Blocking device for pipelines for the passage of pressurized gas, of the pilot-operated type, and pressure regulator for said blocking device

A blocking device for pipelines for the passage of pressurized gas, the blocking device comprising:

• a blocking valve, in turn comprising:
• a connection body, for connection between an upstream pipe and a downstream pipe, inside which there are defined an upstream chamber, having an upstream pressure therein, connected to said upstream pipe, a downstream chamber, having a downstream pressure therein, connected to said downstream pipe, and a passage opening between said upstream and downstream chambers;
• a movable shutter, for obstructing said passage opening;
• a stem carrying said movable shutter, said movable shutter being fixed to said stem;
• a fluid-dynamic actuator configured to translate said stem along a main axis of said stem itself;
• thrust means configured to bring said movable shutter from an open operating position to a closed operating position;
• the blocking device also comprising:
• a control system for the controlled actuation of said fluid-dynamic actuator, comprising a by-pass group for equalizing the upstream pressure in said upstream chamber and the downstream pressure in said downstream chamber, and a pressure reducer group interconnected with said by-pass group, said pressure reducer group being configured to receive a motorization fluid at a supply pressure as input, and to supply said fluid-dynamic actuator with a motorization pressure through a motorization line,
• said control system comprises a pressure differential selector device configured to detect a signal of said upstream pressure and a signal of said supply pressure and to determine alternatively:
• the passage of a supply fluid through said pressure reducer towards said fluid-dynamic actuator if the pressure difference between said upstream pressure and said supply pressure is less than a predetermined balancing pressure difference;
• the interception of said supply fluid and the failure to supply said fluid-dynamic actuator if the pressure difference between said upstream pressure and said supply pressure is greater than or equal to said balancing pressure difference.