Evaporation can cause an irrigation system to waste a significant amount of water.

In Part 2 of our Drought Solutions video series, Bob Franchetto, DBDS Maintenance & Construction, shows you how to quickly minimize evaporation through pressure regulation.

Video Transcription

Minimize evaporation. How many times do we see this every day? Or better than that, how many times do we see this? We see this every day for sure.

What is your standard operating pressure here in San Diego? What's your static pressure? Ok, so you're 50 or 60? 50 or 60 static pressure?

Yesterday static pressure was 80 sitting at the store and working pressure was about 65. 65 psi on a gear drive rotor is too much. They're 40 to 55, 40 to 60. You know, too much and you get a lot of evaporation.

What's the standard operating pressure for a standard spray nozzle? Little low.

30. 30 psi. So on the same system when we got sprays, at 65 coming in, you're gonna have a ton of the atomization of the water and that's evaporation.

There goes your 20% savings. Let alone this property manager is not real happy with as much moisture as he's got on all of his sidewalks and his building.

What to Do When You Have Too Much Pressure

These are opportunities. If we're going to fix this, how would we fix that? This is a gear drive rotor. How would we fix that pressure?

Pressure regulator. So everybody knows we could put a brass pressure regulator on the whole system and knock that pressure down.

So, if we we're gonna change just this one valve that's running right here. How would we change of pressure on just that one valve?

Does everybody know what a PRS dial is? Every manufacturer makes one. This happens to be Rain Bird's. It's a PRS dial.

You take the standard solenoid off your valve. Pull it out. Install this piece. Put your solenoid back on top. So now you've got this assembly that's like that on top of your solenoid. Screw this device in and this is your dial regulator, and I'll send it around.

And now you can dial in whatever pressure you want that system to work at. Not a shovel one came out of the ground.

It's called a PRS dial. A pressure regulating stem, because that's Rain Bird's pressure regulation.

How to Check Pressure

It's got a little Schrader valve on the back side. So you can check to see that that pressure that it actually is reading on that dial is what you're getting.

Better than that, take your pitot tube and go out to this nozzle right here and check what the pressure is. Cause that's where we want the pressure to be. So we may be at 50 psi here at the valve, but now we're at 45 at the nozzle and that's perfect.

And that's what we want. That's how we get the most efficient system. Water going out in proper droplet size and not evaporating. That's how we do it.

This is the little dial device. You can see, mess with the dial, it moves. Real, real simple way, without digging, to change pressure.

Changing Pressure in an Irrigation System

Can you change pressure any other way on a system? How do you make pressure go up on a system? There's only one way. Simple. A pump. You can only make pressure go up with a pump.

There's only one way to make pressure go down. Pressure regulator.

So now I'm gonna get the question of, "Oh no. You can make pressure go down! All you gotta do is cut down on the flow control."

We've got smart guys in here. Cause that always comes up. Every time.

That doesn't change pressure. That changes velocity. How fast the water is going through the valve. That's all that does. Velocity changes will look like pressure reduction, but that's not what it is. Cause your pressure is still the same on the incoming and the outgoing unless you have a PRS dial or some sort of regulator on it.

When you change velocity, that's fine tuning that valve. And is everybody fine tuned every valve out there in the system? Sure we have!

How to Fine Tune a Valve

Does everybody know how to fine tune a valve?

Let's say we're fine tuning this one right here. Simple. No matter what valve it is. If it has a flow control, get in that valve box when the system is running and you crank this flow control down until you see that system start to fail.

As soon as you see it start to fail, back it off about 1 1/2 turns and let it sit.

Your valves will now close at a more even rate. They'll close quicker and there's almost no way for this valve to stick on now.

The majority of the time when a valve sticks on, it's because the diaphragm gets shoved up into the top of that bonnet cavity so far that it creates a small vacuum up there and that assist spring that's in there isn't strong enough to break that vacuum. And the valve sticks on. Controller can be completely turned off, but your valves sticks on.

You fine tune, you tune your valves. Now you're keeping more water on top of the diaphragm. It aids in the closing.

4 Types of Pressure Regulators

Pressure, we just went through all the pressures.
1. Pressures may be reduced with a pressure regulator for the entire system.
2. Pressure may be reduced at the valve using a PRS dial.
3. Pressure may be reduced using a PRS spray body. That's a huge one. We're going to talk more about that.
4. Pressure may be reduced using a pressure regulator built into the control valve.

And minor pressure reductions may be made using the valve's flow control. True or false? False statement. There's a lot of folks that think that's true.

"Oh, I change the pressure. I cranked down on the flow control."

No, you didn't. That pressure is still 45, 55, 65, 75 going through that.

Every valve should be fine tuned. 99% of the valve boxes I go out and jump into, that valve is all the way open and somebody is complaining cause they're having a problem with it.

