Valve Series: Valve Operation

I'm Mike from Hunter Technical Support Department.
In this segment we'll be reviewing basic valve operations. If you're trying to locate
the valves in your yard,
here we have a typical installation
with four five valve boxes,
and here at this end is
a 1" ICV valve. It was installed with waterproof style connectors.
The wiring leads over here to the solenoid,
which is what electrically actuates the valve.
In the middle we have the flow control handle,
and the flow control handle regulates the amount of water that passes through the valve
when the valve opens.
In the center of that, we have the manual bleed screw.
That will manually actuate the valve,
and as well there is an Accu-Set pressure regulator
That's a field-installed accessory that allows you the dial in the exact pressure
that you want
for after the valve.
To manually operated valve,
one would take the solenoid and turn it a quarter turn
counterclockwise.
You'll hear the water start to flow
Let go of the solenoid,
and after you've done your field check on the heads and you're ready to turn the valve off,
simply
turn the solenoid
a quarter turn clockwise,
hand tight; Don't overdo it, you'll feel it stop;
and then you'll hear the water stop.
So, here we have an
ICV in line valve. On the topic of general valve operations, we'll start by identifying
the various parts of the valve
and here in the lower half
is the valve bod;
and the upper half of that is called the valve bonnet, and that's held down by the screws.
In the center portion we have the working part of the valve. It's called the diaphragm,
and on top of the diaphragm
we have the center stem that goes up to a flow control handle.
The flow control handle regulates how far the diaphragm opens
and allows water to go through when the valve does open.
On top of the flow control screw
we have what's called the manual bleeder screw;
and opening the manual bleeder screw allows the water to evacuate out through that hole
and allow the diaphragm to open thus the valve will open with it.
Beyond that, we have the solenoid, and that's what receives the electricity
from the controller
The solenoid has a plunger on the bottom;
When it's electrically activated, the plunger will raise up;
and when it raises up that little rubber gasket comes off of its port and allows
the water to go down the exhaust port thus decreasing the pressure on top of the diaphragm,
alowing the diaphragm to move up
and allowing the water to flow
out to the field.
The diaphragm operates off of something called surface area differential;
and as you can see the diaphragm sits horizontally in the valve.
The top surface on the diaphragm
here is much larger in diameter
than the bottom side as you can see here.
So, the difference in surface area is what creates the differential.
The top portion of the valve has something called the bonnet chamber; and you can see that
inside here,
at idle,
the diaphragm sits down on the diaphragm seat
and there is no
escape of the water here on top, so it's pressurized.
The plunger is down. It's not allowing water to escape so that pressure sits on top of that
diaphragm.
When the controller turns on the valve electrically,
the plunger raises up
and the pressure and water that sits on top of the diagram is allowed to escape
down the exhaust port
and downstream
once the water escapes, the pressure here drops
and it allows this diaphragm to move upwards off of its seat
allowing the water to escape downstream to the heads.
You might also have something called anti-siphon valve.
This is not an in line valve that goes in a valve box but it mounts above ground usually
about 16"
up grage;
And this happens to be a slip joint style,
but it works off the same premise:
the front half is the anti-siphon portion
and the back half has the body,
the diaphragm in between, the same flow control,
and the same solenoid, and the manual bleeder screw and this is held down by
by four screws;
and the larger ICV valve
is held down by
the six screws.
So that's the basic premise of how valves work.