Introduction to Irrigation Controllers, Manifolds, and Valves

Once you have delved into the world of irrigation it will not be long before you begin to expand your system to include other aspects of irrigation.  Once your project has grown to a certain size you will find the need to zone your system.  Zoning a system is most often done for several reasons, among them: the flow rate of the water supply cannot keep up with the demand of the emitters, different plants and landscaping have differing hydration needs, the property is large and needs to be divided, or a combination of all of the above. That’s where manifolds and valves come in.   

The following article is meant as an introduction to these concepts and is by no means a comprehensive training guide that includes everything one needs to know in order to set up an automatic valve system. The ideas presented here are meant to introduce the basic concepts to the avid DIY’er and create a foundation from which to build. 

Controller

A manifold and valve system start with a controller.  Think of it as the brain of the system.  The controller is similar to a timer in that it opens valves at specific programmed times and durations, however unlike common hose end timers the controller does not have its own valve.  Controllers are connected to the valves by running a wire from the controller to the valve itself.  

Controllers can be either AC or DC. AC controllers are not compatible with DC valves and vice versa. This means if you have a DC controller you will need DC valves. Controllers do not attach to a hose or faucet. They are typically mounted on a wall inside or outside. Some must be hardwired directly into the electricity, some come with an external transformer that can be plugged into a wall outlet and some are battery-operated.    

You can see a list of available controllers here: Irrigation Controllers.

Manifold

Manifold: noun: a pipe or chamber branching into several openings.  As the definition suggests, an irrigation manifold is a pipe that branches into several openings, in this case, to deliver water to multiple irrigation valves. The manifold is typically fed by pipe or tubing that is tapped directly into the house’s water supply, but it is also possible to supply it by a faucet or hose connection.  

Manifolds come in many different sizes depending on how many valves and zones are needed. The one pictured above is for a two-zone system, but options exist for much larger setups. We offer Manifold Kits for up to six zones. Thanks to products like PVC-Lock it is now easier than ever for the homeowner to assemble their own manifold system.  

You can see a list of available Manifold Kits here: Manifold Assembly Kits.

Available manifold parts can be found here: Manifold Parts.

Valves

There are many types of irrigation valves.  In this article we will focus on solenoid valves, the kind usually found in automatic irrigation and sprinkler systems. Solenoid valves consist of the valve itself, which is the part that opens and closes to allow or restrict water flow to the system beyond it, and the solenoid. The solenoid is the part of the valve assembly that is wired directly to the controller. The controller sends a signal to the solenoid which then opens or closes the valve.  

One side of the valve connects to the manifold; this is known as the inlet. The inlet will be under constant pressure and allows water to pass through only when opened by the controller. The other side of the valve (outlet) connects to your lateral lines. Lateral lines are the pipes or tubing that carry water from your valves to your emission devices, typical sprinklers in a setup like this. Lateral lines are only under pressure when the valve is open and water is allowed to flow through.  

A list of our valves by the brand can be found here: Irrigation Valves.

Valve Boxes   

The manifold and valves are usually buried underground. To protect them from the elements and allow easy access for maintenance and repairs, they should be placed in a valve box. Valve boxes come in a variety of shapes and sizes to fit the needs of the system. From round to rectangle, to as small as six inches or as large as twenty-one inches, a valve box can be found to fit almost any common residential setup.  

Our valve boxes are created from HDPE for strength and chemical resistance. They are able to withstand light pedestrian traffic, however, care should be taken to avoid any vehicle traffic as this could cause irreparable damage.

You can see our selection of valve boxes and valve box lids here:  Valve Boxes and Replacement Lids.