Available in 2”, 3”, 4” and 6” models, the Viking Model G Dry Valve is offered completely pre-assembled including the water supply control valve, air supervisory switch, and alarm pressure switch. An external reset feature makes it simple to reset the valve by re-establishing air pressure to the system to pressurize the valve’s unique priming chamber. In a fire condition, air pressure is lost and the priming chamber compresses, allowing water to pass through the valve and into the sprinkler system piping.