So don’t stretch the distance between sprinklers. Will you have multiple valve locations? You need to trust me on this one! So the stream from a 1/4 circle head will pass over the same area 4 times in the same amount of time that it takes for a full circle head to make one pass over the area it waters. But the middle 3 cups are only getting ½ the water of the cups next to the sprinkler. The goal for this app is to help the installer save time and money. For example, you’re designing for 30 PSI. This means that a sprinkler with a radius of 15' with a full nozzle will actually cover a 30' area. 1. So they try to make it look like you can use less sprinklers with their brand. After you’ve bought the sprinklers if you have dry spots, well hey, it’s YOUR problem now! The cost of parts in your area will very. front and back yard. Important: see notes below! The tip of the screw deflects the water which “screws it up” (pun intended) so it doesn’t go as far. . If all or a majority of your rotors will be spaced at 20-29′ apart, then you should probably use larger nozzles than I recommend in the chart. The distance between the sprinkler heads should not be more than 1 foot greater than the width of the planter. Just because the nozzle will screw into the sprinkler body doesn’t mean it’s designed to work with that sprinkler! Sprinkler Head Location and Coverage There are two main criteria for determining the location of sprinkler heads: Because fire sprinklers are heat activated, sprinkler heads must be located high up on or near the ceiling. They don’t show enough overlap! This article is part of the Sprinkler Irrigation Design Tutorial P2904.2.4.2 Obstructions to Coverage End-strip nozzles have notoriously bad patterns, they shouldn’t be more than 10′ from the next head! If we know the area a sprinkler head is covering and the required design density then we can use the following formula: Area x Density = Quantity Therefore if we have a fire sprinkler head which is covering 8m2 and we require 12.5 mm/min 8m2 x 12.5 mm/min = 100 Litres/min When four sprinklers delivering 1.1 gpm (0,25 m3/h) each are added together, they are the equivalent of one full circle sprinkler or 4.4 gpm (1 m3/h). Use a pencil to draw in the sprinkler heads so you can easily make adjustments to the locations later. It’s much easier to remove one than to add one! All parts may not be accounted for. That’s right, 100% overlap of watered areas is REQUIRED or you will get dry spots! The stop and waste is a shutoff valve that drains the downstream water from a main line. (The opening the water goes through is so tiny that the normal expansion of the plastic or metal on a warm evening can close off the water flow!) 1/2 circle . Keep the coverage head-to-head! . The amount of water discharged is dependent on the spacing and density requirements in accordance with NFPA 13. In the diagram below you can see what happens when there are various distances between the sprinklers. Click to read disclaimer and legal agreement. Adjust the locations to make the spacing between sprinklers as even as possible. You must select the appropriate nozzle size for each rotor in order to match the precipitation rates. Spray Heads: Almost all sprinkler manufacturers make their spray heads so that you can mix and match nozzle patterns and the precipitation rates will still match for all the heads. For example, you can use the radius adjustments on the sprinklers to cut down the water in the over-irrigated areas. It is necessary to know the GPM for each head in order to determine which heads will be connected to each valve and in order to determine the size of each pipe in the sprinkler system. So the spacing for this head is 14 ft. (the highest of the 3). Hallelujah! Drip emitter stations very greatly, thus, to keep the parts list more accurate we need some additional input. Write down on your plan the GPM for each sprinkler next to the sprinkler symbol. Best to play it safe. In a shrub area you can eliminate the sprinklers on one side as long as the width of the planter is 4 feet or less- so you can install the sprinklers on one side only. The real world is harsher! The weep hole allows water to escape when the valve is closed. Sometimes it is not practical to obtain perfection! That means each sprinkler throws water ALL the way to the next sprinkler in each direction. This is generally less than 15 for residential properties. Then turn on your sprinkler. . If you are unsure which emitters to choose, here are some popular options / resources. Keep in mind that by choosing multiple locations the parts list won't be as accurate, meaning you may need more valves to control the selected sprinklers. . First, determine what the SPACING is between each head and the others around it. The calculations in this app are based on using schedule 40 PVC pipe and fittings. Find the section of the chart with your desired spacing. Do not expect this to be accurate, in fact, it is intended to estimate 10%-30% high. If your home's water capacity was 10 GPM, you could place 3 heads per zone. 1/4 circle . 