Adding 4 spray heads---possible?

[Flutie7NFL]

I have done various repairs on EXISTING systems, I am not skilled on creating new ones. Our church had some sort of breakage under an Oak tree, so I rerouted the one inch line which was schedule 40 and utilized the same. They would like four more spray heads (3 halves, 1 quarter) added to where the line ends (about another 30' further). The current pressure does not seem overly robust to me. Currently on the spray zone are 9 halves, 6 quarters and one full, pipe run about 110 feet. I used a pressure gauge on a hose bib next to the valves and got 45 psi. I made up a connection to read the pressure at the line's end while the zone was running and got 22. I simply am not certain that adding more is feasible. If I were to try, should the line drop to 3/4" for two heads and then to 1/2" for the last two? Or 1/2" for all four? I have done a lot of researching to try and figure this out with friction loss tables, but am unclear on this. Opinions? Thank you!!!!

 

[Breplum]

You may be able to convert the existing heads to the pressure compensating small rotary heads and just maybe it would work.
I wouldn't put money on it, though.

 

[Sponsor]

 

[sprinklesplash]

It seems like you’ve done solid work rerouting the existing system, but adding more spray heads to the current setup might push the limits of your system’s pressure. Given that you’re already seeing a significant drop from 45 psi at the valves to 22 psi at the end of the line, adding four more spray heads could further reduce the pressure, leading to underperformance. The friction loss over the 110-foot run and the number of heads already connected likely contribute to the pressure drop, which is why the current pressure doesn't seem robust.

If you decide to add the new heads, dropping the pipe size to 3/4" for the first two heads and then down to 1/2" for the last two could help maintain some pressure, but it’s a tricky balance. Using 1/2" for all four heads might reduce pressure too much. Given the variables involved and the potential for further pressure drops, it may be wise to consult with a professional or consider upgrading the system, possibly by adding another zone, to better handle the additional load.