Method for operating a pressure regulator for an operative gas, said pressure regulator comprising: - a flow duct for said operative gas; - a shutter arranged along said flow duct in such a way as to define a narrowing in said flow duct, said narrowing being suited to cause a pressure drop in said operative gas from a feeding pressure, present in the area of said flow duct upstream of said shutter with respect to the flow direction of said operative gas, to a delivery pressure, present in the area of said flow duct downstream of said shutter, said shutter being movable in such a way as to modify the cross section of said narrowing; - a motorisation chamber placed in communication with said downstream area, at least partially delimited by a first movable wall, said first movable wall being connected to said shutter so that the increase in said delivery pressure causes a corresponding movement of said shutter that is suited to reduce said cross section of said narrowing, and vice versa; - elastic means configured in such a way as to counteract the pressure force exerted by said operative gas on said first movable wall by exerting on said first movable wall a predefined force tending to move said shutter so as to increase said cross section of said narrowing; charachterised in that said pressure regulator comprises: - a compensation chamber distinct from said motorisation chamber, filled with a compensation gas and at least partially delimited by a second movable wall connected to said shutter in such a way as to be able to transfer the pressure force of said compensation gas to said shutter so as to pilot said pressure regulator and characterised in that the method includes the operation of regulating, moment by moment, the pressure of said compensation gas according to said delivery pressure. - a flow duct for said operative gas; - a shutter arranged along said flow duct in such a way as to define a narrowing in said flow duct, said narrowing being suited to cause a pressure drop in said operative gas from a feeding pressure, present in the area of said flow duct upstream of said shutter with respect to the flow direction of said operative gas, to a delivery pressure, present in the area of said flow duct downstream of said shutter, said shutter being movable in such a way as to modify the cross section of said narrowing; - a motorisation chamber placed in communication with said downstream area, at least partially delimited by a first movable wall, said first movable wall being connected to said shutter so that the increase in said delivery pressure causes a corresponding movement of said shutter that is suited to reduce said cross section of said narrowing, and vice versa; - elastic means configured in such a way as to counteract the pressure force exerted by said operative gas on said first movable wall by exerting on said first movable wall a predefined force tending to move said shutter so as to increase said cross section of said narrowing; - a compensation chamber distinct from said motorisation chamber, filled with a compensation gas and at least partially delimited by a second movable wall connected to said shutter in such a way as to be able to transfer the pressure force of said compensation gas to said shutter so as to pilot said pressure regulator and