Pressure regulator with over-pressure safety shut-off feature

A pressure regulator, comprising:

• a body having a first end, a second end, a through-opening communicating said ends, and having a portion extending into said opening to form an abutment surface facing toward said body first end, said body first end being exposed to fluid at a relatively-high supply pressure, said body second end being exposed to said fluid at a relatively-low pressure-to-be-regulated;
• an element arranged in said body opening and having a first end, a second end, and a through-bore communicating said ends, said element being mounted for sealed sliding movement along said body opening toward and away from said abutment surface;
• a regulating poppet mounted for movement toward and away from said element second end for controlling the flow of fluid through said through-bore;
• an actuator arranged to sense the magnitude of such regulated pressure and selectively operable to permit said regulating poppet to move away from said element second end when such sensed pressure is less than a predetermined pressure, to cause said regulating poppet to close said element through-bore when such sensed pressure is substantially equal to said predetermined pressure, and to exert on said element second end a force substantially proportional to the magnitude of such sensed pressure above said predetermined pressure which urges said element to move away from said abutment surface;
• a seat arranged within said body opening and operative to sealingly close said element first end when said element has moved sufficiently away from said abutment surface to engage said seat;
• and
• a vent passageway provided between said element and body and operable to selectively communicate said element through-bore with said regulated pressure when said regulating poppet has closed said element through-bore and when said element has been moved away from said abutment surface to engage said seat.