Lawn Sprinkler Tips

Hurricane Gustave is in the Gulf of Mexico and quickly approaching land with a projected patch with Louisiana right in the middle. Much of Louisiana and certain areas in Mississippi have had mandatory evacuation.

It doesn’t appear that we’ll be nailed dead on here in Niceville, Bluewater, Fort Walton Beach, Navarre, Pensacola, Santa Rosa Beach, and Panama City Beach Area, bu there will still be tropical storm force winds to deal with, along with a projected 3′ – 6′ storm surge from Hurricane Gustav. That surge can put houses that are on the water in danger as there irrigation pumps can get easily damaged once submerged in, or even heavily sprayed salt water. Also, if trees come up-rooted, many pipes will also come up-rooted and have to be repaired. We stocked up on ice today, canned goods, water, propane, charcoal, and more. We topped off gas in all the work trucks and personal vehicles yesterday before the prices went up too much

Hopefully we are all spared from major damage as I want everyone to remain safe. Just remember to always be prepared.

Scott
http://www.autolawnsprinklers.com

If your landscape irrigation system’s water source is from a well with a lot of minerals such as iron or other natural debris, you may have to deal with clogged nozzles a lot more frequently than systems that run off of cleaner wells or municipal/city water supplies.

Spray nozzles come with the screens separate and must be installed prior to installing the nozzle on the spray head. This screen will catch the debris and save the spray nozzle. You can easily wash out or just replace the screen for much cheaper than the nozzle.

Rotary nozzles have a screen already attached, so the installation is one step. If the rotatory nozzle screen becomes clogged, you can easily snap the screen off and clean or replace. However, if debris gets into the rotary nozzle, than it is usually very difficult to save the rotatory nozzle and you’ll have to replace the whole thing, not just the screen.

Normal rotor heads (not rotary nozzle on spray heads) are the toughest with rougher water sources. Sprays and Rotary Nozzles will have much more maintenance on the dirtier water sources, so keep this in consideration when designing your system.

Scott
http://www.autolawnsprinklers.com

We just got done replacing another submersible pump. This pump was inside a 4″ PVC well and was a 3hp (horse power) 50 gpm (gallons per minuet) pump that was hanging on 1&1/4″ schedule 80 PVC drop pipe. This pump’s power source was supplied with standard residential 1 phase power, not commercial 3 phase electrical which I have worked with on occasion.

Every 20 feet was an 1&1/4″ galvanized threaded coupling. The well was approximately 360′ feet and the pump was hanging 160′ feet down in the well. The water table was approximately 60 feet. I would have used at least 1&1/2″ or 2″ PVC schedule 80 pipe instead of the 1&1/4″ pipe. We got just under 40 gallons per minute from the pump at open discharge. The reason for this is because of the distance to water and the size of the drop pipe.

If the water table was higher, the 3hp 50 gpm pump would deliver more (or a higher volume of) water. Also, the drop pipe is restricting the volume and thus pressure. To top this all off, the irrigation system was over-sized. What I mean by this is that most of the zones were demanding too much water or more water than the pump could keep up with.

There are a couple of possible solutions to this problem. The 160′ feet of 1&1/4″ drop pipe can be replaced with 2″ schedule 80, or all the zones demanding too many gallons per minute can be lowered by changing nozzles and/or sprinkler heads. For example, there is one particular zone with twelve 3.0 (three gallons per minute per head) that demanding about 36 gpms . By changing just half of the nozzles to 2.0′s, I can lower the demand of this zone by 6 gallons per minute.

Of course, you want to try and achieve matched precipitation, but in practice it is difficult to get it exact and imitate mother nature’s precise even watering. So, you want to do your best to design, layout, and build a sprinkler system that will water as evenly and efficiently as possible. Some irrigation contractors can do this better than others…

The system also operated with a pressure tank, specifically a bladder or diaphragm tank and uses a 30/50 psi pressure switch. We also installed a new pressure tank which came pre-charged with air. I lowered the psi in the tank to 28psi before installing and filling it with water. So, the system actually operates on a 28/48 psi cut-on and cut-off range.

Submersible pumps are powerful because the push directly rather than having to create a vacuum or suction like a centrifugal pump, or use hydraulics to force water to the surface like a jet pump. Replacing your submersible pump can be easy or hard depending on your knowledge, skill, tools, and strength. If you have never replaced a sub-pump, I do not recommend doing it. You should only do it if you have had replaced these types of pumps with an experienced person with you to help teach you.

Scott
http://www.autolawnsprinklers.com

Today we replaced a 3hp 50 gpm (3 horse power/ 50 gallons per minute) submersible pump. The well the 362 feet deep. The pump was hanging on the standard 20 foot sticks of 1&1/4″ schedule 80 PVC. The pump / drop pipe was only hanging 160 feet. The depth to the water table was close to 90 feet.

We replaced the old pump and 12-gauge solid strand twisted 4 wire. The colors are red, black, yellow, and green. The type of sub pump that we use is called a “3 wire motor” even though there are four wires, they don’t count the green ground wire I guess! There are also two wire submersible motors available (actually have three wires including the ground), but I do not use them and recommend against them.

