When installing a drip irrigation system, start by organizing all the pieces by size and type—fittings, drip emitters, sprayers, minisprinklers, misters, bubblers, goof plugs, and stakes—and place them into separate marked bags.

Connect the drip system to your water supply, construct a head assembly, and then position the water lines where you want them. Turn on the water to flush out the lines and then install the various components. Should you change your mind about a component or about the positioning of the lines, you can always make adjustments as you go along.

Connecting a head assembly at the hose bibb
A head assembly connects at a hose bibb just as a hose would, by threading on. The flow rate for the assembly will be less than that of the faucet, so make sure the combined flow of the circuit’s watering devices does not exceed the maximum flow rate of the assembly.

To construct the head assembly at the hose bibb, screw on a vacuum breaker, a filter, a pressure regulator, and then a thread-to-tubing compression adapter. If you want the system to have a timer, screw that on first. If you want a fertilizer injector, screw that on after the vacuum breaker. Do not tighten any of the connections with a wrench; the washers should seal with simple hand-tightening.

Connecting a head assembly at the control valve
If you are connecting a drip irrigation system to a sprinkler system, the head assembly connects to the control valves of the sprinkler system with piping. Wrap the threads on the piping with pipe- thread tape and then tighten by hand or very gently with a wrench. The parts are marked with arrows; assemble them so that the arrows point in the same direction as the flow of water.

To connect a head assembly at the control valve, screw on the filter, then the pressure regulator, and then a thread-to-tubing adapter. If you want a fertilizer injector, install it before the filter.