Dixon Valves - Pressure Restricting Device - 2.5" FNST x 2.5" MNST - Commonly found on Class I and Class III standpipe system hose outlets.  The "PRD" restricts pressure in the piping system to such a degree that hose lines are not over-pressurized. Manually adjustable.

Option add-on for the Affordable Standpipe Prop. Order up to 10