5. . If you have rotors that are adjusted for different radii you will need to adjust the nozzle size to compensate for the radius change also! Irrigation Glossary Ignore the radius given by the manufacturer. The area between the lawn (green line) and the edge of the property (brown line) would most likely be planted with shrubs and irrigated separately from the lawn. The Equation. Note the triangular arrangement of the sprinklers, which gives more even coverage. 1" of Water Application Time. In the literature the manufacturer shows different GPM and radius information for each sprinkler nozzle based on the operating pressure (PSI). They are not the answer for all applications, in fact, I only use them in approximately 1 out of 4 systems, but given the right situation, they work very well. Instructions With the help of this calculator you can find the square foot coverage of a drip irrigation sprinkler or spray jet if you have the value of either the diameter, circumference or radius. For 20-29′ spacing between sprinklers- Example: When pricing out a pop-up you include labor, sprinkler head, nozzle, swing joint and the fittings to attach to the lateral. For example, at 35 pounds per square inch (PSI) the 5000 Series Rotor using the 3.0 nozzle will use 3.11 gallons per minute (GPM). The other 3/4 of each sprinkler’s rotation pattern is outside the area. Simply place a bucket (generally a 5-gallon bucket) such that it will catch all the water from the hose bib while it is running. Lakes, ponds and rivers are examples of open sources. But next summer you’re going to look pretty stupid to the neighbors, standing out there with a hose watering the yellow spots your new sprinklers don’t cover! For rotor heads the GPM stays the same no matter how much you reduce the radius! Travelling Irrigator Irrigation Area Rate. $$$ Ching, ching! The calculator will estimate the number of square inches, feet and yards of coverage area, the number of units of water required for irrigation of that area as well as the estimated total cost if you entered the cost value of that volume of water and how much area that given volume of water will irrigate. Changes in spacing between adjacent sprinklers should be made as a gradual transition when possible. By continuing you agree to the use of these cookies or other local storage, as well as the collection, sharing, and use of personal data for personalization of ads or other services. If the calculation in step 2 is the highest flow demand, then calculate the required head pressure otherwise we can use the minimum sprinkler pressure in step 1. (Remember most manufacturer’s give you the radius of the sprinkler, you need to multiply by 2 to get the diameter.) Will you be needing a backflow preventer? 1. Don’t stretch the spacings, use “head to head” spacing. So when you use the radius adjustment on rotors, you tend to get dry spots. There is a conflict between the nozzles recommended for the 20-29′ spacing range of the chart and my previous advice to “avoid using rotors with nozzle flows that are less than 2.5 GPM”. An example of a special pattern would be the nozzles that spray a 4′ x 30′ rectangular pattern. They all say you should listen to me on this! Drip, bubblers and micro sprays are all covered in this section. If you are designing a sprinkler system for an area where the wind blows a lot you should look at the Irrigation and Wind FAQ. MP Rotator Park Strip LeftRadius 14' to 16', MP Rotator Park Strip RightRadius 14' to 16'. Drip irrigation is the ideal complement to traditional irrigation . Privacy Statement The Pennington Seed watering calculator uses some statistics about your location, real time weather and a couple pieces of information from you to calculate the best watering plan for your lawn. A water flow test is often used to determine the water supply available, where a fire hydrant is opened to record pressure and flow values. The writers of those brochures think you are going to look at the overlap and buy the brand of sprinkler that shows the least sprinkler heads. 55 PSI – 5.5 GPM When you use the radius adjustment on a spray you are simply reducing the water pressure by closing a small valve in the nozzle. Important: do not mix different brands of spray heads and nozzles together on the same valve circuit without checking to see that they have the same performance specifications. The number of areas covered by drip, is the total locations for the whole yard. You will probably need to get these from a store that specializes in irrigation sales, rather than a hardware or home store. This website is intended for use by residents of North America only. Go back to the tutorial pressure loss pages to figure out how much pressure will be lost in your sprinkler system. A shrub border helps to reduce the visual impact of the fence (assuming that like most residential properties you have a fence.) You may need to upgrade to the next better model line if you have a large yard! Therefore the building design density should be capable of providing the minimum required density of 0.495/2000. Will you have any zones with spray heads / pop-ups? Yes, I know the package says you can space them farther apart.). The area watered by each sprinkler must overlap substantially the area watered by the adjacent sprinkler. You will need to upgrade to the next model. Shrubs also typically use less than half the water of lawn areas of the same size, saving money spent for water. As with the example above, it