertilizers could contaminate the water is always a possibility and to make sure that it does not happen, an anti siphon valve is used. It is the cheapest way of doing it and it is easy to install. With just a few tools and a simple guide, you will be able to finish the project in no time.

Step 1 - Knowing the Set Up

Before going into the project, you should know that an anti siphon valve should be installed at least 6 inches higher than all of the head valves in the sprinkler system. If it is not installed this way, the back flow prevention mechanism that was built into the valve will not be able to do its job. In addition, there is the Universal Plumbers Code or UPS that is required by almost all localities. The code states that the inlet side pipe on the anti siphon valve should be of metal construction, unless you will have to bury it by 18 inches or deeper. Any kind of metal pipe that has a pressure rating can be used for it.

Step 2 - Placing the Siphon Valve

In installing the siphon valve, you should put it directly in front of the isolation valve in the system. The isolation valve works as the main shut off valve of the water sprinkler system. Usually, it is installed directly after a coupling in the main water line of the plumbing system. It should be around 6 to 18 inches above the ground so that when you install your anti siphon valve, it will remain higher than all the sprinkler heads.

Step 3 - Installing the Inlet Pipe

In installing the inlet pipe, get a piece of metal pipe that has been threaded at both ends. Insert one end into the isolation valve and the other end into the metal elbow that has the same diameter as the pipe. Ensure that both ends have been wrapped with Teflon tape before you tighten it.

Step 4 - Installing the Siphon Valve

Wrap Teflon tape around the male end of the anti siphon valve and connect it with the metal elbow connector. It the end has not been threaded put a short piece of pipe that has a male threading on both ends. You can then install the anti siphon valve.

Step 5 - Installing Your First Sprinkler Head

A lot of anti siphon valves can be bought with a sprinkler head but if you have purchased one without it, you have to install the sprinkler head with the use of a 3 inch PVC pipe. Put PVC primer on both ends of the pipe and on the female connectors. Secure them with the PVC glue.

Step 6 - Running the Pipe into the Sprinkler Heads

Install a vertical PVC pipe on the bottom of the sprinkler head and continue installing more. However, you have to make sure that the first PVC elbow has been installed at least 18 inches into the ground.