The Pratissoli RA2 and RATL (manual bypass lever) pressure regulator valve is a manually- adjustable, pressure-operated device which, according to its setting, limits the pump/system pressure by conveying the excess of water to the by-pass. Moreover, when the outlet flow is blocked, this device totally releases the flow – and keeps under pressure the portion of the system following the valve, while it reduces the pressure in the portion of the system preceding the valve. 210 Bar max pressure. 20-230 Lpm flow. 85°C max water temperature. Trapped pressure valve. Brass body. Pressure adjusting knob. 1"BSPF inlet. 3/4"BSPF outlet. 1"1/4BSPF bypass.