is best if you arrange the sprinklers in a triangular pattern. Traveling Big Gun Sprinkler: Calculate the net water application for a given flow rate, efficiency percentage, lane width, and travel speed. To water smaller areas, we recommend drip irrigation . Remember if you reduce the radius of the sprinkler you must reduce the distance between sprinklers by the same distance! Available GPM. 3/4 circle . Protecting Pump against No Flow Damage if a Valve Fails. Most rotors now come with a “nozzle tree” that contains most of the different nozzles for the rotor, so you can change the nozzle sizes if you need to. This creates another problem, however, which is that it really messes up the uniformity of the water. In some circumstances, standard distribution sprinkler heads will not provide enough coverage. PSI (pounds per square inch) Measure and enter the PSI from a tap or hose bib on the property. Example: If you are installing drip in 2 garden boxes and 1 flower bed you would enter 3 total locations. By using this tutorial you agree to be bound by the conditions and limitations listed on the Terms of Use page. The perfect sprinkler would put out a pattern of water that is heaviest right next to the sprinkler, then uniformly declines out to the radius. O.K. Peter Balac | ATOMiC Fire Protection | peter@ ... Go to sprinkler properties, then pick the coverage tab. Fire protection systems design engineers always perform hydraulic calculation for fire fighting systems so as to estimate fire pump size and network pipe sizing Garden Spigots are a great source for large volumes of water to be supplied with a garden hose. . Sprinkler Zone Calculator. Later on you will need to know the flow rate for each sprinkler you use, so it might be helpful to make some notes on the back of your Design Data Form showing the nozzle size and GPM you will need for each different sprinkler you plan to use. (see figure 2) Determining Sprinkler Precipitation Rates The designer needs to know how much water is needed per week or per day to maintain the turf and how … (They never said anything about it to me, I just noticed the new sprinklers a few years later on a visit home from college.) Rotor heads move back and forth across the area to be watered. 3. . Terms of Use If you watered long enough to keep the middle green, the areas around the sprinklers would turn to mud! Fill out the inputs below to determine how long to water and get the best out of your lawn. The estimated cost of parts is generated using average prices found online in 2019. Distance Between Lines . Drip is not included in the custom sprinklers since the drip section should cover all possible emitters regardless of brand. The other reason is that when you reduce the radius you really should also reduce the GPM of the sprinkler. Drip Line Application Rate. Be sure to list the PSI and GPM for each head as given in the manufacturer’s literature, along with the maximum spacing between heads. You will find a tool for measuring GPM below. that the shape and location of the sprinkler arrangement in the design area will be adequately supplied with water in the event of a fire. This is called “triangular spacing” and creates more even water coverage than “square spacing” (ie; lines between 4 heads form a square). Using This Tool. 40 PSI – 4.5 GPM This is known in the industry as “head-to-head coverage or head-to-head spacing”. Bottom line- use the radius adjustment screw on rotors only when nothing else will work. Also, sometimes other nozzle sizes are available separately from the manufacturer, for example low angle nozzles. Next, draw sprinklers around the perimeter of the irrigated area, watching that they are not too far apart (one more time, better too many than too few!). full circle . The rotation speed is the same regardless of whether the rotor is adjusted to water a 1/4 circle or a full circle. Then click "Show Coverage". If the sprinkler system is in a windy area I suggest the majority of the sprinklers be spaced at 45% of the diameter (that’s closer than head to head! Back when I designed my first sprinkler system in High School I wondered why they wanted so much overlap of the sprinklers. In short, to determine the minimum flow from a sprinkler in multiplying the area by the required density, is the actual area of the room used (13'-0" x 13'-0" = 169 sqft) or is it computed the same as the maximum area of coverage for a sprinkler by doubling the furthest distance from adjacent walls [ … That’s the pressure at the sprinkler inlet, not the total pressure available. Example: You note that a spray type head on your plan is a 1/2 circle pattern and the distance to the 3 closest adjacent heads are 13 feet, 12 ft., and 14 ft.. It is recommended that you choose 1 or 2 locations. Prior to locating the design area, there is the question of how many sprinklers are to be included. They water uniformly by broadcasting water in well defined patterns, five feet or more in diameter . Click to read disclaimer and legal agreement. Sprinkler Required: x: Recommended sprinklers to buy: x: Distance Between Sprinklers . The radius of a sprinkler is measured from the position of the sprinkler to the edge of the spray pattern (how far the water is thrown by the sprinkler). Double check calculations