Drip zones need regulation because the working pressure of a drip zone is lower than any other type of system. Hunter offers two options for pressure regulation - a 25 psi(1.7 bars/170 kPa) and a 40 psi(2.8 bars/280 kPa) version.
The 25 psi version is suited for point source systems using individual emitters, and types of systems that are not pressure compensating, or systems using small supply tubing.
The 40 psi system is aimed at pressure compensating systems like Hunter's PLD inline emitter tubing. PLD emitters compensate for pressure delivered from 15 to 50 psi(1.03-3.45 bars)(103.43 to 344.75 kPa). The 40 psi regulator reduces the pressure to something the emitters can handle, ensuring the accurate amount of water supplied and long term performance.