Valve for controlling the differential pressure for a hydraulic installation, having: - a valve body provided with an inlet, an outlet, a channel that places the inlet in fluid communication with the outlet, and an auxiliary chamber, - a sealing element which separates the channel from the auxiliary chamber, - a control inlet in fluid communication with the auxiliary chamber, - a fluid intercepting element (3, 5, 22) at least partly operating in the channel, wherein the valve can be controlled in a first operative configuration, wherein the fluid intercepting element (3, 5, 22) defines -in the channel - a fluid through-flow opening between the inlet and the outlet having a variable width; - a control member (10, 10c, 15, 25, 26) connected to the valve body and active on the fluid intercepting element to control the valve in the first operative configuration, the valve being characterised in that the control member is active on the fluid intercepting element for controlling the valve at least in a second operative configuration and at least in a third operative configuration, wherein: - in the second operative configuration the fluid intercepting element (3, 5, 22) is blocked - with respect to the body - in a first position conferring to the through-flow opening a pre-set width independent from the value taken by a pressure differential between a pressure (P-) present in the channel and a pressure (P+) present in the auxiliary chamber; - in the third operative configuration, the fluid intercepting element (3, 5, 22) is blocked - with respect to the body - in a second position defining a complete fluid-tight closure of the through-flow opening between the inlet and the outlet of the valve, irrespective of the value taken by the pressure differential. - a valve body provided with an inlet, an outlet, a channel that places the inlet in fluid communication with the outlet, and an auxiliary chamber, - a sealing element which separates the channel from the auxiliary chamber, - a control inlet in fluid communication with the auxiliary chamber, - a fluid intercepting element (3, 5, 22) at least partly operating in the channel, wherein the valve can be controlled in a first operative configuration, wherein the fluid intercepting element (3, 5, 22) defines -in the channel - a fluid through-flow opening between the inlet and the outlet having a variable width; - a control member (10, 10c, 15, 25, 26) connected to the valve body and active on the fluid intercepting element to control the valve in the first operative configuration, - in the second operative configuration the fluid intercepting element (3, 5, 22) is blocked - with respect to the body - in a first position conferring to the through-flow opening a pre-set width independent from the value taken by a pressure differential between a pressure (P-) present in the channel and a pressure (P+) present in the auxiliary chamber; - in the third operative configuration, the fluid intercepting element (3, 5, 22) is blocked - with respect to the body - in a second position defining a complete fluid-tight closure of the through-flow opening between the inlet and the outlet of the valve, irrespective of the value taken by the pressure differential.