Typically, though, a sprinkler system zone will boast 5 to 6 rotor heads and/or 8 to 10 spray heads.
If your home's water capacity was 10 GPM, you could place 3 heads per zone. Consult the Performance Charts on or inside the box your sprinkler head came in for your head's exact performance data, or locate the performance data in the Support area of this website.
The rules vary by system type. Pipe-schedule systems and hydraulically calculated systems with a density at or over 0.25 gallons per minute per square foot have a 12-foot (3.7 meters) maximum distance between sprinklers. Hydraulically calculated systems with less density have the standard 15-foot (4.6-meter) maximum.
This will primarily be determined by the total flow rate and pressure you have available at your source. For example, you generally have a flow rate of 10 gpm from a ¾-inch spigot where you connect your hose. With your 10 gpm flow rate at your spigot, you could run two sprinklers at 5 gpm each.
Most spray and rotator heads are designed to work their best at about 30 psi. When pressure is lower, the watering radius will be reduced, so you may need to place your heads closer together to get the coverage you need. Higher pressures – those above about 40 psi – will cause the head to mist or fog.
For many sprinklers, the recommended operating water pressure ranges between 30-40 pounds PSI. A pressure regulator ensures that water pressure consistently stays within this recommended PSI range, regardless of the water pressure before it reaches the sprinkler.
A common rule that is followed for obstructions within 18 inches of the sprinkler deflector is the “three times rule”. This requires sprinklers to be positioned away from obstructions a minimum or three times the maximum dimension of the obstruction.
The high volume pressurised water stream gets harder to be distributed evenly. Thus, that size of impact sprinklers have another small (4-6 mm) nozzle to water the area for the closer area to the sprinkler. The main stream will start spreading in the air after a certain distance to the sprinkler head.
Sprinklers should be set to run for about 30 to 35 minutes at a time twice a week. Your goal is at least 1″ of water a week for your lawn. When it's hot and dry, double the water times while still trying to water just 2 or 3 days a week.
I'd suggest trying energizing only one zone at a time, to see if just one zone behaves differently than having them all on at the same time. How many sprinklers do you have? If you have a bunch, and they are all on at the same time, then the pressure would be low, and likely not enough to "pop up" the heads.
The optimum operating pressure for most residential sprinkler heads is between 30 and 50 pounds per square inch (PSI). With correct water pressure, each head will perform the way they were designed, and the result will be even spray-patterns and efficient use of water.
Running multiple zones at once is usually not possible due water-pressure and flow limitations at residential properties. As with any standard irrigation controller, you can wire multiple solenoids/valves to the same zone output if you want.
Meaning that spray heads should never be placed further than 15 ft. apart as this would create dry spots (i.e. dead grass) in your lawn. It is always important to install sprinklers with overlap for full coverage. Spray heads have a higher application rate than other sprinkler heads.
Rotor Sprinkler Head
Rotor sprinkler heads are driven by internal gears and are often referred to as gear drive sprinklers. Since they are not driven by an impact arm like impact sprinklers, it results in smoother, gentler performance and a more even water distribution across your irrigation area.
Gear-Driven Rotor Sprinkler Heads
They offer a multitude of advantages over impact rotors, such as low cost, quiet operation, and various spray patterns. Gear driven rotors often require less maintenance because the enclosed body protects the drive mechanism from dirt and lawn debris.
Nothing should be in that area between the bottom of the sprinkler heads and the imaginary horizontal plane parallel to the ceiling that is 18 inches below. This is done to allow an even and unobstructed spray pattern from the sprinklers when triggered to extinguish the fire.
The “Four Times Rule” is really just an extension of the “three times rule” however it covers extended coverage sprinklers and the maximum clearance is 36 inches (0.9144 m).
Timer problems are the most common cause of intermittent low pressure in one sprinkler system zone. The timer for this zone may be a bit behind the others, causing a delay for full water pressure to reach the affected zone. Or, the timer may turn the zone on and off a few times or may not turn it on at all.
The PVC pipe should be buried minimum 200mm below finished ground level to protect it. When you are ready to install your pop-up sprinklers, we recommend installing them on Articulated Risers or 'Swing Joints'. These are an assembly of pipe and fittings that connect the lateral pipe to the pop-up sprinklers.
A good rule to follow when considering the depth of a sprinkler system is, measure the body of your most commonly used sprinkler heads, then add 2 inches. For example, if you are using Rain Bird 1804 pop-up sprinkler heads, the body is 6”, so I would recommend that the sprinkler piping be 8 inches deep in this case.