Do I Need an Automatic Drain Valve on my Sprinker?

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For those who haven’t worked with sprinkler systems very much, you might be concerned about how your sprinkler system functions and how it will handle the excess water in the pipes. Depending on where you live and how your sprinkler system is set up, you might need to ensure that you have an automatic drain valve on your sprinkler system.

All sprinkler systems should include an automatic drain valve in order to avoid damage to the pipes and other system components. Without one, water will be trapped in the pipes, which will beak when the water freezes. Having an automatic drain valve will also keep water from sitting in the pipes.

Here’s everything that you need to know about these sprinkler drain valves.

King Drains

Automatic drain valves (also known as king drains) are plastic components of sprinkler systems that give an avenue for the water in the pipes to drain out of. They attach to the system of pipes, slowly releasing the water after the sprinklers have all run. The nice thing about king drains is that they do this automatically and don’t require your sprinkler system to run any kind of emptying process to drain the water.

King drains have a few valuable properties to them. First of all, king drains have a filter on the end, which keeps any dirt or any rocks from getting into the pipes. If anything like that enters the pipes, the water pressure will blast the pebbles or dirt into the sprinkler heads, which can damage the sprinklers extremely easily. Furthermore, if rocks get stuck inside of a sprinkler head, the water flow and angle can be disrupted, which might prevent grass from getting water. In hotter climates, spots on your lawn could quickly die as a result.

Another important aspect of king drains is that they do not emit water while under pressure. When the sprinklers are running and the water is pressurized through the pipes, the king drains will not drain the water. Once the cycle has ended and the pressure is gone, the king drain will begin to empty the water from the pipes.

Damage to Systems

The reason that king drains are so important is that it is not good for a sprinkler system to have water sitting in it. Though the PVC pipe will handle the water in its liquid state, the water is likely to freeze and expand, bursting the pipes and causing enough damage that the entire system will need to be replaced. Sprinkler systems can be extremely expensive to replace, especially if multiple systems are needed to cover your lawn.

During the summer, freezing water isn’t as much of a problem because it probably won’t get cold enough for the water to freeze. However, freezing nights can come sooner than expected, and relying on methods other than an automatic drain valve can be risky.

If your sprinkler system does not already have an automatic drain valve, you can add one to the system yourself or you can use an air compressor to blow all of the water in the pipes out through the sprinkler heads.

How to Install an Automatic Drain Valve

If your sprinkler system does not already have its own automatic drain valves, you can add them fairly easily by yourself. First, you will need to count how many different sprinkler lines you have in your system. One easy way to do this is by counting how many different valves you have in the valve boxes on your property. Most houses have one valve box for the sprinkler system that covers the front lawn and one for the system that covers the back yard (though some have more valve boxes).

Each valve will correspond to one sprinkler line, covering one segment of a lawn. Your average sprinkler line will have 3-6 sprinkler heads on them. Each individual line will need its own automatic drain valve, so you will need to purchase one king drain for each valve that you find on your property, one elbow or tee connector (with the threads that the king drain will attack to on one side) and possibly a slip-fix connector to reattach the pipe once you attach the drain.

The next step for installing king drains on your sprinkler systems is to find out where each valve leads to. You can twist a knob on each valve to discover which valve corresponds to which section of your lawn. Trace out where the pipes are laid in order to discover where you can add the king drain. If you need to, dig down a foot or two in order to ensure that the pipe is where you think it is.

You should add the king drains to the part of the sprinkler line that is the lowest in elevation and furthest away from your house. The lower that the king drain is, the better job it will do at draining the water. However, if you are draining water close to your house, the water could seep down and weaken the foundation of the house.

Once you have identified the part of the sprinkler line that you will add the king drain to, dig down to the pipe. If you are adding the drain to the end of a pipe, use an elbow to connect the king drain to the pipe. If you are adding the drain to the middle of a pipe, use a tee connector. Use a saw to cut into the pipe and rubber cement to glue on the connector with the king drain attached.

If you do not have enough space to add a tee connector with a king drain to a length of pipe, you can cut off a little extra pipe and attach a piece of PVC called a slip fix, which is made to compress down and then extend out to fit into the other end of your connector.

Once you have a king drain on every sprinkler line, you can rest easy knowing that your pipes are safe from freezing.

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