As any irrigation maintenance contractor can tell you, every irrigation system will eventually
need repairs and in some cases complete renovation.
If a renovation is required, then you will likely be replacing a valve manifold.
A valve manifold is a collection of irrigation valves assembled together, and connected to
a common supply line.
In the case of drip irrigation, the manifold will also include a y-filter and pressure
regulator for each drip hydrozone.
The first step to building a new manifold is to expose the current assemblies to see
what you have to work with.
You'll need to determine the size and quantity of valves you'll need, the size of the incoming
supply line, as well as the lateral lines going to the landscape.
Using this information, draw up a rough sketch to help you figure out the materials you'll
need to build and connect the new manifold to the water supply.
If located below grade, the size of your new manifold will determine the size valve box
you will need to house it.
This particular job is pretty straight forward with only two drip zones.
But the new plan includes the addition of a flow meter, and master valve.
The flow meter will measure and monitor the flow of water through the system.
Should an event occur that reduces or increases the normal flow of water, such as a valve
that won't open or break in the line, the wifi enabled Hunter Pro-HC smart controller
we plan to install will send an alert to the home owner notifying them of the problem.
A master valve acts as a fail safe to help prevent water waste.
It's located upstream from the manifold and is opened and closed along with the zone valves
during each irrigation cycle.
Should a zone valve leak or not close all the way, the master valve will act as a back
up.
With a plan and materials on hand, the first step is to turn off the water supply at it's
source.
It's also a good idea to disconnect the power to the controller.
Next, cut the pipe connecting the supply and lateral lines to the manifold taking care
to protect the exposed lines to dirt and debris.
Also, disconnect the valve wires going to the controller and label them so you know
which wires control each zone.
Finally, remove the old assembly and excavate the area wide and deep enough to hold the
new valve box.
The top of the valve box should sit level and a couple inches above grade.
Since we are using a flowmeter in our example we will install it first.
This particular flowmeter from Hunter needs to be installed between the water supply and
the master valve and needs at least 12 inches of straight irrigation line on either side
for proper operation.
We used a female adapter to connect the flow meter to the supply line and another on the
downstream side that will lead to the master valve.
We followed the same procedure for the master valve except we used two male adapters to
connect to the PVC pipe.
Moving on the to the main manifold, with proper planning you can assemble parts ahead of time
and then connect the entire unit to the supply and lateral lines.
Like the master valve we used a male adapter to connect our Hunter drip zone kits to the
manifold.
When cutting the pipe that connects the valves together be sure to measure accurately to
leave enough room between them for future maintenance but not so much that the assembly
won't fit into the valve box.
To support the possibility of additional hydrozones, we designed our manifold with the stub-out
that we will cap off for future use.
With the manifold assembled, the next step is to connect the unit to the supply and lateral
lines.
Use a brick or something similar to support the weight of the manifold while you solvent
weld it to the supply line.
Once all the connections are made and the glue has had time to set up, make sure the
valve solenoid are in the off position, except for the master valve if you used one, and
then slowly turn the water supply back on to test for leaks.
Next, manually open each zone to flush out any debris that may have gotten into the system
during construction.
Drip systems should have a flush cap at the end of each run and if using sprinklers you
can remove the nozzle from the last head in each zone.
Be sure to turn the master valve solenoid back to the off position when done.
Now you can connect the solenoid wires to the controller as well as the wires from the
master valve and flow sensor if you used them in your system.
Check the manufacturers guide for detailed instructions on wiring.
Once wired, test each zone using the controller's manual operation.
All that's left to do now is to add the valve box.
In addition to the large valve box for the manifold, we also used two small round valve
boxes to protect the master valve and the flow meter.
You may need to cut out sections of each valve box to allow them to fit over the water supply
line.
You can also use bricks to support the manifold valve box as well as prevent dirt from making
its way into the bottom of the valve box over time.
Finally, to help with drainage, add a few inches of pea-gravel to the bottom of the
valve box just below the manifold.
Now, every situation is different, but what we've demonstrated to help you get started
on your project.
You can find all the products we used in this video at your local Ewing branch or by visiting
us online at ewingirrigation.com.