Jess Stryker's
Landscape Sprinkler Design Tutorial
Step #1
Introduction to Irrigation Design
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Jess Stryker's |
Read this!
(It will help you see where the rest of the tutorial is going. It's a much more pleasant trip when you have a map!)
A quick primer on sprinklers.
Sprinklers require two things to operate- water flow and water pressure. When a sprinkler system design fails, it is almost always the result of a lack of water pressure. This is important because, if you are like 99% of the people using this tutorial, you are thinking solely in terms of water flow. "How much water do I need (or have available) for my sprinkler system?" That's an important question to ask, but it must go hand in hand with its sister question, "How much pressure will I have at the sprinkler?" The "at the sprinkler" part of that question is critical! Allow me to demonstrate by means of a simple, if not somewhat stupid, demonstration.
Go get a sprinkler, any sprinkler will do fine, even one you put on the end of a hose. Now get a big bucket of water. 5 gallons is an ideal size. Now place the sprinkler on the ground (somewhere outside is strongly recommended) and pour the water into the sprinkler inlet. Did the sprinkler operate correctly? Did it water a good size area? NO? Why not? It had plenty of water! Ahh... no water pressure! The water you poured into it didn't have any pressure to make the sprinkler operate.
Water pressure is the ENERGY that makes the sprinkler do its thing. Water pressure is like the gasoline for the car. Flow is like the distance the car travels. No gas, no travel. No water pressure, no water flow. (Yes, Ms. Ph.D. in hydraulics, that's a bad analogy- but it works for most people.)
Now think of the inverse of the above example, because we're going to be using it in our sprinkler design. We know that water requires pressure to flow. It also stands to reason that just as the car uses up the gas when it travels, the water also uses up the pressure as it flows! So from the moment the water enters your yard, it is losing pressure. It loses some pressure when it goes through a water meter. It loses some more pressure as it moves through the pipes. Squeezing through the backflow preventer and valves eats up more pressure. But here is the key- after it gets to the sprinkler head there still must be enough pressure left to make the sprinkler head work. If there isn't, it's just like the sprinkler in the example above. All the water in the world won't make it work without pressure! How much pressure is lost in each of those items? It varies. You can control how much pressure is lost, and that, my friends, is what sprinkler system design is all about!
So here's sprinkler design in a nutshell: Sprinkler design is simply manipulating out how much water pressure is lost between the point the water enters your yard and the sprinkler head. That's right, you are about to learn how to manipulate! (Come on, you've always had a secret desire to be able to manipulate, right?)
At the bottom of each page of the tutorials is a link called "glossary". If you run into a term you don't know, click on glossary and look it up. Warning: The glossary also has a lot of my bad puns and weird humor in it.
Here's a brief overview of how we'll approach this:
Step #1: You'll learn how to accurately measure your yard and then sketch out the area to be irrigated. Next some information needs to be obtained. Don't worry, I'll tell you how and where to get it. We'll also make an "educated guess" at an Initial Flow Rate, which will serve as a starting point for the flow and pressure manipulations mentioned earlier.
Step #2: We'll take a look at those things that will "eat up" your water pressure as the water moves to the sprinklers. I'll show you how to find out how much pressure each one of those items will use. While we're at it, you'll learn about sprinkler heads, valves, backflow preventers and all the other equipment that will go into your new sprinkler system. Then we will manipulate those pressure losses and end up with the actual flow and pressure values you will use for your sprinkler system. Don't panic, there's a lot of information to cover, but I will lead you through it item by item. It will be easy if you don't freak out on me!
Step #3: Here's where we actually start drawing sprinklers. Finally! You will learn a lot more about sprinklers in step #3. It's a long wait, but if you had started drawing sprinklers back in step 1 or 2, like some tutorials do, you'd be erasing them now!
Step #4: Here's where you'll divide your sprinkler system up into zones and lay out the piping routes. This is where we're going to make the right decisions to create a sprinkler system that uses less water than most and gives you healthier plants. Bad sprinkler design is a major cause of turf disease.
Step #5: Finally, we will determine the size of each pipe and clean up a few small details.
Step #6: Wait a minute, there isn't a step 6. Congratulations, you're now a sprinkler system designer!
If you're in a hurry you can skip the rest of this page. The remaining topics on this page are:
How to make the tutorial easier to read on your screen.
Tips for printing the tutorials.
Introduction to Irrigation Design.
How to use this Tutorial:
This first section is for folks who hate to read things on computer screens. It gives some tips for making it a LOT easier. If you are comfortable with the screen or insist on wasting a lot of paper printing this whole tutorial, skim down to the next section of this page.
