Adjusting OPV – Rancilio Silvia Remove the top cover for access to the OPV – see detailed instructions. At arrow position 1, loosen the nut by turning it counter-clockwise until it reaches the coupling at arrow position 2. Turn the coupling at arrow position 2 clockwise into the elbow to increase pressure, and counter-clockwise away from elbow to decrease pump pressure. Once completed, tighten the nut at arrow position 1 so that it tightens up against the elbow.