Finished the bucket test today and the best balance of flow and pressure is 12.5 GPM @ 40 PSI. At that pressure the pump kept running and the flow was consistent over the hour that I let it run. If I reduced the flow, the pressure increased but, the pump would eventually kick off.
This measurement is taken right after the PVB before the mainline connects to the first valve. Estimating the other losses in the system:
- 100' of 1" poly mainline to the farthest valve - 4PSI loss
- Valve (Richdel 204AT) I couldn't find data on this valve - estimate 5 PSI loss
- Laterals and fittings - longest run about 80' of 1" poly - 4 PSI loss
This leaves me with about 27 PSI at the sprinklers. I intend to use all sprays or MP Rotators. If I design with this information, can I just put the heads a little closer together than the 30 PSI spacing? Also, if I limit the flow through each zone to about 10 GPM, will I get good coverage and minimize the pump cycling? That flow rate would also leave a little flow for the occasional toilet flush while the sprinklers are running...
Tom in Michigan