Manifolds: Valve Boxes 101

Okay, so when I first started brainstorming about this post, my mind went in multiple directions. And I’m not going to lie, one of them was definitely a terrible dad joke along the lines of, “Manifolds? More like Man I’m full …of pipes”. It’s cringeworthy at best, I know. But let me at least try to explain my bad dad humor on this one.

According to Merriam-Webster, a manifold in relation to mechanics is: “A pipe fitting with several lateral outlets for connecting one pipe with others.” I like to think of an irrigation manifold as the “heart” your system. It’s the place that all of your water flows to be separated out into different lines, that then supply that “life water” to the body that is your landscaping.

Dramatic? …Yes.

But does it paint a darn good picture? I’d like to think so.

Above is beautifully drawn diagram of a simplified, residential manifold. There are a few items that I have circled in red. One of them being “valve box”. The valve box encases your pipe manifold and allows easy access to it (as it is all underground) with a lid. …See? Dad joke. …manifold …full of pipes… get it? Maybe?

Ok, let’s move on.

In total there are three main components to each valve plus a valve box to encase those components. Those components are:

1. Electric Valve
2. Wye Strainer
3. Pressure Regulator

So, the best path in understanding a manifold, or valve box is to briefly discuss each of its components in turn.

1. Electric Valve

The image below is a Hunter PGV Electric valve. This valve (or similar valves) is pretty common for residential settings, and what I will use in reference to electric valves in this blog.

Now, I could get really in depth on how this valve works. But for the sake of “briefly” discussing what an electric valve is, the three parts noted in the picture are all you need to know about (…for now). An electric valve has a few key functions that are integral to most irrigation systems.

Each valve is hardwired into an irrigation clock. One valve equates to one station on your clock. By programming your clock’s run times for each station, you are effectively deciding which valve runs at what time, and the duration of that time. This is done by sending an electrical signal to the valve’s solenoid.  The solenoid then activates a spring on the inside that opens the valve, allowing water to pass through OR stop the water from continuing into your system. You can also manually turn on your valve by turning the solenoid counter clockwise a quarter turn. BUT BE AWARE! If you turn the solenoid to much, it will unscrew and water will pump out of the opening. If this occurs, turn off the water supply at the backflow, and reattach the solenoid to the valve. (For more information on backflows, see https://lookslikerain.store/blogs/news/backflow-prevention-it-s-spot-in-your-irrigation-system) The manual bleed screw will also turn the valve on and off. The last feature that is noted is the flow control. This part does exactly as its name states, it controls the flow, or the amount of the water to the station it is providing H₂0 to.

2. Wye Strainer

The wye strainer (or wye filter) is the second component in our line-up. The purpose of this part is much simpler than the electric valve. A wye strainer is meant to filter out any particulate or organic matter that may have entered your system at any point prior to it. Each strainer contains a very fine mesh filter on the inside. The water flows through the filter and out of it, into a pressure regulator. This is important as particulate matter can build up in emitters, nozzles, and any other device that emits water, effectively blocking the natural flow of water through that part.

3. Pressure Reducer

Pressure Reducers are the third and final MAJOR component of a residential based manifold. As its name states, its purpose is to reduce the water pressure to a specific rate. The rate, or PSI is then maintained for the entire time the valve is open. Many irrigation emitters, sprinklers, bubblers, etc. have a maximum and minimum PSI rate. Operating outside of this range will make the device work improperly.

Manifolds can be very intimidating if you don’t understand the function of each part. But, by breaking its main components into smaller steps, the overall purpose of what a manifold is, and what it does becomes a lot more simplistic. Join us next week with the final “cornerstone” of a irrigation system, irrigation clocks!