How many sprinklers can I have on a zone or station?

This is determined by several variables: Static water pressure, service line size, and the flow rate of each head or sprinkler that will be used on each zone.

How deep do I bury the gear drives, pop-up impacts, or spring-loaded pop-ups?

Install at ground level.

One or more of the sprinkler heads are weeping or running continuously.

This is generally due to a ruptured or torn diaphragm in one or more of the electric control valves. Refer to the following valve articles: “Valve Not Turning Off” and “How to Replace a Sprinkler Valve Parts”

Satellite or impact head will not trip or return.

Be sure there is enough water pressure or flow (GPM) to operate the number of sprinklers that you have on each zone or station. The average flow required per head is approx. 3.5 GPM. Check to be sure there is no blockage in the nozzle of the head assembly. If not, and you are not getting the proper radius, there may be too many heads on a zone or station. If the distance or radius meets the specifications, the impact head may be defective.

The radius or distance of the sprinkler does not meet the specifications.

There may be too many heads on a zone. There may be a blockage in the nozzle, sprinkler inlet, control valve, or piping. Also, if the control valve has a flow control, it may be turned down. If the sprinkler has a filter, it may need to be cleaned.

There are dry areas in front of or around the sprinkler head.

This is generally caused by improper sprinkler head spacing. Sprinklers should be spaced for 100% overlap or head-to-head coverage. This will allow each adjacent head to distribute water in front of or around the sprinkler.

Sprinklers not Rotating or Oscillating

• We have only two types of sprinkler heads that rotate/oscillate; gear-driven and impact heads. Between the two there is only one similar problem that can cause them not to rotate and that would be a lack of pressure or flow. To determine that, find out the GPM usage of the sprinklers they have, and also how many they have on that one zone. Then find out their pressure and pipe size and use the chart in the layout guide to determine their maximum flow. If the flow of the sprinklers on the line is greater than the maximum flow through their pipe, that would be the problem. From this point on, the problems would be different from one to the other.
• For our impact heads, there are only two other things that will cause this problem. The first would be if there is debris on the moving parts of the sprinkler. The second would be that there is just something defective with the sprinkler and it would need to be replaced.
• For our gear-driven heads you will need to unscrew the top lid to take the guts of the sprinkler out of the canister. On the bottom of these sprinklers is a filter, the filter may be clogged which would hinder the flow of water so there may not be enough water flowing through. They can remove the filter and clean it. Another thing that can cause the gear-driven heads to stop rotating is if the nozzle shoots out. Without the nozzle in there, the water usage through the sprinkler will be too great and can cause it not to rotate. The only other thing that can cause the problem is if there is something defective with the internal gears which at that point the sprinkler would have to be replaced.

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Tags: core, Maintenance, sprinkler, troubleshooting