Patent ID: 7157168

Claim:
A regulator comprising: a body having a primary port for introducing a fluid under pressure and a secondary port for delivering the fluid regulated to a desired pressure; a valve head displaceably disposed in said body for being unseated from and seated on a valve seat for opening and closing a fluid passage which interconnects said primary port and said secondary port; a rod coupled to said valve head for displacement in unison with the valve head; a diaphragm engaging said rod and flexible for displacing said rod in an axial direction of said rod; a nozzle comprising a tube body having a suction hole directed toward said secondary port; and a back pressure chamber defined at an end of said rod for acting in a direction to cancel out a pressure applied to said valve head, and an aspirator chamber defined closely to said valve head for developing a pressure lower than a pressure in said secondary port due to a suction caused by said nozzle, said rod having a communication hole which provides fluid communication between said back pressure chamber and said aspirator chamber, wherein said regulator is incorporated in a fuel cell system having a fuel cell stack having an anode and a cathode, said regulator being mounted in a bypass passage between a pressure controller for discharging a pressure to the secondary port which has been regulated depending on a pilot pressure, and an anode humidifier for humidifying a fuel delivered from an ejector to a predetermined humidity and supplying the humidified fuel to said fuel cell stack.