I'm designing a sprinkler system for my yard. This will be a fairly complex
system, as the area to be watered is fairly large. I'm going to DIY install
the system. I have a good handle on most everything that needs to done,
however, I need help determining my available flow in GPM.
I checked pressure at an outside faucet, and have a static 62 PSI. I checked
flow at the same location and have 8 GPM. I was doubtful of the 8 GPM
reading, because that sillcock is supplied by a 1/2" pipe. So I opened up
the shower and bathtub, and ticked off 14 GPM by using a timer and watching
the gallons go by on my watermeter in the basement.
So, which reading is correct? Is there a better, more accurate way to
determine GPM? I really want to get this right. I have a 1" watermeter,
which has a full 1" ID poly supply pipe. The supply pipe is 50 ft. long,
from the street to my house.
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace the
3/4" with 1"? Or will such a short length of pipe matter? I plan to use 1
1/4" PVC going to the zone valves as well. Is this OK?
Thanks for any advice!