Timeline for Do I need a pump for my sprinkler zones that are minus 70 feet elevation?
Current License: CC BY-SA 4.0
7 events
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| Aug 29, 2021 at 0:40 | comment | added | Mark | @user227963 - Your sprinkler heads are not in series, they are in parallel. If they were in series the water would flow through all of them. Instead, it flows through a single pipe - some of it flows out through the first head and the rest continues down the pipe to the other heads. The pressure drop through each sprinkler head is equal to the pressure in the pipe at that point because all the pressure is lost in going out through the sprinkler head. But the pressure in the pipe will not be meaningfully different between points a few inches before and a few inches after each sprinkler. | |
| Apr 9, 2019 at 5:30 | comment | added | Solar Mike | Why not try the calculator with your tank and pipe information... | |
| Apr 9, 2019 at 5:22 | comment | added | user227963 | Can you elaborate ? I am not sure which question or random thought of mine above you were referring to ... Thank you. | |
| Apr 8, 2019 at 16:47 | comment | added | Solar Mike | The inlet pressure changes, have a look at this calculator : engineeringtoolbox.com/flow-liquid-water-tank-d_1753.html | |
| Apr 8, 2019 at 16:24 | comment | added | user227963 | BTW, the reason I think this pipe has a very high flow rate is that I looked at the table on hy-techroofdrains.com/water-flow-through-a-pipe and I see that 2.5" pipe @ 40 psi is 421 GPM ... does that still hold true if pressure is 0psi at the top of the pipe and 40 at the bottom ? Am I misjudging this rough calculation somehow ? | |
| Apr 8, 2019 at 16:14 | comment | added | user227963 | From the research I have done, each individual sprinkler head represents a cumulative drop in FLOW (gpm) but I don't see anyone specifying a pressure drop per head. I feel intuitively that if I have four heads in a row (in a series - not on their own stubs) that pressure PSI must drop after each head but I am having trouble verifying that intuition ... FWIW, each zone will only have 4-6 sprinklers so perhaps I have so few that it won't matter, given my HUGE flow rate ? | |
| Apr 8, 2019 at 8:22 | history | answered | Solar Mike | CC BY-SA 4.0 |