After a lot of research I installed a drip irrigation system consisting of 75ft of ýâ mainline, bubblers and pressure compensating drip emitters. The system has a 20PSI pressure regulator and filter and back flow preventer. The system contains 5 bubblers (2 gph setting) and 10 0.5 gph pressure compensating emitters. Each bubbler is connected to the ýâ mainline via 2ft sections of üâ tubing. Each 0.5 gph pressure compensating emitter is connected to the ýâ mainline via 2ft sections of üâ tubing. The system runs over level ground.

When I turn the system on, the bubblers work as designed, however nothing comes out of the pressure compensating emitters.

HereâÂÂs the part I canâÂÂt figure out. If I remove the end cap at the very end of the mainline, and let the water flow out of the mainline uninterrupted while the system is running, the whole system works properly, the bubblers work as designed and the pressure compensating emitters drip properly. As soon as I replace the end cap at the very end of the mainline, the pressure compensating emitters stop dripping. This leads me to believe itâÂÂs a PSI or Flow issue.

I tested the pressure at the faucet and it was 70psi

I tested the pressure directly after the pressure regulator and it was 70psi (this puzzles me)

I tested the pressure multiple times at the end of the ýâ mainline (with the bubblers turned off) and it was consistently 20psi.

I then calculated the maximum flow from the house. The average flow at the faucet is 9.31 gpm, or 559 gph.

I then calculated the maximum flow from the very end of ýâ mainline drip tube with the bubblers turned off) and it was 6 gpm or 360 gph.

IâÂÂm at a loss, IâÂÂm thinking itâÂÂs a pressure issue, however when I tested the pressure at the end of the mainline it was 20psi.

Any advice would be greatly appreciated.