PA VB16 pressure regulating unloader valve with discharge control pressure with very low readings.. At gun-lance closure, the water flow is bypassed at reduced pressure. Sturdy steel and brass construction. By-pass control actuated at very low pressure values with reduced pressure in the delivery line when gun is shut. Quick start at gun opening assures gradual pressure reset, essential for use on endothermic engines. Specially designed check valve prevents jamming and vibrations even in presence of sand and scales. Working typology protected by registered patent. 500 Bar rated pressure. 80 Lpm max flow. 90°C rated water temperature. Flow sensitive valve. Soft Start action.