Question
QUESTION: Dear Mr. Schaefer,

I have a problem with my Rainbird 5000 plus sprinklers and hope that you find the time to answer my question.

My spinkling system contains of 3 sprinklers (5000 plus) and approx. 40 meters of tubing.

When I turn on the water the sprinkler heads won't pop out every time. Some weeks ago they did every time, but nowadays not anymore. To be more precise, the sprinklers remain in the transition movement and the water shoots out of the nozzle and the head at the same time (mostly between white gasket and head). If I pull the sprinkler head upwards manually, the sprinklers begin working as intended.
The problem is that they do not opo up by themselves automatically.
Another interesting point: If I turn off the water the three sprinkler heads go back down. If I now turn on the water again (not all sprinklers are in the default OFF position completely yet) all sprinklers pop out as intended and begin working again. The problem only occurs if all sprinklers went back to their default off position and remained there for some small duration.

Data of my infrastructure:
The water pressure is set to 4.5 bar directly at the connection of my house to the water supply of my town. So even with the friction inside the tubing, the water pressure at the sprinkler itself should be at least > 1.7 bar, no?

Next step for me is to verify if there is any possible leakage but for me its not plausible that the sprinklers work as intended under some special circumstances. It would really help me if you could help me.

Thanks and kind regards,
Dennis Marburg

ANSWER: Hey Dennis, pressure is relative to what you are trying to accomplish, but what you need to determine is how many gallons (for you liters) per minute you are supplying to the heads. For instance, you say you ran the tubing 120 meters, what size is the tubing? Lets say the tubing was only 1/2" in diameter (yours in centimeters 2.5?) You might only get 5 gallons per minute (roughly 12 liters per minute), at the heads (for all the heads). If you used a bigger pipe (lets say 3/4", or yours maybe 4 centimeters?) you could get roughly 12 gallons per minute (roughly 30 liters per minute). Each head has a nozzle with a particular gallon per minute rating(yours liters per minute). Lets say you are getting 12 liters per minute, but each head uses 5 liters per minute (5 LPM times 3 heads =15 LPM) you only have 12 LPM and that is why the heads are not working. First thing you could try doing, is changing the nozzles in the 5000 head to the smallest nozzle, and see if that helps you out. To determine how many liters per minute you are getting, simply turn the system on, and go to your water meter (make sure no other water in the house is running), and watch the meter for one minute, and see how many liters you have used in that one minute. You might have to run a bigger line, or only put 1 or 2 heads per valve. Good luck and have a great day.

---------- FOLLOW-UP ----------


5000+   QUESTION: Hi Jim,

thank you for your advice.
My tubing has an inner diameter of 25 cm.
I measured a flow rate of approx. 900 liters per hour.
Compared to the data sheet of the 5000 plus I would need approx. 1110 - 1260 liters per hour (at a pressure between 3.5 to 4.5 bar) with the stadard angle 1.5 nozzles.
So I mounted the 1.0 low angle nozzles which need only 720 - 810 liters per hour. Unfortunately the heads are not rising even though it should work.
I think next step would be acquiring this light blue nozzle kit in which 1.0 and even .75 nozzles (standard angle) are included... But they are quite a pain to get here in Germany.
I attached a photo of the sprinkler head in its peculiar position after opening the valve. Is it normal that this amount of water bypasses the head? It appears to be more than at the two other sprinkler heads in the same position.
Since the system already worked for a short time, I assume that this head might be malfunctioning...
-> Do you know what the usual defect look like on these type of sprinklers?

Kind regards,
Dennis

Answer
Hey Dennis, it seems like you are losing more water than normal through the seal around the stem. How long have the heads been in? Also make sure the cap on top of the head is tightened to the body. If you keep having this much water leaking, I would suggest replacing the heads.
It appears that all the water is being lost, because the head is not sealing properly. I think you mentioned last time, that if you pull the heads up (so they seal), the system seems to work correctly. Or at least try replacing one head (the worst one) and see if that helps. Good luck and have a great day.