Turn on the system. Fine tune it down. Start there. Get it to where it works and say ok, let's operate a cycle and let's see what it does.

Traditionally your problems go away and it's usually because you got a stuck on valve and it created vacuum up in the top of that. Traditionally that's the issue.

The water meter is an overlooked tool that can help you quickly determine if there's a leak in your customer's irrigation system.

In Part 1 of our Drought Solutions video series, Bob Franchetto, DBDS Maintenance & Construction, shows you how the water meter can help you find and correct leaks.

Video Transcript

Who's been in their water meter, residential or commercial, in the last 30 days?

3, 4....good. That's awesome because we get almost next to nothing when I get a raise of hands. I'm glad you're in your water meters because first off you gotta know where it is on the site and what it is.

That's a huge, huge indicator of what we've got going on and we don't really care about this dial. If this dial here is moving on you, we've got a big leak.

What you wanna look at is this little flow indicator here. This little dial. Sometimes it's blue, sometimes it's a red triangle.

If that flow indicator is moving and we have the irrigation system shut off, we've got a main line break, we've got a leaky valve, we've got all kinds of other things to go.

This is the number one tool on our irrigation sites that gets overlooked. I ask, "What's the water meter doing?"

Man, I don't even know where the water meter is. Clunk, clunk, clunk you go. You know, cause it's buried. They finally find it, you dig it up and sure enough, there's a water meter there.

How are we checking our totals? Your customer is screaming that we are using too much water. Do a monthly check. See what your total is when you're there at the beginning of the month. Go back one month later. See what your total is then.

Do the math between the two numbers. That's how much water you used. Cubic feet or U.S. gallons is how that number is usually read and it will say on the dial right there. Then check your water bill for that site.

Our government agencies are doing averages like crazy. They will take your peak average and reduce it or increase it depending on where they think our temperatures have been.

Now a lot of them now have data recorders on them to where it will electronically send that data to the machine that the guys have. So he never even opens it up.

Is the Water Meter Leaking?

Check to see if your water meter is leaking. If your water meter is leaking on the city side, you're not going to see it. If your water meter is leaking on your side of the property, huge amounts of water that you're gonna pay for and your water meters are leaking.

I run into that. Dude, that's leaking on the city side. You're not getting billed for it, but we're wasting water. Let's get that fixed. It's a city responsibility.

When it starts leaking on your side, that's your responsibility as a property manager. And that happens a lot, so keep an eye on it.

Simple little tool. It's for the low hanging fruit. This is where we could tell what our leaks are in our system and our irrigation techs don't go look at that. Very, very seldom.

How to Check for Leaks

We went through this a little bit. The water meter is running. We see that little blue dial moving out. With the irrigation system turned off, that means the leak is between our meter and our valves. So now on that mainline piece that's supposed to be solid, no leaks. We got a leak in there.

If the backflow is turned off. That's a question. How many backflow prevention devices do we use? Commercial's got everything? Do we use any backflow in residential? Some?

I know we use a lot of anti-siphon valves. Above ground anti-siphon valve - huge opportunity for low hanging fruit right there.

If the backflow is turned off, now we just isolated - we're not the valves anymore, now we're back to the backflow - and we're still leaking, now we know it's on our main that's going from that meter to that main.

If water is running out of the heads on a flat surface, we've got a weeping valve. That valve is leaking. We know that. Let's go and replace and fix that valve. That's the next step into making sure that that is corrected. This is the stuff that gets missed every day.

And then if we've got a slope surface and we've got water running out the heads at the bottom of the slope, that's low head drainage. If there's no check valves in those sprinkler heads, every single time that system shuts off, every bit of water from the valve all the way down to the head in that pipe is gonna leak out. Every single time.

And we're going to do an ROI calculator to show you how much water you can save by putting a check valve in and capturing that water in the pipe so it doesn't run out every time.

So we're being great water purveyors, we're saying "Yeah, you know what I did? I cycle and soak my slopes because I get the water on the slope and it soaks in and then the system shuts off."

If you don't have a check valve in that head, everything that you're cycle and soaking trying to get in the ground just ran out of your pipe and it looks like this:

This is low head drainage right here. Classic. And you know what's so classic about this low head drainage right here and probably this misadjusted sprinkler head right here?

The classic thing about that is your irrigators go driving by that every single day. I know I see it every day. I see it every day on sites. Water on the street, water on the sidewalk, water in the gutters.

And we drive by it and our irrigation tech goes,"Yeah! Irrigation system watered today. Right on! Perfect!"

No, that's not the idea. That's not a visual indicator that the system came on. That's wasted water. That's low hanging fruit.

That's why we need to get in there and look at these kind of things.

It's the stuff we walk by every single day and don't pay attention to is where that 20% savings can come from and it will be way bigger than 20% savings because I've done the math enough times now to know that the numbers will save you water immediately just by corrective actions on this.