The Irritrol® 311 Series Valve offers a comprehensive package of performance-enhanced features. Beginning with the reliability of a leak-proof, double-beaded, nylon reinforced Buna-N diaphragm, the strength of glass filled nylon and the expanded range of a maximum working pressure rating of 150 psi, the 311 Series Valve has a list of features that is unmatched. The 311 Valve is also the only anti-siphon valve in the industry with optional pressure regulation, using the OmniReg® modular pressure regulator. Additional features include an upgraded bonnet design, a self-cleaning metering system for dirty water applications and a captive plunger solenoid. In addition, the actuator module is removable as a single unit with the diaphragm and internal components held in place, which means that diaphragm screws and springs do not get lost during installation.