and quantities before making your purchases. Percent used is the maximum amount of water you desire to use for irrigation. In areas of unobstructed ceiling construction, where a vertical change in ceiling elevation within the area of sprinkler coverage creates a distance of more than 3 ft between the upper ceiling and the sprinkler deflector, the vertical plane extending down from the ceiling at the change in elevation shall be considered a wall. 30 PSI – 0.8 GPM Sprinklers that are placed closer than 6 feet apart need some special consideration. Sprinklers are intentionally designed to require 100% overlap of watered areas. Avoid using rotors with nozzle flows that are less than 2.5 GPM, except in corners (quarter circle patterns). The most common method is to measure the amount of water supplied from a hose bib on the property. This is referred to as “matched precipitation rates”. After the perimeters are done, then draw the sprinklers in the interior area. But, if the rotor does not spray far enough there is nothing you can do about it without a major expense! If the area is long and narrow (4′ wide or less), use the strip pattern nozzles. We will work hard to improve the calculations and make updates as they become necessary. However, if your sprinkler system will be located in an area with little or no wind you can go ahead and use the smaller nozzles in the chart. CALCULATING THE NUMBER OF POP-UPS REQUIRED HEAD TO HEAD WATERING For proper coverage, space your sprinklers so that the watering patterns overlap. If you must use standard VAN Nozzles, input these sizes using the nozzle that would be considered the next size up, as standard VAN nozzles have a higher GPM. In this example, special spray sprinkler nozzles called “end-strips” and “side-strips” are used. Unfortunately, it’s rather hard to explain. The result is the spacing to use between sprinkler heads and rows of sprinklers. Multiply the diameter of the circular spray pattern of the sprinkler you want by 50 percent, or 0.50. Yes, it takes an extra head to create the triangle pattern, and you need to space the heads a little closer together than the normal maximum on one side to create the “triangle pattern”, but it’s worth the cost. Next, place part-circle heads at each intersection of two lines. Almost all sprinklers have a radius adjustment device on them so that you can reduce the radius of the water throw. As the pressure drops, so does the radius. . 1/4 circle . Using too many sprinkler heads is seldom a problem, using too few sprinklers heads is ALWAYS a disaster! I have a collection of “wish I’d listened to you” letters from people who didn’t take this advice. They tend to have a weak coverage area on either side of the nozzle (the yellow area in the drawing above). Irrigation Tutorials Home But you happen to notice that the rotor manufacturer’s literature says that at 25 PSI, a 1.6 GPM nozzle has a radius of 32 feet. We will strive to improve this function. ft. coverage) Adjustable collar for partial- to full-circle coverage The linear feet of drip is representing the length of the area where you intend to install drip lines. Replacing or Installing Valves, Building Manifolds. A backflow is required for any sprinkler system supplied from culinary (drinking) water. At different pressures, the sprinkler head and nozzle will consume different amounts of water. Generally, a residential sprinkler system will only have 1 or 2 locations. This information may also be publicly available from some municipal water authorities. Important! . Remember, you will lose pressure in the pipes and valves, so the pressure at the sprinkler inlet will be lower than your available pressure! Conversion Formulas So why am I telling you to space it at 25′? Take the sprinkler head watering DIAMETER and multiply it by 0.6 to get the absolute maximum distance that should ever occur between any two adjacent sprinklers. 30 PSI – 2.4 GPM Calculate minimum flow from the MRH with the sprinkler minimum pressure and k-factor Calculate the minimum flow given the system design density and sprinkler head area. It is not recommended that you use standard VAN nozzles sizes 4, 6, 8 and 10 with this tool at this time. There are also spray nozzles called “center-strips” which don’t work as well. Below you will input sprinkler heads and emitters by selecting their nozzle size or emitter GPM. You’re now ready to pencil in the sprinkler head locations on your drawing. In this case the existing building (design) density is more than what is the minimum density required. I was smarter than that, so I stretched them out to save my folks some money! . A simple illustration will help explain. Please help support us by purchasing our app. Calculating the GPM for sprinklers when you reduce the radius is easy: For spray heads you just use the manufacturer’s chart. This will help avoid problems caused by the wind blowing the spray out of the irrigated area. 2. If need be you can even remove or relocate a sprinkler later. To match the precipitation rates between these sprinklers, the quarter circle rotor must have a nozzle that puts out 1/4 the amount of water that the full circle nozzle puts out! The chart tells you the GPM the nozzle must have. Available water supply is rated in gallons per minute (GPM).