The three wire motor has the main advantage of utilizing a piece called a control box which contains the starter capacitors and relays and this box is installed above ground. A two wire motor has the start capacitor together with the motor. The reason why this is bad is because the most common thing for to go out on a sub is the start capacitor or relay and if your system only has a three wire motor, you will have to extract and replace the whole pump! If you use a three wire motor, when the start capacitor or relay in the control box goes out, it is easily replaced above ground without having to remove 200, 400, 600 feet of pipe or even more!

If you do not have a specialty truck with a wench and proper pipe clamps this process can be a labor intensive task, but can be done with the use of another specialty tool. A pipe pulling clamp will help hold the pipe has you pull it up and remove it. Every twenty (20ft) feet there will be a threaded connection that you must undo. The pipe pulling clamp help hold the weight of the rest of the pipe and sub pump so that it does not fall to the bottom of the well!

Be prepared do get covered in water because every 20 feet you will have to unscrew the metal or galvanized coupling and water will rush out fast on you! I have seen a few sub pump hanging with schedule 40 PVC, on glue fittings, but the majority of subs are on 1&1/4″, 1&1/2″ or 2″ schedule 80 male threaded pipe ends.

When replacing submersible pumps, we normally replace all the wire just to be on the safe side. You can end up nicking the wire as the pump is pulled up and removed, plus the wires could have a short in them, so it is best to put new wire in. I don’t replace the drop pipe unless it looks in horrible shape, or is the wrong type.

It’s not an easy job, but a satisfying one, that is for sure. If you ever have any questions regarding sprinklers, irrigation, and pumps, feel free to contact me and I’d be glad to help you!

Scott Young
http://www.autolawnsprinklers.com

I’m about to go to remove a stuck foot valve from a 2″ PVC well. The foot valve hangs on 1&1/4″ schedule 40 PVC drop pipe and has a jet close to the bottom of the drop pipe. The well is about 50 feet and the drop pipe is only about 35 feet.

The foot valve assemblies here are assembled with pieces called spring dogs & rubber packers which expand to help hold prime with the foot valve. Some contractors use “leathers” to hold prime, but the leathers tend to break down sooner over time and can also get stuck when being pulled up…we prefer the spring dog and rubber grommet/packer system. However, other issues and factors beyond our control produce problems that must be solved with some out of the box thinking and good old American Ingenuity.

I will give away a few trade secrets, but not all..maybe I’ll sell those later. Here are a few tips and solutions to help you get out a stuck foot valve or drop pipe on a jet pump setup:

1. If the drop pipe is broken, remove the PVC out of well that has broken off.

2. Use an “extractor” a.k.a. “1&/4″ tap” assembled to the end of a stick 1&1/4″ galvanized.

3. Insert the extractor inside the 1&1/4 drop pipe and tighten to make new threads inside

4. Once the extractor is definitively tapped in, then you must slowly back off (turn the 1&1/4 pipe counter clockwise to loosen the neoprene grommet (this part of the step is not necessary if your drop pipe hangs with leathers.

5. Gently pull up the drop pipe. Do not yank! This will cause pipe breakage! You must apply equal force on both side, so it helps to have a 2nd hand. You may need to cut it every 20 feet if your are not experienced. If you do it carefully you can avoid cutting the drop pipe and string it up in some trees if there are some nearby. If you do have to cut, make sure to use “tapered” 11&1/4″ thin couplings for your joints or connections.

6. Your drop pipe is removed from the well and you can now replace your foot valve! Be sure to clean or replace the jet if needed. It corrodes over time and also sediment gets built up inside which can seriously reduce flow and eventually clog up the jet. If the jet is just clogged and not corroded you can clean out the passage ways with a flat head screwdriver and rinsing it out with water. If it is really corroded, then I would recommend replacing it with a new one.

Scott

http://www.autolawnsprinklers.com

The two most commonly used type of heads in automatic lawn sprinkler systems are either rotor/ rotary style heads or spray heads that do not rotate. Rotors rotate or move and thus have a lower precipitation rate than spray heads. In other words it takes a zone of rotors longer to apply the same amount of water per square foot than fixed spray heads.

Spray heads do not rotate and have a higher precipitation rate. That is they get the area watering quicker or faster. It is common sense really. Since the water is constantly being saturated and not moved past like with a rotor, it will get watered faster.

However, rotors and sprays have the place,. It all depends on design and size of the landscape on what type of heads are best to use. The average house will have a combination of rotors and sprays zones and maybe even drip zones.

I like rotor heads because they do not tend to get clogged as easy as spray head nozzles. Most rotors seem more durable than the average spray head also. Rotors cover larger areas so, there are less heads used. But spray heads have there place where it is just too small for rotors.

The main advantage of sprays is that you can get your watering done faster. If you have a limited window, then spray heads are the faster at applying water down to the landscape. Rotor heads are great for larger areas and will require less maintenance, but you will have to water the rotor heads slightly longer, about 3X longer than sprays for the same amount of water. They both have their pros & cons, but are both needed in specific situations.

Scott
http://www.autolawnsprinklers.com