Pressure regulator with shutoff mechanism

A pressure regulator comprising:

• a body having a body inlet, a body outlet, and a fluid passageway defined therebetween for allowing a fluid to be dispensed therethrough, the body further comprising a pressure control chamber adapted to receive a control fluid at a control pressure;
• a valve disposed in the fluid passageway for restricting flow of the fluid through the fluid passageway;
• a regulating member operatively connected to the valve for adjusting the position of the valve so as to maintain the fluid in the fluid passageway at a nominal pressure, the regulating member comprising:
• a flexible regulating membrane extending adjacent to the fluid passageway, the flexible regulating membrane being operatively connected to the valve such that movement of the flexible regulating membrane moves the valve;
• a resilient regulating member operatively connected to the flexible regulating membrane, the resilient regulating member being adapted for counteracting the nominal pressure to limit movement of the flexible regulating membrane such that the valve is moved to a position corresponding to the nominal pressure;
• and
• a linking member having a lower end and an upper end, the linking member operatively connected to the valve, the linking member extending through the flexible regulating membrane, and wherein at least a portion of the linking member is disposed within the resilient regulating member;
• a pressure sensor disposed between the pressure control chamber and the fluid passageway for sensing a difference between the nominal pressure and the control pressure, the pressure sensor comprising a flexible shutoff membrane extending between the control chamber and the fluid passageway, the flexible shutoff membrane being adapted to move when the difference between the nominal pressure and the control pressure changes, the flexible shutoff membrane being operatively connected to the movable valve member, and wherein the resilient regulating member is disposed between the flexible regulating membrane and the flexible shutoff membrane;
• a relief spring disposed around the linking member, the relief spring operatively connected to the flexible regulating membrane;
• a retainer ring secured to the linking member, wherein the relief spring is prevented from moving away from the linking member by the retainer ring;
• and
• a resilient shutoff member operatively connected to the linking member, the valve, and the pressure sensor for closing the valve when the difference between the nominal pressure and the control pressure is below a predetermined threshold value.