Properly designed drip irrigation systems begin with what is called the Head Assembly. The Head Assembly provides protection to the drip emitters and micro sprinklers from particles that may enter the system, and reduces or regulates the incoming pressure of the water entering the drip irrigation system to the appropriate operating pressure of 25 PSI, which is within the range of recommended operating pressures.
A manual or automatic optional control valve (optional) may be added at the start a drip irrigation system. This assembly can be attached to a faucet, the most common method used to start a drip irrigation installation in home gardening. If using this option to start a system, begin the installation from an outdoor faucet (spigot). If you are planning to automate the system with a battery operated controller or a hose end timer connect the timer to the faucet first, before the backflow device.