VRO RETURN VR2-I, VR5-I and VR7-I are valves of no return with spring, with screwed cartridge, for applications in blocks or panels, for courses up to 300 l / min. They are powered in three sizes, with ¼ ”BSP threading, ¾ and 1" ¼. The opening pressures are available are 0.5 bar, 5 bar or 10 bar.