You will need a browser that supports GIF and JPEG graphics to make maximum use of this tutorial. That's pretty much all of them except Lynx. If you don't know what Lynx is, it is one of the original browsers and displays text only. Some people still use it, because it's very fast, and since most banner ads are pictures, you don't see the ads.
I've tried to make the tutorials as user friendly as possible, while maintaining compatibility with most older computer systems. There is very little formatting specified in the code, and you can customize almost everything to your liking. I designed the web pages to work in pretty much any browser and avoided using code which is specific to only one browser. So you won't find any of those "best if viewed with The Greatest Browser on Earth" tag lines here!
Some tips:
If the text lines are too long, simply adjust the browser window, so that it is narrower (usually by clicking the lower right corner of the window and dragging to the desired size). The text width will adjust down via the text wrap feature in your browser.
If the text size is too small or too large, select a different default text size for your browser.
For Mozilla Firefox and older versions of Internet Explorer click on "View" in the top menu and then click on "Text Size". For Internet Explorer v.7 and higher click on "Page" at the right top side of the browser window, then click on "Text Size".
If you don't like the font used for the text, you can change it by changing the default font for your browser. The default font settings can typically be changed from the browser's menu bar.
Don't like the gray background? I used the gray background because it is easier on the eyes when reading on the computer screen. If you really hate it, you can change it too. First, try simply adjusting the brightness control on your monitor. If that doesn't do the trick, you can change the color.
Now you should be able to comfortably read the tutorials on your screen.
Printing the Tutorials
A lot of people like to print out the tutorials. A word of warning- have plenty of paper and ink handy! The number of printed pages depends on your font selection, font size selection, page setup, and browser. It works better if printed in color because some of the graphics use colors to show different features. Some people have complained that some pages of the tutorials do not completely print. I don't have a solution for that, it's a local problem with your computer. Sorry, I don't have a pre-printed version of the tutorial available.
Both Internet Explorer and Netscape have a bad habit of chopping off the right side of many of the tables in the tutorial when they are printed. Check the pages after they are printed for missing tables.
Before printing I suggest:
Adjust the text size to a smaller size in order to reduce the amount of paper used.
Free Designs:
Irrigation design is a deceptively simple looking task. A great number of over simplified "design it yourself" pamphlets have not helped the situation. A few of those pamphlets have even been scanned onto web pages (I was hoping they would be allowed to die a merciful death!). The current industry trend is toward offering homeowners free "computerized" designs in place of the oversimplified guides. I'm not opposed to these free design offers; however you should be aware that there is usually a condition attached (such as buy your irrigation materials from the designer). I will offer the following warning: I have yet to see a computer program that can perform "hands off" irrigation design. Every irrigation design software package I have encountered requires MAJOR tweaking of every design to obtain a good irrigation system. Thus the design you get will only be as good as the person running the computer. If you have ever dealt with tech support for any product, you probably can see the problem. Some operators are really knowledgeable, but some... well, you've been there. So here's what to do. Go ahead and get the free design if you want, then sit down with this tutorial and make sure the free design measures up!
Sprinkler System Design is not easy!
So what is it that makes irrigation design so difficult that even the best artificial intelligence computer programs stumble on it? Part of the reason for the difficulty is that some of the hydraulic principles are rather abstract and hard to understand. The primary difficulty, however, is that there are many, many variables involved in even the simplest irrigation design. This then leads to my next problem, which is: "how do I create a tutorial which can get you through all those variables without frying your brain?"
My answer to the problem of making a top-quality tutorial is to attempt to simplify the design process, so that it will take a minimum of time and learning, while not over-simplifying it to the level of those previously-mentioned pamphlets. What I have done for this tutorial is simplified the mathematics equations, used charts and tables where possible, substituted constant values for a few variables, thrown in lots of sample drawings, and glossed over much of the complex hydraulic theory. That eliminates a good portion of the problem. In some instances, however, I simply can't make assumptions without sacrificing quality. So you will be asked from time to time to provide data. I will do my best to guide you toward quick and accurate sources from which you can obtain that data. When possible, I will provide data values for you to choose from. In a few instances, I have made an estimation of the value for you. In those cases I have used a "75% conservative" value. In other words, I have not used the most conservative value available, as to do so would result in gross over-design most of the time. Rather I have used a relatively conservative value, which will work in the vast majority of situations. The goal is that when one of these estimated values is too conservative, it will be balanced by another elsewhere which is too liberal. In the interest of accuracy, I will provide a technical note whenever I make an assumption. I don't want to do anything behind your back!
Now, let's get started! Select "Next Page of Tutorial" below.
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Jess Stryker's Irrigation Tutorials
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