Dul, Pressure is the dependent on how many outlets or sprinklers are in operation. If you have only one riser running then it will receive all the system pressure. The flow rate will be dependent on the cross-sectional area of the pipe and pressure. Systems are designed to handle the way the irrigation is set up knowing the flow rates of all the system irrigation heads and the overall system pressure. You could calculate what you can do by knowing each component's flow rate and pressure drop. But most people do things by trial and error. Which way do you want to go. To calculate the design, you need to some homework. For starters, the system's total flow rate and pressure. Would you know how to find those? Aloha

In-ground boxes were used; however, they were overgrown with grass. We finally managed to locate all 7 zone valves and the master valve. It only took about 10 hours, but we found them all, and cleaned them out. That was 80% of the time spent on this project. Lesson learned...keep those valve cover areas weedeated out every week!! The root cause appears to be sand from our well. We get this really fine sand from the Paluxy Sands in our well water. We had severe sand issues for a while after first digging the well, and apparently it was enough to cause problems in the irrigation system 3 years later! The sand got into the diaphragms in the valves and blocked the little pin holes that allow the valves to close. That, combined with lowering the water pressure slightly, would not allow the valves to close. Thus, multiple stations would be running at the same time. Everything is working better than before now, thank goodness! I found a great site for electrical troubleshooting that helped a lot (link below); that helped narrow down the possibilities right off the bat. Here is a link that might be useful: Sprinkler System Electrical Troubleshooting

troy, I may be missing something and I would appreciate if it was explained to me. Residential controllers are usually 2-4 programs for different plant types(sprinklers vs drip, etc). Any program can be accessed at any time as long as times don't match. Different zones can not be run at the same time. So an example: ProgA zone1 can be 9:00 am for 5 minutes duration and ProgB zone 1 can be 9:15 am for 5 minutes which gives zone1 a rest to soak in between waterings. Both ProgA and ProgB can not water zone1 at 9:00am nor can ProgA zone1 and ProgB zone 2 run at 9:00am. Two zones running at the same time will lower the flow and pressure of both zones. That is the reason for having zones in the first place if the system isdesigned properly. JMHO Aloha

I have a new Rainbird system. When first installed all the zones (6 total) worked fine. The contractor came out to install one power control switch that he didn't have before and now my last two zones won't come on like before. I got them to run by messing with the zone valves in the control box for their area. But now it's either 5 or 6 but not both at the proper time. Any ideas on how to make the proper setting for those valves? Or do you think I might have another problem? Any help appreciated!